Training Overview SolidCast

Casting Process Design

From Start to Finish

Version 7.2.2 System Overview

6/23/09

What are the goals of Casting ProcessDesign?

• Make good (acceptable) castings

• Make them right the first time

• Make them in the most efficient way possible

What this means to the foundry tactically:

• Shorter lead times

• Higher first-part quality

• Higher quality during the life of the part

• Less scrap

• Fewer customer returns

• Lower cost of production

• Lower energy consumption

What this means to the foundrystrategically:

• Higher profitability

• More customer responsiveness

• Better overall customer relationship

• Better market position

• Ability to fend off competition

The spectrum of foundry activity

Marketing

Process Design

Productionmanagement &

control

Strategic Planning

The pieces of process design

CustomerSpecs and Data

Initial DesignConcepts

DesignVerification

DesignOptimization




DesignVerification

DesignOptimization

CAD Import




DesignVerification

DesignOptimization

Riser DesignGating Design

CAD Import




DesignVerification

DesignOptimization


CAD Import

Flow AnalysisSolidification




DesignVerification

DesignOptimization

CAD Import


Flow AnalysisSolidification

Optimization

Integrated “Up-Front” Design Tools

The Riser Design Wizard™

Automatic sizing and location ofrisers

Traditional Approach

Modulus =Volume

Surface Area

New Approach

“Thermal” Modulus calculated fromsolidification analysis of “naked” casting

The Gating Design Wizard™

Automatic calculation of gatingcomponent sizes and Optimal Fill

Time

Horizontal Gating

Ref: Basic Principles of Gating Design (AFS)

Vertical Gating

Ref: Modern Casting Tech Report 755 (Disamatic)

Design Verification

Finite Difference Solidification Modeling

CFD (Computational Fluid Dynamics) Flow Modeling

Design Optimization

The Basic Simulation Process

1. Select alloy and mold materials.

2. Import model shapes from CAD, or create shapes withinSOLIDCast, for the casting, risers, gating, sleeves, chills,etc.

3. Mesh the model, and run the simulation.

4. Plot the results, looking at progressive solidification andprediction of shrinkage or microporosity.

5. If results are NOT satisfactory, go back to Step 1 or 2.Make changes in gating, risering, the part, or add sleeves,chills, adjust pouring temperature, etc. Then proceed toStep 3 again.

6. If results are satisfactory, you are done.

Some Basic Points

• SOLIDCast deals with 3D models. This means we need tobe aware of the directions X, Y and Z.

• X and Y are considered HORIZONTAL directions.

• Z is considered VERTICAL. +Z is up, -Z is down.

• In SOLIDCast, you create projects. A project consists ofmodels, meshes and simulations. Usually a project refersto one part number, and the various design iterationsassociated with that part. The steps in the project areshown on the left side of the SOLIDCast screen – this isthe “Project Tree”

Blocks

Creating Basic Shapes

SolidCylinders

SpheresHollow

Cylinders

Enter Dimensions

Creating Solids of Revolution

DXF File fromCAD System

Specify Axis ofRevolution and

Degrees ofRotation

ADG File fromAFSCad

Sketch ShapeOn-Screen

Creating Solids of Extrusion

DXF File fromCAD System

Specify Limitsof Extrusion

ADG File fromAFSCad

Sketch ShapeOn-Screen

STL File

STL File

IGES, STEP,etc.

FileConverter

Note: A File Converter may be a CAD system (examples: SolidWorks, SolidEdge,ProEngineer) or a viewing/conversion program such as SolidView.

Importing 3D Shapes from CAD

“Composite” Models

Solid Cylinder

Solid ofRevolution

Block

Solid ofRevolution

Solid ofRevolution

Solid ofExtrusion

STL File

Solid Cylinder

Importing Files from CAD

Required File Format: STL (Binary)

1. Start SOLIDCast

2. Select File… New Model

3. On the Tool Bar, click “Add a shape to theModel”

4. Click the “down” arrow on the Shape Typefield. Move to the bottom of the list of ShapeTypes and select “STL File”.

5. Click the “File” button.

6. Locate the STL file to load, select it and click“Open”

7. Click the “Add Shape” button.

8. Click “Zoom Options” on the Tool Bar andselect “Zoom Full”

Questions

What’s the difference between ASCII and binary STL files?

ASCII files are text files. Binary files are encoded.

How can I tell which type of file I have?

If you don’t know, open the file in Windows WordPad. Ifyou can read it, it’s ASCII. If not, it’s binary.

What about units – Inches and mm?

If your system is set to English units, SOLIDCastassumes the STL file is inches. If in metric units,SOLIDCast assumes it’s mm. Before selecting the file,you can specifically select inches or mm on the AddShape window. After importing, you can checkdimensions just by clicking on a couple of points. If it’swrong, delete the shape and re-import.

Questions

What do I do if I only have an ACSII STL file?

Use the SOLIDCast STL Convert Utility Program toconvert the ASCII file to binary.

Creating Basic Shapes inSOLIDCast

Cylinders, Hollow Cylinders, Spheresand Rectangular Blocks


2. Click the “down” arrow on the Shape Typefield. Select the type of shape you want tocreate.

3. Enter the required coordinates anddimensions, and select the material type.

4. Click the “Add Shape” button.

Questions

What if I enter the wrong dimensions, or want to changesomething later?

You can select the shape, and then select Edit… EditSelected Shapes and change the shape parameters.

What is the Priority Number?

Priority numbers are important ONLY when two shapes ofDIFFERENT MATERIAL overlap. The shape with thelowest Priority Number ends up in the overlap region.

Questions

What is the difference between Casting Material and RiserMaterial?

They are both casting alloy, and act exactly the sameduring the simulation. The main difference is that thesystem will display a different weight summary for eachmaterial type, so you can break the total metal weight intothe casting and the rigging, to calculate yield.

Also, you can specify a different HTC at the riser/moldsurfaces and the casting/mold surfaces, in permanentmold simulation, when you use these different materialtypes.

Sketching Shapes on theScreen

For making solids of extrusion orrevolution.

1. First, you can (optionally) set the “Snap” byselecting “Tools”, “System Parameters”,“Model & Sim”… then enter a “Snap to Grid”dimension.


3. Click the “down” arrow on the Shape Typefield. Select the type of shape you want tocreate, either Revolved or Extruded.

4. Start sketching on the screen.

5. Click the check mark on the Tool Bar to closethe shape.

6. Enter the shape information in the window.

7. Click “Add Shape”

Selecting Shapes to Edit

You can move, rotate, copy, hide,group, ungroup, edit properties or

delete selected shapes.

1. On the Tool Bar, click “Select Shape Mode”,which is an arrow pointing to the upper left.

2. Click on any shape in the model. This shapewill turn a different color (usually red) toindicate that it is selected.

3. You can select MULTIPLE SHAPES bypressing the Ctrl key when you click on theshapes.

Moving Selected Shapes

1. Once shapes are selected, then select “Edit”and Move Selected Shapes.

2. You can enter X, Y or Z distance to move theshape.

3. You can move the shape around using mouseclicks in an orthogonal view.

4. You can move a shape from one “Pick Point”on a surface to another “Pick Point”.

Copying Selected Shapes

1. Once shapes are selected, then select “Edit”and Copy Selected Shapes.

2. You can perform a Linear Copy operation,which creates one or more copies offset fromthe original at a given X,Y,Z offset distance…or…

3. You can perform a Ring Copy, which creates aseries of copies, spaced evenly around anaxis (for example, every 30 degrees aroundthe Z axis would result in 11 copies of theoriginal shape, plus the original).

Editing Selected ShapeProperties

1. Once a shape is selected, then select “Edit”and Edit Selected Shapes.

2. You can alter any shape characteristic whichappears in the window.

Hiding Selected Shapes

Sometimes it is convenient to hide oneor more shapes so that you can moreclearly see other shapes in the model.

1. Once shapes are selected, then select “Show”and Hide Selection.

2. Later, to display hidden shapes again, select“Show” and Show All.

Selecting Casting Alloys

1. Select “Model” and then “Materials List” fromthe menu.

2. Select the tab labeled “Casting”

3. Press the “From DB” button

4. Use the slider bar to move through the list.

5. Select the alloy and click “OK”

6. If you want to adjust Pouring Temperature,change the temperature listed as InitialTemperature.

Setting Cast Iron Properties

1. You will need to know Carbon, SiliconPhosphorus content as well as CastingModulus and Temperature in the mold. If youdon’t know the Casting Modulus, use theRiser Design Wizard on the casting shape.

2. Run the Iron Property Calculation (VDG.exe)Utility Program to get % solid and amount ofexpansion/contraction.

3. In SOLIDCast, select Model… Materials List…Casting. Select an iron alloy (for example, CIDI Ferr for Ductile Iron).

4. Now select the Curves tab.

5. Click the Ductile Iron button.

6. Enter Carbon & Silicon to generate coolingcurves.

7. Click on the Draw Shrk Curve button.

8. Locate the point with the % solid andexpansion/contraction from the VDG program.For mold wall expansion, add 1% or 2%contraction. Click on this point and then clickDone.

9. Click on Set CF Solid Pt button and move theCFS line to the % solid calculated by the VDGprogram.

10. To save this, go to the Casting tab, enter aunique name, and click the Add to DB button.

Selecting Mold Materials

1. Select “Model” and then “Materials List” fromthe menu.

2. Select the tab labeled “Mold”

3. On the left side are materials in the Database.On the right side are materials to be used inthe model. To select materials from theDatabase, use the slider bar, select thematerial, then click “Add to list”.

4. You can add as many materials as you want tothe list on the right. SOLIDCast will maintainthis list until you change it.

5. To remove a mold material from the list,highlight it and click “Remove from list”.

Component Files

You can select any or all shapes within a model, andmake a Component File. This can be used to create

a library of standard shapes (like risers, or gatingcomponents, or chills) so you don’t have to recreate

these multiple times.

This can also be used to make a file of a completecasting model, to transfer to another computer.

Component Files contain both the geometry and thematerial properties of the selected shapes.

1. Select the shapes you want to make aComponent File out of… or select Edit…Select All Shapes to get the whole model.

2. Select Model… Export… Selection and enter aname for the Component File.

3. This will create a file with an extension of.mdc which contains the shape(s).

4. To use this on another model, select Model…Import… SOLIDCast 5.x Component and thenselect the file. This will bring these shapesinto the new model.

Planes of Symmetry

Planes of Symmetry can be used to section aSYMMETRICAL MODEL along center lines. This

allows you to simulate one-half or one-quarter of thecasting to save time.

Later, you can use the Mirror function to mirror thedata back into the portions of the model which were

not simulated (this step is optional).

1. Select Model… Options… Planes of Symmetry

2. Select the Plane you want to activate (lower orupper X, Y or Z)

3. Enter the location (if it’s not 0)

4. Press the Activate button.

5. Meshing and simulation will occur only onthose portions of the model which are not cutoff by the Planes of Symmetry.

6. After running the simulation, if you want tomirror results, select Simulation… Mirror.

Filling Simulation

SOLIDCast will perform a simple filling simulationwhich shows progressive temperature loss of the

liquid metal during filling of the cavity.

You need to specify the Fill Time (or calculate it withthe Gating Design Wizard) and place Fill Material at

the entry points for the liquid metal.

For a more advanced fill calculation which showstemperature and velocity using true CFD fluid

simulation, see the FLOWCast optional module.

Setting the Fill Time• Select Model… Materials List… Casting

• At the bottom of the screen, enter the FillTime.

Placing Fill Material• Create a shape at the entry point of the liquid

metal. Usually, this will be a cylinder at thetop of the sprue. It may also be just gatesattached to the casting. The shape must belarge enough to be meshed with at least onerow of nodes.

• Under Material Type, select Fill Material.

• Where the Fill Material touches Casting orRiser Material, the filling simulation will begin.

Cloning a Model

If you want to make a copy of a model, for thepurpose of making a change and running a newsimulation, use the Clone Model feature. This

creates a duplicate model which you can edit andchange.

1. On the Project Tree, select the model you wantto clone.

2. Select File… Clone Model.

3. A new model will be created.

Meshing a Model

Meshing is required before runningany simulation. This breaks the model

down into small cubical elements.

1. Select “Model” and then “Create Mesh” fromthe menu.

2. Select Node Size or Number of Nodes.

3. Select Type of Mold.

4. Select Mold Material.

5. Select Mold Thickness.

6. Select Open Top or Closed Top.

7. Click OK.

Weight Calculation

After meshing, the system will displayweights of all materials.

1. Select the Mesh entry on the Project Tree.

2. From the menu, select Weights

3. A table of weights will be displayed.

Running a Simulation

1. Highlight the mesh on the Project Tree (the liston the left side of the SOLIDCast screen).

2. From the menu, select “Mesh” and then “StartSimulation”

3. To run a simulation under “normal”conditions, press OK.

Sand Castings

• Normally, we neglect internal(material/material) HTC’s when performingsand casting simulation

• In the Materials List, select the HT Coefficientstab. Make sure the check box labeled UseInternal HT Coefficients is blank. For theExternal HT Coefficient, we normally use avalue of 1.5

• When meshing, normally we select aRectangular Mold.

Sand Castings, Cont’d

• Select only as much sand thickness as youneed to absorb the heat (1-2” for smallercastings, 5-6” for large castings)

• Use Open Top if you have open risers, useClosed Top if you have blind risers

Investment Castings

• Select Investment Shell for your moldmaterial. Set the Initial Temperature of theshell to your Preheat Temperature.

• To create the shell, you have two options:

1 – When meshing, select Shell Mold Type

2 – Use the Shell Maker utility program tocreate an STL file representing the shell

• After meshing, be sure to use View Factorcalculator to account for radiant heatexchange. Select Mesh… View FactorCalculation.

Investment Castings, Cont’d

• Why use the Shell Maker? If you have thingswhich are external to the shell such asinsulating wrap on the gating, or a bed ofvermiculite in which the shell is submerged,creating a shell as part of the model makes iteasier to accurately create the model.

• To use ShellMaker, you must have an STL fileof the casting AND the gating. If parts of themodel were created with SOLIDCast basicshapes, you can create an STL file using theSTL from Model Utility Program.

Investment Castings, Cont’d

• From the Tools, and select the Shell MakerUtility Program. Specify the STL file and thesurface quality. This will create an STL filerepresenting the shell.

• Now, in SOLIDCast select Add a Shape, selectSTL and select the shell file. Designate it asShell Material, and give it a large PriorityNumber (like 8 or 9).

• Later when you mesh, select the None optionfor Mold Type (you already have a mold aspart of the model).

Permanent Mold Castings

• Make sure that Internal HT Coefficients areturned ON (in Materials List, go to the HTCoefficient tab and click Use Internal HTCoefficients)

• Specify an HTC for each actual (physical)interface in the model. If two materials are incontact, there should be an HTC specified forthe surface between them.

• If the mold is rectangular in shape, you canuse the Rectangular Mold option in meshing.If you want a specific mold shape, that shouldbe created as part of the model, then selectNone under Mold Type in meshing.

Permanent Mold Castings, Cont’d

• Make gates and risers out of Riser Material, sothat you can specify a different HTC at thosesurfaces than at the casting surface.

• If you can’t separate the gates and risers (ifthey are all one STL file) you can make twotypes of mold material, say Steel1 and Steel2.Make the mold of Steel1, and make insertsaround the gates and risers using Steel2, thenset up the HTC’s accordingly. Between Steel1and Steel2, use a very high HTC (say, 5000)which will thermally “join” these into onematerial.


• Mesh twice… once with fewer nodes (call this“Coarse” and once with more nodes (call this“Fine”). Ratio of nodes may be anywherefrom 1:4 to 1:10.

• When you run the simulation, specifyPermanent Mold as the Type, and select theCoarse mesh as the Warmup mesh.

• If you have FLOWCast installed, you canselect which filling algorithm to use for thewarmup cycles and for the final cycle.


• For aluminum permanent mold castings, werecommend using the $HTRED.410 file in theSOLIDCast folder. This is a text file containingthe number 0.30. This reduces the metal/moldHTC by 70% at the solidus point, per researchperformed by Dr. Sciama at Pechiney.

Viewing Simulation Results

This is where you plot the results ofsimulations to look at progressive

solidification, riser feeding, shrinkagepredictions, etc.

This is done when the simulation iscomplete.

1. Double-click the simulation on the ProjectTree (the list on the left side of the SOLIDCastscreen).

2. The Simulation Status window will appear.Close this window.

3. To plot results, click “Simulation” on themenu. Various options will appear.

Plotting Options

Iso-Surface Plot: Plots one value as a 3D surfaceinside a transparent casting.

Cut Plane Plot: Plots on a 2D plane cut throughthe casting

CastPic Plot: Makes a 3D image of the casting,with data indicated by color mapping.

CastScan Movies: Makes movie (AVI) files usingmultiple, multi-colored iso-surfaces within thecasting.

Example Iso-Surface Plot showingProgressive Solidification

Example Cut Plane Plot

Example CastPic Plots showingProgressive Solidification

Solidification Pattern


Casting Sectioned on YZCenterline


Casting Sectioned on XZCenterline

Example CastPic Plots showing Areasof Potential Shrinkage

Casting Sectioned on YZCenterline

Casting Sectioned on XZ Plane -7” from CL

Casting Sectioned on XZ Plane 8” from CL

Question: How do I capture theseimages for documenting simulation

results?

Use a screen capture utility such as Pizazz, whichallows you to set up the Print Screen key so that,each time you press the key, a new image file iscreated. These images can later be imported intoWord, PowerPoint, or other documentationprogram.

Movie-Making Options

Iso-Surface Movie: Makes a movie of progressivevalues of Iso-Surface plots.

Cut Plane Movie: Makes of movie of progressivevalues on a 2D cut plane.

CastPic Movie: Makes a 3D movie image of thecasting, with data indicated by color mapping.

CastScan Movies:

Progressive: Movie of progressive values of adata item (usually progressive solidification)

Rotating: Rotating movie showing results(usually shrinkage defects)

Plot Data:

Temperature

Shows the temperature in the casting (all plottypes) and in the mold (only 2D plots).

Temperature is shown AT THE TIME THAT THESIMULATION STOPPED. Normally, this is at the

end of full solidification.

Plot Data:

Solidification Time

Shows the time, in minutes, at which each pointwithin the casting reached FULL

SOLIDIFICATION, i.e., the solidus point.

Plot Data:

Critical Fraction Solid Time

Shows the time, in minutes, at which each pointwithin the casting reached the CRITICAL

FRACTION SOLID point.

The CFS point is the point at which the alloyloses its ability to flow liquid feed metal. This is

usually the best indication for looking atprogressive solidification, to see if any isolatedhot spots formed within the casting while it was

solidifying.

Plot Data:

Temperature Gradient

Shows the Gradient, which is a measure of howmuch temperature was changing during

solidification over a distance in the casting. Unitsare ºC/cm.

Areas of low gradient tend to be “stagnant”solidification, areas with high gradient are usually

solidifying pretty well directionally.

Plot Data:

Cooling Rate

Measures how quickly a casting was coolingduring solidification. Normally, rapid cooling isassociated with “better” materials properties:

Smaller grain size, more dispersed and dissolvedalloying elements, higher strength.

Units are ºC/Minute

Plot Data:

Material Density

A measure of Macroporosity (macro shrinkage) inthe casting. Value ranges from 0 to 1. Lower

values are worse. Usually, the Critical Value isaround 0.99 to 0.995 (values below this indicate

visible shrinkage).

Plot Data:

Niyama Criterion

A measure of Directional Solidification in thecasting. Low values are bad, high values aregood. A value of 0 means lack of directionalsolidification (usually a thermal center in the

casting).

Can be used to identify potential for centerlineshrinkage.

Plot Data:

FCC Criterion

A measure of the potential for DispersedMicroshrinkage (Microporosity) in the casting, or

Secondary Shrinkage in iron castings.

The Critical Value is usually around 40% of thetotal range.

For example, if the range is 0 to 8, the CriticalValue would be around 3.2. Lower values are less

severe, high values are more severe.

Typical Plot Sequence for Simulations:

• Look at various values of Critical FractionSolid to see the sequence of solidification,and to look for isolated hot spots.

• Look at Material Density in the range of 0.99-0.995 to highlight areas of potential shrinkage.

• Look at FCC Criterion at 40% of range, to lookfor tendencies for microshrinkage orsecondary shrinkage.

• Look at Niyama for possibility of centerlineshrink.

ISO-SURFACE PLOTS are fastest and easiest!

Basics of Riser Design

Chvorinov’s Rule:

t = B (V/A)2

t = Time to complete solidification

B = Mold Constant

V = Volume of a section of the casting

A = Surface area of the same section of the casting


(V/A) is referred to as theCasting Modulus

Casting sections with highmodulus solidify last.

Casting sections with lowmodulus solidify first.


Shapes with high Modulus Shapes with low Modulus


DirectionalSolidification

Lowest Modulus Highest Modulus

Increasing Modulus

Using the Riser Design Wizard

1. Import a 3D model of the casting.

2. Select alloy and mold materials.

3. You MAY elect to place gates to take fillinginto account.

4. Run a simulation of the casting with no risers.



7. Select the Riser Design Wizard from the menu.

An example of using the RiserDesign Wizard

Using SOLIDCast, the typicalapproach to process design for a new

casting is to allow the system toanalyze a casting without risers and

determine the best suggested designfor risering.

This is done with the SOLIDCastRiser Design Wizard™.

Here is an example casting model, imported as a 3Dshape from a CAD system.

Using the Wizard approach, we firstperform a simulation of just the

casting, filled through the gates butwith no risers.

The results of this simulation appearas follows:

Casting simulated with no risers

Now, we run the Riser Design Wizard,which takes the results of this

simulation and suggests what risersare required.

We start by telling SOLIDCast to “Design Risers”

SOLIDCast has determined that 3 risers are required for thiscasting

SOLIDCast then shows us each of thefeeding areas within this casting that

have been identified.

Feeding Area 1

Feeding Area 2

Feeding Area 3

Next, SOLIDCast shows us where theoptimum point of attachment for a

riser would be in each of these threeareas.

This point is the spot in each areawhich has the highest Section

Modulus.

Attachment Pointfor Riser 1



Finally, SOLIDCast suggests anappropriate size for each riser. Thiscalculation is based on both SectionModulus (volume/surface area ratios)and required feed metal volume for

each feed area.

Here is the suggested design for Riser 1 (without a sleeve)

And for Riser 2 (with a sleeve).

And finally, for Riser 3 (also with a sleeve).

Now, we add the suggested risers atthe suggested locations to the

SOLIDCast model.

Riser 1 (No sleeve)

Riser 2 (Ins. sleeve)

Riser 3 (Ins. sleeve)

Basics of Gating Design

Acceleration of Gravity:

g = 32.2 ft/sec2

H

V = 2gH

Objects in Free Fall

H

Basics of Gating DesignLiquid Metal in Free Fall

V = 2gH

Basics of Gating DesignFlow of Liquid Metal Through a

Channel (Runner or Gate)

Flow Rate (in3/sec) = Velocity (in/sec) X Area (in2)

Or

Area =Flow Rate

Velocity

Using the Gating DesignWizard

1. Run a simulation of the casting with no risers.



4. Select the Gating Design Wizard from themenu.

The SOLIDCast System also includesa program called the Gating Design

Wizard™.

This function analyzes the castingand alloy selected, calculates weight

of poured metal, suggests anOptimum Fill Time for the casting,and then details sizes of sprues,runners and gates for best filling.

Let’s see how this would work…

First, we specify the“class” of alloy we'repouring (in this case,Aluminum Alloy)

Next, the systemcalculates Pour Weightfor us.

Then, we describe the“Critical” (thinnest)section thickness.

And finally, the systemtells us the Optimum FillTime for this casting (inthis case, about 20 sec.)

The next step is todescribe the sprueheight and the location ofthe gating relative to thecasting.

This allows the system tocalculate an “EffectiveSprue Height” to use forgating calculations.

Now, since we have two sprues,we’ll divide the weight in half foreach sprue and calculate theassociated gating (35 lbs ofmetal will go down each sprue).

The gating ratio (Sprue:Runner:Gate) canbe specified here. The ratio 1:4:4 isrecommended by AFS for most non-pressurized systems.

Dimensions at top and bottom ofthe first sprue are given here.

Dimensions of the runner priorto the first gate, and dimensionsof that gate, are given here.

Dimensions of the next sectionof the runner, and the secondgate, are given here. Thisensures adequate and even flowto both gates.

Now we consider the secondsprue, runner and gate.Dimensions of the second sprueare given here.

And dimensions of the runnerand single gate are given here.

Now, within a few minutes, we havecalculated all of the dimensional data

that we need in order to design thegating for this casting.

Let’s see how this would look on thefinal model…

Sprue: .77 x .77 Top,.553 x .553 Bottom

Sprue: .77 x .77 Top,.553 x .553 Bottom

Runner: 1.5 x .815

Runner: 1.5 x .428

Gate: 1 x .642

Gate: 1 x .611

Runner: 1.5 x .815

Gate: 1.5 x .815

Now, with the process design asprovided by the SOLIDCast RiserDesign Wizard and the SOLIDCast

Gating Design Wizard, we can run asimulation of the casting process

using SOLIDCast to verify the resultsof the design.

Here is a plot of the sequential areas of solidification in thecasting.

We can section this to view internal areas:

In this view the predicted internal porosity is shown:

The casting has been produced with no internal porosity in thissection.

And now we examine the casting with a horizontal sectionshowing progression of solidification:

And the same view showing predicted internal porosity:

Again, there is no visible porosity in this section.

With an “X-Ray” view we can see all internal areas of thecasting at one time, to determine that there is no porosityanywhere within the casting.

The result:

By using the SOLIDCast processdesign tools, we have very easily and

quickly produced a design forproduction of this casting which will

result in a very sound cast part.

Another Example of using theRiser Design and Gating

Design Wizards:

A “quick look” at a new casting.

Casting Design

File: type_c_interim_ref.stl Dated: 04/15/03

Analysis of Feed Areas &Required Risering

The Riser Design Wizard identified (6) distinctfeeding areas within the casting. In the following

images, each area is identified and thecalculated riser size is shown. Calculations are

based on a sand riser (no sleeves).

Area 1: Requires 12” x 20” Riser



Area 4:Requires 18” x24” Riser



Calculation of Optimal Fill Time

Based on an estimate of total poured weight, andCritical Section Thickness (thinnest section of thecasting), the Gating Design Wizard estimates an

optimal fill time for pouring the casting.

The Gating DesignWizard estimates a FillTime of 78 seconds forthis casting

Once number of gates and sprue and runnerlocations are established, the Gating Design

Wizard can be used to calculate proper size forsprues, runners and gates for correct filling of the

casting cavity.

Flow Simulation for Mold Filling

1. Models are generally built the same way you would buildthem for SOLIDCast simulation.

2. Normally we include the entire gating system whensimulating with FLOWCast.

3. Calculate Optimal Fill Time using the SOLIDCast GatingDesign Wizard.

4. For bottom-pour ladles, you can calculate a variable flowrate using the Ladle Calculation Utility, too.

Using FLOWCast

FLOWCast assumes that metal flows inperpendicular to Fill Material surfaces. Therefore,you should avoid “plunging” Fill Material into thetop of a sprue:

Right Wrong

Using FLOWCast

There are two ways to start FLOWCast.

Method 1: Use Mesh… Start FLOWCast

This loads FLOWCast. You then select settingsand start the flow simulation manually.

This is the FLOWCast main screen. Youcan adjust the display from this screen.

To set the steps for saving data, click theFilling tab.

This allows you to set the increment forsaving ALL data (temperature andvelocity) and also just temperature data,which creates a smaller output file.

Here we’ve set the increment for savingtemperature data to 1%. This will allowus to create a video file later on using 100frames or pictures.

FLOWCast allows you to select either aFULL CFD solution or a Quick solution.When the hourglass button is depressed,this indicates you’ve selected the Quicksolution.

To start the flow simulation, click thedouble arrow.

The Status tab shows data sets saved forFULL data, and is also where you go tocreate animation files of temperature,velocity and pressure after thesimulation is complete.

The Anim tab shows sets of savedtemperature data, and is also where yougo to create movies showing temperaturewhen the simulation is complete.

The Pathlines tab allows you to turn onor off the tracks of virtual particles whichare released into the incoming metal atevery 10% increment of fill.

Using FLOWCast

Q: How do I use results of a FLOWCast simulationas the start of a SOLIDCast simulation?

If you’ve run FLOWCast using the Mesh… StartFLOWCast option, just start a simulation usingMesh… Start Simulation and pick SOLIDCast asthe Fill Algorithm:

Using FLOWCast

If you want to run FLOWCast and then SOLIDCastautomatically, use Method 2:

First, select Mesh… StartSimulation

Then specify the FLOWCastAlgorithm (Full or Quick) youwant to use

Ways to Visualize Flow Patterns withFLOWCast

1. Velocity Vectors

2. Trace Particle Paths

Velocity Vectors are plotted onsectional planes cut through themodel. To set up plotting ofVelocity Vectors, we first need toselect Velocity as the item to plot.

Next we select a view or rotate themodel to the desired view.

We can turn off Perspective …

… to get an Orthogonal view.

From the Settings menu we canselect the color for the VelocityVectors…

… the thickness of the vectors…

… and the size of the vectorheads.

To turn on vector plotting, weselect a Cutting Plane (in this casethe X-Z Plane) and ask the systemto Display Veloc Vectors on Plane.

Velocity Vectors show thedirection of flow of metal at everypoint on the cutting plane…

… showing flow streams, vorticesand areas of high and low velocity.

Particle Tracks

Particle tracks shows the pathof simulated particles

released into the incomingstream at specific intervals.

Particle tracks are turned on byselecting the Pathlines tab. Color,thickness and number of trackscan be controlled with theSettings menu.

This shows paths of particlesreleased at the start of filling.

At 20% full…

At 50% full…

And at 80% full. Particle trackscan also be included in movie(AVI) files.

A Third Example of Using theRiser Design and Gating

Design Wizards:

Designing for multi-cavity production

Using SOLIDCast and FLOWCastsoftware, we will develop a design forthe rigging and production of this 356

aluminum alloy casting.

The first step involves consideration ofthe casting geometry, without gates or

risers.

Casting model as furnished bythe foundry.

Casting model as furnished bythe foundry.

Using the Riser Design Wizard inSOLIDCast as a starting point, we

analyze this shape to determine theModulus* of the casting. Modulus is apredictor of the order of solidification

of various parts of the casting, and canbe used to indicate the best

attachment points for gates and risers,as well as appropriate sizes for risers.

*Note: The traditional Modulus used in casting design isdefined as the ratio of Volume:Surface Area. SOLIDCast

uses a Thermal Modulus which is more accurate thantraditional V/SA analysis.

Plot of Modulus values in thiscasting.

Plot of Modulus values in thiscasting.

Point of maximumModulus. This is thelast point to freeze,and the best place toattach a riser.

The Riser Design Wizard can analyzethe patterns of Modulus values within acasting and make recommendations asto how many risers are required, wherethey should be placed, and what size

they should be.

Here’s the Riser Design Wizard’s starting screen.

By analyzing patterns within thecasting, the Wizard tells us that threerisers would be the optimal design.

Next, by using an “X-ray” view of thecasting, we can see where these high-modulus areas are in the casting. Intheory, each of these areas should be

fed by its own riser.

Main feeding areaSecondaryfeeding areas

The next series of views shows thelocation suggested by SOLIDCast as

the best attachment point for the mainriser, considering the point of highest

modulus within the casting.

Now, the Riser Design Wizard is able torecommend riser sizes for each of

these areas. Riser size is determinedby consideration of Modulus (the

Modulus of the riser should be greaterthan the Modulus of the casting) andvolume (the volume of the riser mustbe sufficient to provide feed metal tocompensate for the contraction of the

alloy during liquid cooling andsolidification).

Here, the required riser size is givenas 2” diameter X 5” high. The volumerequirement controls. This is for the

main riser for one casting.

Assuming that we might feed twocastings with a common riser, we can

adjust riser dimensions to provideenough feed metal for two castings.

Doing this, required riser size to feed(2) castings is 2.5” diameter X 6”

high.

Now we can ask the system to size thesmaller, secondary risers, as follows:

Riser 2 is given as 1.5” diameter

X 3” high.

And Riser 3 requires the samedimensions, 1.5” diameter X 3” high.

Next, the Gating Design Wizard cangive us a suggested Optimal Fill Time

and sizes for sprue, runners and gates.

Calculating a Pour Weight for (4)castings per mold, and taking into

account the Critical Wall Thickness of0.217” in the casting, the Gating

Design Wizard suggests an OptimalFill Time of 8.7 seconds.

Here we specify the gatingarrangement and a gating

ratio of 1:2:2

The Wizard tells us we should have asprue that is .897” diameter (we’ve

assumed a round straight spruehere).

And the runner size should be .632square inches.

Using this information, we can create aninitial gating and riser design for

production of this casting in a 4-on mold.

Initial Suggested Design forGates and Risers

What happened to the secondary risers1 and 2?

In our initial design, we will test to seeif the temperature distribution due tofilling through the main riser will beenough to overcome the need forsecondary risers, by encouraging

directional solidification into the largeriser. If not, we’ll add them later… or

we could try chilling those areasinstead.

The next step is to run a simulation ofthis casting, using the initial design.This will involve using FLOWCast tomodel the flow of the liquid into thecasting, and SOLIDCast to model

solidification and shrinkage formation.This will allow us to evaluate this

design and determine whether anyfurther modifications are necessary.

FLOWCast is a flow simulation modulewhich models the filling of the gatingand mold cavity. FLOWCast models

progressive temperature and velocityof the liquid metal.

The following series showsprogressive temperature of the liquid

metal during filling.

FLOWCast can also show flowpathlines, or particle trace lines. Thishelps to visualize the flow of the metaland determine whether any excessive

vortexing or turbulence may beoccurring. This can also be used to

predict the likely end location offoreign particles (oxides or dirt)entrained in the metal stream.

Flow Pathlines

FLOWCast can also show velocity of theliquid metal at any point in the liquid.

FLOWCast can also show pressure ofthe liquid metal at any point in the liquid.

FLOWCast is used to visualize how thegating will function, and how the moldwill fill. Flow-related defects such as

misruns or cold shuts can beidentified. It also provides the most

realistic temperature distribution in thecasting and mold for a subsequent

solidification analysis.

In this case, the flow sequence looksgood. Now let’s progress on to

analysis of the solidification of thecasting.

SOLIDCast is used to predict thecooling and solidification of thecasting after filling, as well as

formation of any shrinkage(macroporosity or microporosity).

Here we see the predicted finaltemperature distribution in thecasting, at the end ofsolidification.

This shows a good temperature gradient fromthe far side of the casting back into the risers.

This image shows the pattern ofsolidification in the castings.

This shows a good pattern of directionalsolidification out of the castings and into therisers.

Prediction of macroporosity(shrinkage) in the castings.

X-Ray View

Prediction of areas of microporosity(dispersed micro-shrinkage) in thecastings.

X-Ray View

Conclusion

By using the gating and risers assuggested by the Gating and Riser

Design Wizards, we were able todesign the process for this casting

very rapidly. By using FLOWCast andSOLIDCast, we were able to verify

through simulation that this designshould produce a sound casting.

Casting Analysis

737305 INSERT

9-April-2004

Step 1:

Casting Model as Imported fromCAD File

Step 2:

Analysis of Thermal Modulus

Step 3:

X-Ray View of Thermal Analysis

For Feeder Locations

As identified automatically by the SOLIDCastRiser Design Wizard.

Feeder Location 1

Feeder Location 2

Feeder Location 3

Feeder Location 4

Step 4:

Calculation of Required FeederSize at Each Location

(In this calculation, we have assumed nosleeves.)

This approach considers Modulus and VolumeRequirement for each Feeder.

Step 5:

Calculation of GatingComponents:

Sprue, Runners and Gates

Calculation of Optimal Fill Time Specification of Gating Parameters

Calculation of Sprue Sizes Calculation of Runner and Gate Sizes

Step 6:

Development of Initial RiggingDesign for Casting Production

Design #1

Filling Simulation: 10% Full



Temperature Distribution at End of Solidification

Progressive Solidification

X-Ray View of Shrinkage (Macroporosity) Prediction

Small Area ofPredicted Shrinkage

Step 6:

Design Iteration #2

Design #2

Two smaller topfeeders




Temperature Distribution at End of Solidification


X-Ray View of Shrinkage (Macroporosity) Prediction

No PredictedShrinkage in Casting

Timing Data

CFD Flow Simulation: 111 Minutes

Solidification Simulation: 13 Minutes

An Example in Cast Iron

The Iron Property Calculator

With Riser Design

First, the STL file is loaded.

This is what the shape looks like.

I select a 4 CE gray iron asthe Casting Alloy. I haveadjusted the pourtemperature to about 70degrees below the 2550Ftemperature you gave me,because we are initiallygoing to simulate the ironalready in the mold and a70F temperature drop is atypical estimate for theloss from filling.

I select silica sand as moldmaterial.

And make sure thatInternal HT Coefficientsare not turned on, and theExternal HT Coefficient isset to about 1.5.

Now we mesh the model with arelatively coarse mesh… 500,000Nodes with 3” of sand all around.

And we start a simulation running.

The simulation should run fairly quickly.

When the simulation is done, we double-click on“Simulation” on the Project Tree, which displays theSimulation Status window. We close this window.

Then we select Simulation… Riser DesignWizard. All we are doing at this point iscalculating the modulus of the casting.

In the Riser Design Wizard, we select “Calculate andDisplay Casting Modulus” and press Next.

Then we select “Plot Iso-Surface” and press Next.

On this window we can see the maximum value ofmodulus, which is 1.215. This is the casting modulus.That’s all we need for the moment, so we cancel this plotand close the Riser Design Wizard.

We also need the casting weight, so we select “Mesh”and “Weights” from the menu.

And we see that the weight of the casting is about 812pounds.

Next we go to the Tools menuand select “Iron PropertyCalculator”.

Here I have assumed a carboncontent of 3.4%, silicon 1.8%and P of 0.02%. We fill in thecasting modulus as 1.215(calculated previously) and forTemperature in the Mold weenter 2480.

Pressing the “Calculate” button,we see that the Shrinkage Timeis 41.88% and the amount ofcontraction is 2.19%.

Next, we press the Riser Designbutton.

This brings up thenew Iron CastingRiser Designwindow. We fill inthe weight of 812 lbs,set the amount ofmold dilation to 1%(for green sand),assume a side sandriser and set the H:Dratio to 1.5.

Now, pressing“Calculate”, we seethe required sandriser size is about8.4D x 12.6H. Alsonote that the NeckModulus is .786.

Here are thedimensions if wehave an InsulatingSleeve.

And for anExothermic Sleeve.

Closing the Iron Casting Riser Designwindow, we now go back to the Simulation…Riser Design Wizard function. Now that weknow the neck modulus, we want to see ifthere is a single feeding area or multiplefeeding areas in this casting, using the neckmodulus as a guide.

In the Riser Design Wizard, again we select “Calculateand Display Casting Modulus” and press Next.

Then we select “Plot Iso-Surface” and press Next.

Now on the plot parameters, we enter the neck moduluswhich is 0.786 into the “Plot This Value” field. Then wepress OK to plot this value.

This plot shows that there is a SINGLE FEEDING ZONEin this casting, based on the neck modulus. This meanswe should use a single riser on this casting.

This is what a sand riser might look like, based on thedimensions as calculated with the Iron Casting RiserDesign program.

Now we want to know what size sprue and gate to designfor this casting. We select Simulation… Gating DesignWizard, select Horizontal Gating, enter an estimatedpouring weight of 1200 lbs., section thickness of 3.2inches and press “Calc. Fill Time”. This gives us acalculated Optimal Fill Time of 53 seconds.

Here we make some assumptionsabout sprue height and specify agating ratio of 4:8:3 (pressurized).

The program tells us that the topsprue diameter should be about3.5” and the bottom diameterabout 2.1”.

Now we design a gate. The bestconfiguration is to gate into the riser,and to keep a 1:5 ratio of H:W on thegate so that the gate freezes quicklyenough. The program calculates agate size of 0.5” x 5.3” for thiscondition.

Adding this simple gating system to themodel, we end up with a system that lookslike this.

What’s left? We might be able toreduce the size of the risers and still

produce a sound casting, thusimproving yield. This can be done by

testing a few smaller riser designs andrunning new simulations… or we coulduse the OPTICast module and have the

system automatically find the “best”riser design which produces a sound

casting while maximizing yield.

How do we know thatoptimum process designs

are actually beingachieved?

The highest quality casting at thelowest cost.

The most efficient way to produce acasting.

What do we mean by“OPTIMUM”?

The current process…

Foundry Engineer

InitialDesign

ProcessSimulation

System

Foundry Engineer

RevisedDesign

Simulation Results

DecideWhat toChange

Acceptable?

NotAcceptable?

Done

A new paradigm…

Foundry Engineer

InitialDesign

ProcessSimulation

System

RevisedDesign

Simulation Results

DecideWhat toChange

Acceptable?

NotAcceptable?

Done OptimizationEngine

OptimizingEngine

Casting ProcessSimulator

Computer Operating System andHardware

The “Layered System” Approach

What is Optimization?

Optimization is a mathematical method for finding the“best” solution to a given problem.

Automates the search for a design solution

Frees the engineer’s time

Provides a more thorough and repeatabledesign process.

Steps Required for Optimization

• Design Variables

• Constraints

• An Objective Function

1) Develop an Initial Design.

2) Define three types of elements:

3) Launch the Optimization

Design Variables

These are elements that are allowed to vary when thecomputer is searching for an optimum process

design.

Examples:

Height and diameter of a feeder (riser)

Size of a feature on the casting

Pouring temperature

Shell preheat temperature

One Type of Design Variable – Geometric Feature Size

Another Type of Design Variable: Initial Temperature

Constraints

A constraint is some aspect of a design thatdetermines whether that design is acceptable or not.

Typical Constraints:

Macroporosity Level

Microporosity Level

Yield Percentage

Minimum Cooling Rate

Minimum Thermal Gradient

The Objective Function

The Objective Function is the single result which youare trying to either maximize or minimize.

Typical Objective Functions:

Maximize Yield Percentage

Minimize Macroporosity Level

Minimize Microporosity Level

Maximize Cooling Rate

Maximize Directional Solidification

The Optimization Process

The Optimization Engine varies each Design Variablewithin the Design Space to create a series of process

models.

Each design is evaluated as to whether it violates anyConstraint.

Each design is then evaluated to determine if theObjective Function has been achieved, through the

use of convergence criteria.

Modify the 3DSimulation

Model

Run a Simulationwith

ExamineResults

WereConstraints

violated?

Was anoptimum

value of theObjectiveFunction

achieved?

Decide on newvalues for Design

Variables

DONE

Yes/No

No/Yes

How OPTICast Works

The Optimization Engine evaluates Response Surfaces.

Requirements of the Modeling System forApplication of Optimization

Must be able to automatically modify geometry

Must be able to handle shape interference as shapesare modified

Must be able to automatically remesh each design

Must be able to process multiple simulations asquickly as possible

Optimization allows us to take aninitial process design and, from that

design, find the OPTIMUM designwhich will result in maximum part

quality and minimum part cost.

Example: Automotivecasting – Current Design

Current RiserDimensions:

92 mm Dia. at P/L

175 mm Overall Height

Simulation of current risershows adequate size and mass

to feed the casting properly.

Sectional view showingsimulation of currentriser feeding

“X-ray” view showingsimulation of currentriser feeding

Question:

Can the weight of the riser bereduced, and yet still provide

adequate feeding to thecasting?

We can answer this questionusing mathematical

optimization.

The OPTICast™ systemcombines the SOLIDCast™casting simulation packagefrom Finite Solutions, Inc.

with HyperOpt® Optimizationfrom Altair Engineering.

In order to performoptimization on this riserdesign, we need to define

three parameters:

• Design Variables

• Constraints

• Objective Function

Design Variables are anyaspects of the design that we

will allow the optimizer tovary during the optimization

run.

Here we have selected the riseras a Design Variable. ItsHeight and Diameter will beallowed to vary independently.

A Constraint is an outputwhich determines whether a

design is acceptable.

Here we set Casting Porosityas a constraint. Porosity is

measured by considering theminimum local material

density in the casting. Theconstraint value is set to 1.0,which indicates no casting

porosity allowed.

The Objective Function is asimulation output which

measures the end result weare trying to achieve.

For purposes of this optimization, wedefine a yield number such that

Yield =

The Objective Function is themaximization of this number, which

results in minimum riser weight.

Casting Weight

Casting + Riser Weight


The Optimization Engine varies each Design Variablewithin the Design Space to create a series of process

models.

Each design is evaluated as to whether it violates anyConstraint.

Each design is then evaluated to determine if theObjective Function has been achieved, through the

use of convergence criteria.

Modify the 3DSimulation

Model

Run a Simulationwith

ExamineResults

WereConstraints

violated?

Was anoptimum


achieved?


Variables

DONE

Yes/No

No/Yes

How OPTICast Works

Optimization Results

The riser design optimization wascomplete after 26 simulations. These

were run completely automatically.

Total processing time was 2 hr. 56 min.on a 1.0 GHz PC.

This chart shows the progressive value of the Yield functionover 26 simulations. Its value started at 0.60 and ended at 0.72.

This chart shows simulated porosity in the casting. A value of1.0 represents a completely sound casting. Final value of 0.9995

is within allowable limits.

A plot of the vertical scale of the riser. The final riser design is13.1% taller than the current riser.

A plot of the horizontal scale (diameter) of the riser. The finalriser design is smaller (72%) in diameter than the current riser.

Comparison of current riser vs.optimized riser design

92 mm Dia. X 175mm Height.

66 mm Dia. X 198mm Height.

Simulation of the optimizedriser design shows adequate

size and mass to feed thecasting properly.

Sectional view showingsimulation of optimizedriser feeding

“X-ray” view showingsimulation of optimizedriser feeding

Optimized riser shownwith gating

Weight Reduction

Current Riser Weight: 16.03 lbs.

Optimized Riser Weight: 9.39 lbs.

Weight Reduction/Riser: 6.64 lbs.

Weight Reduction/Mold (8-on): 53.1 lbs.

Conclusion of Optimization:

• Pour weight per mold can be reduced by53.1 pounds through redesign of the riser byoptimization

• At current production volumes, this results ina saving of more than $US 100,000 per year(1800 tons of metal saved annually)

• Annual Energy Savings: 1,980,000 KWH

Process Design Optimization for:

Stainless Steel Investment Casting

Pour Temperature: 2925ºF

Shell Preheat: 1800ºF

Shell Thickness: 0.5”

Alloy: CF8M

In this case, we start with Design Iteration#7, which produced a shrink-free casting.

Wedge shapes, approx. 1.5” wide

This designused two smallwedge shapesunder the gatesto help feedmetal into theheavy section ofthe casting.

Here’s the gatedesign that willbe optimized byusing OPTICast.

The first step is to select Design Variables.These are features of the gating that are

allowed to vary in size.

Here we’ve selectedthe horizontal feederbar as DesignVariable #1.

The pour cup isselected as DesignVariable #2.

We’re specifiedthat ONLY thehorizontaldimensions of thepour cup canvary; its heightstays constant.

The gate is selectedas Design Variable#3.

The gate’s heightis held constant,but its width isallowed to vary.

The other gate is“linked” to thefirst gate, whichmeans that thetwo gates willalways be thesame shape.

Now we need to apply a Constraint. This isan OUTPUT VALUE from each simulationwhich determines whether the results are

acceptable or not.

In this case, our constraint is that thecasting must be “free of shrinkage”. Anydesign which results in shrinkage in the

casting will be discarded.

We measureshrinkage asMaterialDensity. Avalue of 1means aperfectly soundcasting, so weset theConstraintValue to 1.

Finally, we select an Objective Function.This is an OUTPUT VALUE that we aretrying to either maximize of minimize.

In this case, our objective function will be to“Maximize the Yield”. This means that themaximum yield (i.e., the minimum amountof poured metal weight) which produces a

shrink-free casting will be found.

This is done just byselecting YieldMaximization from a listof Objective Functions.

At this point, we start the optimizationrunning. This is a TOTALLY AUTOMATIC

process. OPTICast will run a series ofsimulations, varying the gate design untilthe yield is maximized and the casting is

shrink-free.

This process can be illustrated as follows:

Modify the 3DComputer

Model

Run a Simulation

ExtractResults

WereConstraints

violated?

Was anoptimum


achieved?


Variables

DONE

Yes/No

No/Yes


In effect, the computer is redesigning thisgating system ON ITS OWN, using the

rules and guidelines that we set up.

Now let’s look at the Results…

Here is the Yield foreach of 50simulation runs.

The yield increasedfrom 38% to 53%.

This chart showscasting soundnessfor each of 50simulation runs.

A value of 1.0means a soundcasting (no shrink).

This shows thehorizontal scalefactor for the feeder.

The optimizedfeeder is 82% of itsoriginal size(horizontally).

This chart showsthe vertical scalefactor for the feeder.

The optimizedfeeder is 83% of itsoriginal size(vertically).

This shows thehorizontal scalefactor for the pourcup.

The optimized pourcup is 42% of itsoriginal size(horizontally).

And, finally,thischart shows thehorizontal scalefactor for the gates.

The optimized gatesare 120% of theiroriginal size(horizontally).

So, how does the optimized designcompare with the original gating design?

Original Gating Optimized Gating

SolidificationPattern

Hot Spots No HotSpots


ShrinkagePrediction

Shrinkage inCasting

NoShrinkage in

Casting


123 Lb. Pour Weight 88.3 Lb. Pour Weight

Final Results

1. Pour weight reduced 34.7 Lbs.per casting

2. Shrinkage eliminated fromcasting

3. Annual savings: $17,000

4. Energy savings: 7,000 KWH/yr

Utilities Menu

The Utilities Menu gives access to a wide variety of functions.

Convert ASCII STL to Binary

Allows you to convert an ASCII STL file to aBinary STL file so that it can be loaded into

SOLIDCast as a model shape.

Create Shell Around STL Shape

This program accepts an STL file as input, andcreates a new STL file as output which

represents a shell of a constant thickness aroundthe first STL file. This shell shape can then bebrought into the SOLIDCast model as a model

shape.

Custom Formula

Allows you to create a customized formula forcalculation and plotting from SOLIDCast results. Forexample, in aluminum alloys a formula for Dendrite

Arm Spacing (DAS) in microns is:

DAS = 35 (ts-tl) 0.333

and in Steel a formula is:

DAS = 100 (ts-tl) 0.41

Both of these formulae can be entered using CustomFormula, and plotted using Custom-High.

Data Capture (Temperature)

Allows you to capture time/temperature data from anunlimited number of points within a model.

Early Fill Tilt Pour

This utility allows most of the metal in a tilt pourFLOWCast simulation to enter the mold at a givenpercent of tilt. For example, if the mold tilts through

90 degrees during filling, and the user specifies 50%as the completion point, then most of the liquid metalwill have entered the mold during the first 45 degrees

of tilting.

Filter Shape

This utility helps you to create an STL file consistingof a rectangular block with cylindrical holes. This

object, when added to a model and given ceramicthermal properties, can be used to simulate a filter.

HTC Calculator

This utility helps to calculate the appropriate HeatTransfer Coefficients to use for various situations.

Calculations are included for:

• Air and water cooling channels

•Natural and forced convection

•Radiation

•Mold coatings

Iron Property Calculator

Allows you to calculate % contraction/expansion andCFS point for cast iron, based on the German Iron

Society VDG Nomograms and the charts developedby Karsay. This utility also performs risering

calculations for cast irons, as demonstrated in thefollowing slides.

Design of risers for Grey Iron andDuctile Iron castings involves one

primary consideration above all else:

Control of Expansion Pressure

This means allowing riser necks toremain open long enough to feed

liquid shrinkage, but ensuring thatthey freeze in time to pressurize thecasting during expansion and avoid

formation of shrinkage porosity.

The solidification of iron castings(ductile, or nodular, iron and gray

iron) is unique among cast metals,due to the precipitation of graphite asthe iron solidifies. The graphite takesvarious forms depending on the typeof iron. For example, in ductile iron

(nodular iron), the graphite isprimarily spheroidal, which gives theiron its characteristic ductility since

the spheroids tend to reducelocalized stresses under load.

While in gray iron, the graphite tendsto be in the shape of flakes, which

results in gray iron’s greatcompressive stress but relatively low

tensile stress.

And in compacted graphite iron, thestructure and properties tend to be

somewhat intermediate.

The precipitation of graphite duringsolidification causes some expansion tooccur, because the graphite is much less

dense than the surrounding iron. Therefore,we have several forces at work. The liquid

iron tends to contract as do almost allliquids when cooled. During solidification,

the austenitic iron also contracts as do mostmetals upon solidification. However, the

precipitating graphite causes an expansionpressure which can be used to our

advantage if the feeding system is properlydesigned.

No matter which type of cast iron weare pouring, the secret of good

design is to provide a feeding systemto compensate for the liquidshrinkage and then allow the

expansion (due to carbonprecipitation) to provide enough

pressure to produce a sound casting.

There are some differences inexpansion pressure between ductileiron and grey iron as shown in the

following chart:

Regardless of the type of iron castingwe are designing, there are a set of

basic procedures that can befollowed which will help us to ensure

high-quality, sound iron castings,using the SOLIDCast Simulation

System. These procedures will helpto minimize the number of sample

castings required, reduce lead timesto get into production, and result in

consistent-quality castings which willmake our customers happy and our

foundry more profitable.

Step 1

To begin analyzing a casting inSOLIDCast for the purpose of riser

design, we initially run a simulation ofjust the casting, surrounded by mold

material, without gates or risers.

Step 2

We then run the SOLIDCast RiserDesign Wizard and select "Calculate

and Display Casting Modulus" to findout the maximum modulus of the

casting.

Step 3

We next run the SOLIDCast Cast IronProperty Calculator program to

calculate the Shrinkage Time (ST) andnet Percent Expansion (+) or

Contraction (-) of the iron based onchemistry, modulus and temperature

in the mold. This is based on theVDG Nomograms and Karsay charts

for iron properties.

Step 4

This gives us the net expansion ofthe iron considering only the metal,

without taking into account thedilation of the mold. For actualfeeding requirement, we must

estimate mold dilation which mightvary from less than 0.5% for

chemically-bonded molds to morethan 2% for loose green sand molds.

Step 5

Rule: Recommended practice wouldbe to use a "hot" riser, i.e., to gate

into the riser if using a side riser sothat the amount of heat in the riser,and its ability to provide feed metal,is maximized. For top risers, since it

is difficult to gate into these, wewould typically recommend a sleeve(either exothermic or insulating) to

retain the heat.

Step 6

The proportion of liquid metal that can besupplied by a riser can be estimated by

knowing its condition. For example, a hotside riser can typically provide about 20% ofits metal for feeding, while a typical cold riser

might provide around 14% of its metal. Asleeved riser can provide anywhere from 33%

to 35% depending on its condition.Exothermic mini-risers have been known toprovide up to 70% of their metal for feeding.

Step 7

The formula relating the available volume ofmetal in a riser to the volume of the casting

can be expressed as:

Vf = Vc * Sx

(Where Vf = Riser Volume, Vc = Casting Volume, S = FeedingRequirement (including Mold Dilation), and x = Proportion of Liquid

Metal Removed from Riser)

and from this the diameter of the riser can becalculated if an assumption of riser

Height:Diameter is made.

______

Step 8

The riser neck should be sized so that its modulusguarantees that it will freeze at the point that the liquidshrinkage is done and any subsequent expansion will

be controlled and contained within the casting toprevent shrinkage porosity formation. This can be

accomplished by using the following formula:

Mn = ST/100 * Mc

Where Mn = Modulus of the Neck, ST = ShrinkageTime, and Mc = Modulus of the Casting.

Step 9

Also, in order for the riser to provide sufficient liquidmelt during the shrinkage period, its modulus shouldbe 20% greater than the neck modulus, which means

the riser size should satisfy the equation:

Mr = 1.2 Mn

or Mr = 1.2 ST/100 Mc

So that if the riser is sized to satisfy the liquid feedingrequirement but it does not satisfy this modulusrequirement, its size must be increased to satisfy thismodulus requirement.

Step 10

If the riser is close enough to the casting sothat mold heatup between the casting and

riser can be taken into account, the requiredmodulus of the neck can be reduced by

multiplying by a factor of 0.6.Rule: In order to be considered a short neck,the distance between the casting and the risershould be less than the minimum dimension

of the riser neck.

Riser Neck

Step 11

How many risers are required for a casting?Rule: Only one riser should be used for each

feed zone within a casting. Feed zones can bevisualized by plotting the neck modulus, alsocalled the Transfer Modulus. If more than one

riser is used for a single feeding zone, inalmost all cases only one of the risers will

pipe and the other riser(s) will not pipe but willcreate a thermal hot spot underneath at which

some shrinkage porosity will be likely toappear.

Two risers, only onehas piped.

In every case, eachcasting has tworisers and only onehas piped.

Two risers, onecasting.

This riser piped.

This riser piped.

Step 12

SOLIDCast uses the THERMAL MODULUS tocalculate the location and extent of feedingzones within the casting. This is superior tothe traditional measure of Volume:SurfaceArea Ratio, as it is able to take into accountheat saturation of mold and core pockets aswell as heat extraction by chills and, ifdesired, temperature distribution due to filling.

Step 13

The SOLIDCast Cast Iron Riser DesignProgram assumes that side risers arecylindrical with a hemispherical bottom, whiletop risers are cylindrical in shape.

Rule: The tops of the risers should be abovethe highest point of the casting for gray andductile iron casting, by at least the minimumsection thickness.

Step 14

Gating should be designed to freeze relativelyquickly after the liquid metal has filled themold cavity. In general, this means that thegate attachment to the casting should have a5:1 ratio of width to height to ensure relativelyquick freezing so that expansion pressure canbe contained. Remember, Control ofExpansion Pressure is our ultimate goal infeeding cast iron.

“A”

t = √A/5

t = √A/3

All of these calculations can be performedquickly and easily in

As an example, consider the task of designinga feeding system for the following ductile iron

casting.

This is the basic casting shape as importedfrom a CAD system in SOLIDCast.

Ductile Iron is selected asthe Casting Material fromthe SOLIDCast database.

The casting is meshed withno risers or gates, so that a“thermal” simulation can berun for calculation of theModulus of the casting.

Once the thermal simulationis complete, the SOLIDCastRiser Design Wizard isselected…

… and the user instructs theWizard to calculate anddisplay the CastingModulus.

The Iso-Surface Plot isselected…

… and from the Iso-SurfacePlot Menu, we can read thatthe maximum Modulus ofthis casting is about 0.469in. At this point, this is allthe information we needfrom the Wizard, so we canjust press Cancel to avoidmaking the plot at this time.

Another item of informationwe’ll need is the weight ofthe casting. This can beeasily obtained by selectingMesh… Weights from themain menu. Here we cansee that the casting weighs18.953 lb.

Now we are ready to calculate the propertiesof the iron, and the required riser size.

From the main menu, weselect Tools… Iron PropertyCalculator.

Here we enter theCarbon, Silicon andPhosphorus contentof the iron.

Here we enter thecasting Modulus aspreviously calculatedby the Wizard.

And here we enter anestimate of thetemperature of themetal in the mold.

Clicking the Calculate Iron Properties button causes the system todisplay the Shrinkage Time (ST) in terms of % Solid, and the netamount of Expansion (+) or Contraction (-) which occurs up to thatShrinkage Time. This is the quality of the iron without consideringmold dilation.

Now that we have the properties of the ironcalculated, we can design a riser for this

casting.

First, we enter thecasting weight aspreviously calculatedby the system in theMesh menu.

Next, we select theexpected amount ofmold dilation. This canbe anywhere from lessthan 0.5% for a veryrigid mold to more than2% for a loose greensand mold. Herewe’ve selected 1% fora well-made sandmold.

The next item to selectis sleeve type. Youcan select either asand riser (no sleeve),an insulating riser,exothermic orexothermic mini-riser.You can also selectwhether the casting isgated through the riser.The proportion of liquidmetal removed fromthe riser isautomatically adjusted.

Next we select the ratioof Height to Diameterthat we want to use forthe riser design.

Finally, we have theoption to select either aTop or Side Riser.Here we have selecteda Side Riser.

Now, pressing the Calculatebutton will display the requiredriser and neck size, as well asthe Modulus of the neck andthe riser. Note that the NeckModulus is also referred to asthe Transfer Modulus and canbe used to indicate how manyfeeding zones (and now manyrequired risers) there are forthis casting.

Notice that by selecting theShort Neck option andrepressing the Calculatebutton, we can calculate aneck size for a riser which isvery close to the casting(closer than the minimumdimension of the neck).

Now by plotting the Transfer Modulus in an X-RayView (Iso-Surface Plot) we can see that the entirecasting is one feeding zone, so only one riser isrequired for this casting.

Another image of the Transfer Modulus, usingCastPic plotting, also shows one zone which meansone riser is required for this casting.

A more traditional Modulus calculation usingVolume/Surface Area Ratio would have indicated twoseparate feeding areas, one in the central hub andone around the outer rim as shown here. Why isthere a difference?

This cross-sectional view through the casting and mold showstemperature. You can see that the mold material becomes saturatedwith heat in the “pocket” areas between the inner hub and the outer rim,which keeps the thinner sections hot. This effect would not be capturedby performing the old-fashioned Volume/Surface Area Moduluscalculations, but is automatically taken into account when performingthe Thermal Modulus function within SOLIDCast, because thermaleffects in the mold are simulated.

Heat Saturation

Now that we have the riser and neck dimensioned, we also need todimension the sprue, runner and gate, as well as estimate a fill time.The SOLIDCast Gating Wizard calculates an Optimal Fill Time of about13 seconds for this casting (assuming a single casting).

And by describing the geometry of our proposedgating system…

The Wizard calculates for us a sprue diameter of about 0.575 in.

And an inlet gate of about 0.23 in. x 1.13 in., which shouldensure that the gate freezes quickly for control of expansionpressure.

Now we can use all of the calculateddimensions to create a simple system for

gating and feeding this casting, which wouldappear as follows:

The complete model: Casting, Neck, Riser,Gate and Sprue

We use the results of the Cast Iron CalculationUtility Program to adjust the shrinkage curveparameters for the exact conditions of thisiron chemistry, temperature and modulus

value.

Shrinkage Time of 63%, amountof shrinkage = -1.1% minus MoldDilation of 1% for a total shrinkageof -2.1%.

Add expansion of approximately0.5% per 10% solidification.

Set CFS Pointapprox. 5% to theright of the ST Point

Using FLOWCast, we first perform a fillingsimulation of the casting, pouring metal downthe sprue, through the gate and riser and into

the casting cavity.

Finally, we use SOLIDCast to perform asimulation of the solidification of the castingand to predict the soundness of the final part.


Shrinkage Prediction

Shrinkage Prediction: X-Ray View

The Final Result

A sound casting, correctly designed using theSOLIDCast Riser and Gating Design tools, and

verified using SOLIDCast and FLOWCastsimulation.

www.finitesolutions.com

Ladle Calculations

Allows you to calculate capacities, flow rates and filltimes from a given ladle. This utility also interfaces

to FLOWCast and allows fill simulation using variableflow rates from a ladle.

Mask Riser Density

Removes Material Density data from Riser Materialareas so that you can see Material Density

indications ONLY within the casting.

Plot SOLIDCast Fill Times

Allows you to plot fill times as calculated using theSOLIDCast (not FLOWCast) fill algorithm.

Project Viewer

Allows you to select any model, mesh or simulationin a project and display summary information aboutthat item. For example, you can see exactly how a

model was meshed for simulation, how many shapesare in a model, how long a SOLIDCast simulation

took to run, and numerous other items of data.

QuickPlot

Lets you change the plot display quickly and easily. You canchange the view, resolution and display method. You can also

re-plot very quickly, to create a sort of animation.

Reduce STL File Size

This utility can be used to reduce the number oftriangles, and thus the file size, of an STL file for

easier loading and display in SOLIDCast.

Reset Simulation Stop Point

This utility is used to change the end point of a simulation inSOLIDCast. For example, you can initially run a simulation untilthe casting is solid, and later use the utility to change the end

point when all metal is solid, or when the casting drops below aminimum temperature.

Riser STL Shape

This utility is used to create an STL file for a riser ofgiven size and shape. The STL file can then be

loaded into an existing model in SOLIDCast.

Scale Model Size

This utility can be used to scale the size of aSOLIDCast model up or down (larger or smaller) by a

given scale factor.

Simulation Image Control

Allows you to adjust the view shown as a simulationruns. You can change the angle of the display, the

resolution of the picture and how the solidifyingnodes are displayed.

Simulation Parameters

This utility is used to set several simulation parametersthat in previous versions of SOLIDCast had to be set by

creating and editing text files in the installation folder.These files are still in use and can be adjusted by the

user, but this utility simplifies their use.

SOLIDCast Settings System Info

This utility creates a display and a text file whichgives System Information about your computer andyour installation of SOLIDCast. This can be helpful

to Finite Solutions in diagnosing problems oranswering specific questions.

Solidification Time Gradient Calc

This utility calculates and places solidification timegradient calculations from a simulation into the

Custom function so that they can be plotted. TheSolidification Time Gradient has shown promise as apredictor of areas in a casting prone to hot tearing.

Split Files for Emailing

This utility is used to split large files into pieces sothat they can be emailed (or placed onto media) andis also used to recombine the pieces. Many emailsystems still have limits on the size of attachments,

which in some cases may be as small as 2MB.Video files created by SOLIDCast or FLOWCast will

often be larger than this. The File Splitter UtilityProgram allows you to split these large files into

pieces which can be emailed to another person andthen recombined on the other end.

STL From Model

This utility allows you to create a single STL file of aSOLIDCast model, no matter how many shapes were

used to build the model.

STL Slice

This utility is used to create a 2D slice at a givenpoint through a binary STL file. The slice can be inthe XY, XZ or YZ orthogonal planes. The output 2Ddata can be either DXF format, or in AFSCad format.This is often useful for establishing exact dimensions

or locations of features on STL shapes.

STL of Intersecting Cylinders

This is a special-purpose utility which creates an STLfile representing an intersection of two cylinders with

a fillet radius around the intersection, like this:

Two Stage Pour

This utility is used to set up a file that can be used byFLOWCast for a two stage pour process. For

example, you could do the first 90% of filling from thesprue, pause for a number of seconds, then finishfilling by pouring hot metal into the top of a riser.

For More Information:

Contact

Dave Schmidt: [email protected]

262 644 0785

Or

Larry Smiley: [email protected]

513 737 7300

Documents

Training Overview SolidCast