3D-printing

a disruptive technology

challenging creativity

thinking outside the box

Prof. dr.ir. Jan Van Humbeeck

3D Printing or

Additive Manufacturing

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Additive Manufacturing (AM)

= group of production techniques in which parts are made

• from 3D model data

• by joining materials,

• usually layer upon layer ,

as opposed to the traditional subtractive or deformation based manufacturing.

(from ASTM F42 [1])

[1] ASTM international Committee F42

Hype vs Reality: Gartner Hype Cycle

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www.gartner.com

20122015for 3D

How to start?• Select a 3D printing technology and the appropriate material to be

printed.

• The 3D-printer needs to get instructions from a com puter file

• CAD (Computer Aided Design)-file contains the requested part

o By 3D modeling

o By a model created by a 3D scanner

• Software slices the design in horizontal layers with a thickness equal to the layer to be deposited.

• Other software steers the 3D-printer along the lin es seen in the sliced surface.

• Material is deposited copying the sliced surface

• A next layer is deposited

Additive Manufacturing

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[2] Rapid Manufacturing Association.

[2]

Additive Manufacturing

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• From product design to manufacturing

3D model Slicing Process parameters

Manufacturing

Overview of Additive Manufacturing techniques

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Laser parameters

Material parameters

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Scanning parameters

Fused deposition modelling, using polymeric filaments

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Stereolithografie by photopolymerisation of a liquid

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Principle of laser cladding

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In stead of a laser, an arc can be used as well:WAAM: W ire Arc Additive Manuafturing,

1925: Baker patented “The use of an electric arc as a heat sour ce to generate3D objects depositing molten metal in superimposed laye rs”.

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Electron beam melting (EBM)

Schematic overview of the SLM process

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Selective Laser Melting

What can be printed?• Industrial devices

• Medical devices

• Bioprinting

• Food

• Clothing and Fashion

• Buildings

• Everything?

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Industrial devices

• New designs of complex parts using less material• Production of (spare) parts where and when it is

needed through local production sites• To make goods much faster, more economically

(Faster time to market)• No big store houses required• Faster prototyping• Allows testing of new materials (polymers, metallic

alloys, ceramics)

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Additive Manufacturing• starting material:

powder, wire, sheet, (droplets of) liquid …

• layout and layer creation technique: laser or electron beam, powder bed or nozzle, …

• binding mechanism: sintering, liquid phase sintering, full melting, photo-polymerization, …

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AM materials

stainless steels316L 1.440417-4 1.454215-5 1.4540

titanium and titanium alloysTi commercially pure grade 1Ti commercially pure grade 2Ti6Al4V grade 5Ti6Al4V ELI grade 23NiTi (nitinol)

cobalt chromium alloysCoCrMo ASTM F75CoCrMoW

otherTa (tantalum)

Polymeric materials:- ABS-rubber- PLA- PA- PEEK

Ev�

�.�.�

E: energy density, P: laser power,v: scanning speed, h: hatch spacing,t: layer thickness

Important Process Parameters

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Unique process conditions

Unique Microstructure

High energy density input (J/m³s)

+ large heat sink(volume @Tlow)

� High T, dT/dx and dT/dt

Small additionstrack after track layer after layer

[13] [14]

[13] M. Rombouts 2006[14] C. Over 2003

Points of attention• Extreme small meltpool (µm3), followed by extreme fast cooling

(10MK/sec), remelting, reheating (HAZ)• Powder:

o Fluidity (Hall, angle of repose)o Distribution (rather small Gausian)o Shape (equiaxial)

• Producto Porosityo Keyholeso Oxidationo Internal stresseso Cracking: solidification cracking, liquation cracking, ductility dip

cracking, ductile to brittle transition cracking)o texture

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.

Properties of As Build Materials by AM

Property AM Parts Compared to Conventional ProcessingStiffness EqualStrength As Strong or StrongerHardness As Hard or HarderDuctility Less DuctileFatigue (Cyclic) WeakerToughness Less Tough

CracksPorosityStrong Texture

Adapting post processing andcomposition

1. Different post processing for SLM produced materials• Ti6Al4V• AlSi10Mg• 18Ni300 Maraging Steel

2. Different composition to improve properties• Ti6Al4V + Mo• AlSi10Mg + Cu• AlSi10Mg + TiB2

3. Different composition to improve processability• Al7075 + Si

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65 parts manufactured simultaneously

Variation of 3D printed parts

Process

Embodied material

energy (MJ)

Embodies process

energy (MJ)

Material &

process energy

Carbon Footprint

of part1

Scenario 1:

Machining

670 MJ 10.3 MJ 680.3 MJ 102 Kg CO2

Scenario 2: SLM

Lattice

105 MJ 33.6 MJ 138.6 MJ 21 Kg CO2

Scenario 3: SLM

optimal

125 MJ 44.8 MJ 169.8 MJ 25 Kg CO2

Three design scenarios for holder hinges in airplane cabin: 1) the current design, 2) design optimised for SLM using lattice structure, and 3) a topological optimised design

Required energy and CO2 emissions to provide part according to above scenarios

1 CO2 based on energy mix of USA (2007): 1 kW.h = 3.6 MJ = 0.54 Kg CO2

P. Reeves, The Business Drivers to Additive Manufacturing –Stimulating technology adoption-, RapidTech, Editor. 2012, Econolyst Ltd: Erfurt, Germany

AM aerospace components; (a) an injector block, (b) a combustion chamber made with lattice structure to reduce the weight by 88%, and (c) an expansion nozzle (Courtesy of LayerWise-ESA).

Space applications

Design of moulds: an example of conventional (a) and conformal (b) cooling channels [7]

Conformal cooling

Medical devices• Crafting model organs for enhanced imaging

• From prosthetic limbs to exoskeletons

• Crafting artificial bone replacement

• Creating dental crowns and bridges

• Much more customizable

• Creating complex geometries that cannot be machined

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Spinal - Cages - Artificial Discs- Staples

Cardiovascular- Housings - Valves - Connectors

Orthopaedic- Large joints (Hip, Knee, Shoulder)

- Small joints (Ankle, Toes, Elbows)

Trauma/Fixation- Various screws- Plates (locking,

compression ...)

Craniomaxillofacial- Mandible - Skull plates - Zygoma/orbit

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Dr. Benet, SpainDr. Benet, Spain

The planning and the implant placement by a surgical guide produced in PA

Standard implantsExamples

Ti6Al4V ELI Tantalum

Patient-specific implantscase 1: world’s first 3D printed full mandible

Customer: ,NLMaterial: Ti6Al4V ELI

Patient-specific implantscase 1: world’s first 3D printed full jaw implant

benefits:

perfect fit

restoration of aesthetics

recovery of vital functions

short operation time (4h)

short hospitalization (2d)

HA coating

screw holes for dental prosthesis

Customer: ,NLMaterial: Ti6Al4V ELI

Patient-specific implantscase 2: triflange acetabular hip implant

benefits:

perfect fit

porous structures – no need for bone grafting

screw positioning

short lead time

Customer: , BEMaterial: Ti6Al4V ELI

A custom Titanium implant was used to replacea cancer patient’s sternum and parts of rib cage

A special mask was printed to improve the face of a cancer patient

3D anatomical models

3D printing for regenerative medicine• Printing appropriate 3D scaffolds (HA, TCP, PCL, PLGA,

PEEK, Silk)

• Loading the scaffolds with cells, either on the surface or in micro-pores/channels), concomittant with the production of the scaffold (applying different reservoirs) or after printing :

o Fibroblast growth factors

o BMP for osteoinduction (Bone Morphogenetic Proteins)

o VEGF for vein growth (Vascular Endothelium Stem Cells)

o hASCs (human adipose stem cells)

• Ectopic versus orthotropic

• Applications: drug release, bone, cartilage, tooth, skin41

Bioprinting• Cells are used like "ink“, mixed with naturally or synthetic

polymers

• Bioprinting is more complicated than other 3D printing

• Bioprinting with autologous cells could prevent Organ Transplant Rejections

• Printing organs could eliminate waiting times.

• Printing the networks of veins is a large obstacle

• 3D printed tissues for pharmaceutical testing

• Ethical issues

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What will be possible in the future?

- printing in vitro

- printing in vivo (during surgery)

Scan V. Murphy and Anthony Atala,Nature biotechnology12, august 2014, P; 773-785

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Food printing• Customized, nutritionally-appropriate meals synthesized

one layer at a time

• Refill cartridges (might prevent food waste)

• For extended space expeditions

• New cooking techniques adding new textures and flavors.

• New recipes (the pizza printed for NASA took only 70 seconds to cook)

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The food printing process begins with selecting the required food canisters in which ingredients are stored and kept refrigerated. Ingredients are then fed into a mixing chamberand the mixture is extruded and deposited in layers of various and complex combinations of ingredients. During deposition of the layers onto the serving tray the ingredients are either cooked or cooled in the chamber or by heating/cooling tubes attached to the printing head.

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Soon you are about to download the recipe from internet and enter a code to your printer,and you get your food in your hand.

vegetarian nuggets made of chickpeas,bread crumbs, garlic, spices, olive oil, and salt

The sugar shape is a 3/4 twist mobiusstrip with a square cross section and windows cut at regular intervals in all of the sides the side.

pasta pizza46

Clothing and Fashion• Perfect fitting

• Gives everyone access to creativity

• One-of-a-kind, perfectly tailored piece

• Needs appropriate material to print (ABS, Nylon, TPU-92A-1) (limited choice so far)

• 3D printed flexible textile structures

• Glass frames, juwels, decoration

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First a trained specialist will take a dynamic scan of your gait using RSscans’s Footscan© system

The specialist can then analyze your footprint to see where exactly and in which direction you need some extra support. This is just a screenshot, but in the software we can see all the dynamic pressure distribution and foot movement

Based on the specialist’s analysis, a design is generated, which is sent to Materialise.

Materialise then “engineers” this design into a manufacturablepart, which is then 3D printed. Finally a cushioning layer is mounted on top to finish the insole. The finished product is then packed and shipped to you!

3D Printed Insoles: Customized to Support Your Every Move

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3D printed textiles

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Printing Buildings• New materials:

o Mixing sand with a binding agent

o a special ink, consisting of construction waste and industrial waste wit a binder

o Clay and wood

• Building faster, cheaper, safer

• In how far can wind, rain, humidity influence the quality?

• You don’t like your bathroom? Print another one. Broken a door? Print a new one.

• A new era of architecture can be created.

• Legal and political factors still unclear.50

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The first four store 3D printed building by Winsun, built within 24 hours

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3D-printed weapons foundduring Australian police raid

Possible 3D-printed gun parts found by Queensland Police Service. Main image: 3D-printed knuckleduster seized during the same raid

American company has built and successfully fired the world's first metal3D-printed gun.

Printing weapons

http://www.dezeen.com/

EVERYTHING?• Limited by printable materials but new materials can be

developed

• Can everybody print everything he likes to print?

� Ethical issues

� Law issues

• 3D printed electronics

• Can 3D printing defy physics? Man claims to have printed "Impossible Triangle"

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GE fired up world’s largest commercial jet engine u sing 3D-printed metal parts

https://qz.com/667477/ge-fires-up-worlds-largest-commercial-jet-engine-using-3d-printed-metal-parts/

The future of 3D printing

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Why 4D Printing• To generate self-transforming structures with complex

geometry

• Fabrication of self-evolving structures when multiple materials can react to the environment and deform over time

• A variety of highly specific joint designs for folding, curling, twisting, linear expansion/shrinking…

• Self-healing of complex structures

• 4D printing for Biomedical Applications: 3D biocompatible materials or living cellular constructs continue to evolve over time

Action �Result �

Optical Mechanical(Shape)

Electric Magnetic Chemical Thermal

Optical •Photochromism•Fluorescence•Photoreative

• Mechanochromic paints

•Electrochromic liquid crystals•Electroluminescence

•pH-dependent•Mixing

•Thermochromism

(Actuator)Mechanical(Shape)

•Photostriction•Photo-induced shape memory polymers

•Polymers with negative Poisson coefficient•Pseudoelastic materials (SMA)•Nanosized Cu, Au, Ag

•Electrostriction•Piezoelectric•Electroactive polymers•Carbon Nano Tubes• Electrorheological Fluids

•Magnetostriction•Magnetic SMA•Magnetic SMP•Magnetorheolo-gical Fluids

•Hydrogels•Shape change materials

•Shape memory alloys (SMA) / polymers/ceramics•Thermal dilatation•Bimetals

Electric •Photoconduction•Pyroelectric materials

• Piezoelectric •Conductors and semi-conductors

•Seebeck-effect(thermocouple)•PTC-NTC resistance materials

Magnetic • Magnetoelectric materials

•Magnetic transitions

Chemical •Photodegradable materials•Curing of polymers

• Mechanochemical materials

•Curing of polymers

Thermal •Peltier elements •Magnetocaloric effect

•Phase change materials

Stimuli-responsive materials

Techniques that can be used for 4D printing (single and multiple materials )

• Fused deposition modelling (applying different filaments simultaneously)• Polyjet printing ( each cartridge can contain a different material)• Digital Projection Printing ( several syringes can inject different materials)• Laser Cladding ( different materials can be injected in the laser beam)• Magnetic Field-assisted Projection Stereolithograph y :

o nano- and micro-sized ferromagnetic particles are deposited with designed patterns in liquid polymer by using a programmable micro-deposition nozzle

o Result: tunable elastic properties, giant deformational effects, high elasticity, anisotropic elastic and swelling properties, and quick response to magnetic fields

• Micro- and nano-drop printingo Resolution <5µm

• Electrochemical printing using microfluid delivery o f electrolyteso Resolution 100nm

• Selective laser melting (at this moment for single materials only)

Materials for 4D printing• Temperature responsive materials

o Shape memory alloyso Shape memory polymerso Hydrogels

• Humidity-responsive materialso Hydrogelso Cellulose based material

• Chemical responsive materials• Mecano-responsive materials• Electrical responsive materials

o Regulation of electrical conductivity• Magnetic responsive materials• Light responsive materials

o Photodegradation of polymers

You do not need to ask questions but if you feel the need for it, please do so!

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