Study of cutting tools & jig fixture

VIVEKANAND INSTITUTE OF TECHNOLGY AND

SCIENCE(gzb)

STUDY OF CUTTING TOOLS & JIGS FIXTURE

A Project onStudy of Cutting Tools and Jigs Fixture

Submitted for partial fulfillment of award of BACHELOR OF TECHNOLOGY Degree

InMECHANICAL ENGINEERING

By ANUJ KUMAR ALOK SHARMA DEVVRAT SINGH S.M ARSHIL ZAIDI VIVEKANAND INSTITUTE OF TECHNOLOGY AND

SCIENCE,GHAZIABAD UTTAR PRADESH TECHNICAL UNIVERSITY,LUCKNOW

CANDIDATES DECLARATION

We hereby the declare the work being presented in this report entitled ” STUDY OF CUTTING TOOLS AND JIG FIXTURE” is an authentic record of our own work carried out under the supervision of

Mr. “SUBHANKAR KARMAKAR” The matter embodies in this report has not been

submitted by us for the award of any other degree. Name of students ANUJ KUMAR ALOK SHARMA DEVVRAT SINGH S.M ARSHILZAIDI

CONTENTS

1. INTRODUCTION2. TOOL DESIGN METHOD3. DESIRABLE PROPERTIES OF TOOLING MATERIAL4. TOOLING MATERIAL AND HEAT TREATMENT5. SELECTION OF TOOLING MATERIAL6. TOOL GEOMETRY7. CHIPS FORMATION8. TYPE OF CHIPS9. TOOL FAILURE AND TOOL CUTTING LIFE10. EFFECT OF DIFFERENT PARAMETERS ON TOOL

LIFE11. IMPORTANCE OF JIG FIXTURE12. MANUFACTURING OF HAND VICE13. CONCLUSION

1.INTRODUCTION

This project deals with “STUDY OF CUTTING TOOLS AND JIGS FIXTURE” with an aim of increasing the tool life. Various factors play an important role in deciding the tool life such as Geometry of tools, tool material, machining operations, types of coolant used and cutting environment etc.

This project describes the tool design procedures, various tool

materials, selection of appropriate tool for machining operations and explains the reasons for tool failure. It also describes the factors for increasing the tool life.

This project also completely explains the various types of “JIGS

AND FIXTURES” how they are manufactured, principle of location, their specifications & their importance.

The project also includes manufacturing of “HAND VICE”.

2.TOOL DESIGN METHOD

1.Statement of the problem Why the tool is needed? What are the required capabilities of

the tool The type of machine the tool must

be used on The number of the part to be

produced Other pertinent information

concerning the part.


2.The need analysis Will the tool used by the skilled or

unskilled operators? How many parts can be held on the tool? What are the hole-location tolerances on

the part? What provisions are to be made for

coolant Is the cutting force heavy or light? Etc.


3.Research and the ideation(sketches)

Dimension of the part to be held or produced

Kind of the material from which the part is made

The tolerance of the part Dimensions of the machine Limitations of the machine Amount of the tonnage to blank the

part.


4. Tentative design solutions

5.The Finished Design

3.DESIRABLE PROPERTIES OF TOOLING MATERIAL

Strength:Plasticity:Elasticity and stiffness:Elastic limit: Toughness:Hardness:Machinability:Endurance limit:Cost:

4.TOOLING MATERIALS

High carbon steel High speed steel(HSS) Coated high speed steel Cast alloy Cemented carbides Non-Tungsten Cemented Carbides Ceramics (Cemented oxides) Kyon Sialon(Si-Al-O-N) Boron Nitride Diamond Polycrystalline Diamond (PCD) and Solid Film

Diamond (SFD)

4.HEAT TREATMENT

Normalizing: Annealing: Spheroidizing: Hardenability: Stress relieving: Stabilizing: Hardening: Pack hardening: Quenching: Tempering: Double tempering: Decarburization:

5.SELECTION OF TOOLING MATERIAL

Single carbide steel-Machining grey cast iron,brass bronze etc

Composite carbide -Machining Steel


Cemented Carbide


Cemented carbide

6.TOOL GEOMETRY

6.TOOL GEOMETRY

6.TOOL GEOMETRY

6.TOOL GEOMETRY

MILLING CUTTER

7.Chip Formation

All machining processes involve formation of chips by deforming the work material on the surface of the job with the help of the cutting tool.

7.Chip Formation

8.TYPE of CHIPS

(a) tightly curled chip; (b) chip hits workpiece and breaks; (c)continuous chip moving away from workpiece; and (d) chip hits tool shank and breaks off.

8.TYPE of CHIPS

Continuous chips

During the cutting of ductile materials like low carbon steel, copper, brass etc., a continuous ribbon type chip is produced. The pressure of the tool makes the material ahead of the cutting edge deform plastically.

8.TYPE of CHIPS

Continuous chips with built up edge

Continuous chips with built up edge

The temperature is high at the interface between the chip and the tool during the cutting. Also, the work material slides under heavy pressure on the rake face before being transformed into a free chip. In these conditions, some portion of the chip may stick to the rake face of the tool. Because of such a close contact, it discharges its heat to the tool and attracts more of the deforming work material and thus the size of “built up edge” goes on increasing and breaks up after a critical stage.

8.TYPE of CHIPS

Discontinuous chips

These chips are produced during the cutting of brittle material like cast iron, and brasses. Even a slight plastic deformation produced by a small advance of the cutting edge into the job leads to a crack formation in the deforming zone.

9. TOOL FAILURE MECHANISM OF TOOL WEAR1. Adhesion

2. Abrasion

9. TOOL FAILURE MECHANISM OF TOOL WEAR 3. Diffusion

4. Oxidation

9. TOOL FAILURE SOME TOOL FAILURE;1.Flank wear- VB=0.3mm; VBmax=0.6mm.2. Fracture failure.3. Temperature failure4. Gradual wear5. Crater wear- KT = 0.06 + 0.3f, where f is the feed per revolutions6. Plastic Deformation7. 2 Mechanical Breakage

9. TOOL FAILURE

9. TOOL CUTTING LIFE

Taylor’s Empirical Equation:

VT n =CWhere, T = tool life time; usually in minutesV = cutting velocity, m/minC = constant; the cutting velocity for 1 minute of elapsed time before reaching the wear limit of the tooln = constant which is considered a characteristic of the tool material, called tool life index.

Typical Tool Life Exponential Graph

9. TOOL CUTTING LIFE

Modified Taylor’s Equation

This incorporates the feed rate and depth of cut having their own index X and Y where the indexes are obtained experimentally. Typically from machining practices these values can be taken as: n=0.15, x=0.15, and y=0.6 (typical values)

VTndxfy = CThe above equation may be rewritten for determining the time as shown:

T=C1/nV-1/nD-x/nf-y/n

9.CUTTING LIFE

Optimum Cutting Speed

10.EFFECT OF DIFFERENT PARAMETERS ON TOOL LIFE

Effect of Varying Rake Angle

10. EFFECT OF DIFFERENT PARAMETERS ON TOOL LIFE

Influence of Feed Rate on T.L


Influence of Tool Shape on Cutting Speed and Tool Life


Influence of speed and feed on the economics of MRR


Relationship between the specific wear rate and tool temperature

11.IMPORTANCE OF JIGS & FIXTURES

To hold the Work Piece To guide the tool (jigs) Protects the tool from accidental

failure Better productivity Automates the machine tools Ensures machining accuracy Less skilled labor can be used

12.Manufacturing of Hand vice

The manufacturing of hand vice is done with an aim of practically examining all the factors involved in various machining operations, that we have studied in our project. All the factors were carefully studied with an approach to increase the tool life for e.g tool geometry, tool material, temperature, cutting fluid, and proper use of jigs & fixtures etc.

11.CONCLUSION Parameter Influence and interrelationship

Cutting speed, depth of cut , feed Rate , cutting fluids.Tool angles

Continuous chip

Built-up-edge chip

Discontinuous chip

Temperature rise.

Tool wear

Machinability

Forces power, temperature rise, tool life, type of chips, surface finish.influence on chip flow direction; resistance to tool chipping.

Good surface finish ; steady cutting forces ; undesirable in automated machinery.Poor surface finish , thin stable edge can product tool surface.Desirable for ease of chip disposal ; fluctuating cutting forces ; can affect surface finish and cause vibration and chatters.

Influences surface finish , dimensional accuracy, temperature rise, forces and power.Influences surface finish , dimensional accuracy , temperature rise , forces and power.Related to tool life , surface finish , forces and power

11. CONCLUSION

Parameter Influence and interrelationship

Selection of machining process

Selection of tool material Cutting environment

Selection of proper jigs and fixture

Accuracy of machine

Vibration in machine

Right machining process minimize the tool wear ,& gives better tool life.

Selection of tooling material is most important factor. Tool material always should have higher strength then the material to be cut.

Tool life is also depend upon the right jigs/fixture is used. They minimize the accidental tool failure & gives the direction to tool.

Accurate machine have low tool wear rate.

Vibration in machine increase the tool wear.

11. CONCLUSIONParameter Influence and interrelationship

Mechanical properties of tool material

chemical properties of tool material

Selection of cutting fluid

Proper heat treatment

Coating Material

Skill of workers

Tool life is directly depend upon the mechanical properties of tool material

Oxidation decrease the tool life

A proper cutting fluid can increase the tool life uptu 20%

A heat treated tool can with stand higher temp.& have longer tool lifeA proper Coated material can increase the tool life uptu 300%Skill worker have better knowledge of cutting process & machine operation


Proper Methods of Applying Cutting Fluids


Proper heat treatment

Coating Material

Skill of workers

A heat treated tool can with stand higher temp.& have longer tool lifeA proper Coated material can increase the tool life uptu 300%Skill worker have better knowledge of cutting process & machine operation

Thank you

Education

Study of cutting tools & jig fixture