10th european forum on rapid prototyping - paris – 17-19 ... · prototype testing on corpse sla...

DMLS direct part case studiesmedical and aeronautical applications

10th European Forum on Rapid Prototyping - Paris – 17-19/09/04

Pôle Européen de Plasturgie(PEP) – France

Dr Bruno LE RAZER

In collaboration with:


INTRODUCTION

• Description of PEP• Description of laser sintering machine• 2 Case studies: medical and aeronautical fields• New EOS M270 DMLS machine


PEP

LyonLyon

OyonnaxOyonnax

ParisParis

• Oyonnax: “Plastic Vallée”– Biggest plastic processing area in France– ~600 companies

• PEP: Research and technological facility– Created in 1989, 46 employees– Specialised in plastic processing– Service bureau: Mould trials, lab, metrology,

training– R&D: research projects, industrial

development

– RP machine: tooling and direct part


RP MACHINES

• Several new machines on the market

Gluing + FurnaceGluing + Furnace

Electron beamElectron beam

DTMDTM

ArcamArcam

(SLS)

(SLM)

(EBM)

Direct methodDirect method

SinteringSintering

FusionFusion

EOSEOS

Phenix / MCP / EOSPhenix / MCP / EOS

Concept LaserConcept Laser

TrumpfTrumpf

(DMLS)

(DMLM)

Laser CO2, 240W

Laser fibre IPG50 to 200W

Laser YAG, Foba100 W

Laser disc Trumpf200W

3D printing3D printing PrometalPrometal

Laser CO2, 100W

Indirect methodIndirect method

LaserLaser

LaserLaser

LaserLaser


EOS M250Xtended MACHINE

Build volume: 250 x 250 x 180 mmCO2 laser: 240W, 180W en surface2 powders 20µm: steel (DS20) and bronze (DM20)

Layer thickness: 0.02mmAccuracy: +/- 0.05mm

Direct Metal Laser Sintering

Direct Production of inserts or partsDirect Production of inserts or partsMinimum post-treatment (shot-peening)


PRINCIPLE

DMLS


FABRICATION


DS20 POWDER

Magnetic powder Non-magnetic powder

Fe Ni + Fe + C Cu + P


FABRICATION PARAMETERS

• For thick parts:External (_3s) and internal (_3i) skin and core (_2c)

• For thin parts:External skin (_3s)


SHOT-PEENING

MicrohardnessMicrohardness

253 Hv(Surface)

264 Hv(Surface)

ShotShot--peenedpeened surfacesurface

AsAs--received received surfacesurface

RoughnessRoughness

Ra = 13 µm

Rz = 48 µm

Ra = 4 µm

Rz = 15 µm

70µm

70µm

Steel and ceramic ballsReduction of stressReduction of porosityBetter surface finish

0.5mm

0.5mmShotShot--peenedpeened surfacesurface

As-received surface

Z

X-Y


IMPORTANT QUESTION

How to build a “good” Direct metal part ?

• Part analysis is crucial• Support structure • Building stage• Finishing/machining stage

Build strategyEnough but not too many ParametersHow to finish part?


CASE STUDY PARTNERS

• Depuy: part of Depuy Inc and Johnson&Johnson– designer, manufacturer and distributor of orthopaedic

devices– 200 employees, turnover: 60M€, market leader

• Turbomeca: part of SNECMA Group– leading manufacturer of low- to medium-power gas

turbine for helicopters– 4000 employees, turnover: 653M€


MEDICAL APPLICATION

• Background information:– Team of several R&D project managers & CAD engineers– Several French and international competitors– Regular production of patented products (small volume)

• New product:– Development phases: long and costly– Test, validation and production– Several prototypes: visual, functional

Prototype testing on corpse

SLA models: quick & good resultsNo mechanical test

Casting, machiningdelay

44--6 6 weeks weeks or moreor more


APPLICATION: METATARSO-PHALANX IMPLANT

• Implant to replace joint between metatarsal bone and proximal phalange (big toe joint) on foot

• Several instruments / fixtures used during surgery Picture of implant


Instrument for insertion of the first intra-medullary pin into the

metatarsal bone


Guide for rotating adjustment(// to sesamoid plane)


Metatarsal cutting guide linked with rotating guide


Metatarsal cut


Phalanx cutting guide insertedinside metatarsal guide


Phalanx cut


Final implantation of metatarsal and phalanx implant


REQUIREMENTS

• Fast production of 7 direct parts– Complex geometry– Functional use– Dimensions: ~ 60 x 25 x 15 mm

Rapid Manufacturing : DMLS with Direct Metal DM20

SOLUTION


Support structures

FABRICATION7 parts in one fabrication:

• Support: 3 h• Fabrication: 18 h• Finishing: 10 h

Total: 4 days

160x160mm plate Height: 41mmVolume: 18 cm3


PICTURES OF FINISHED DM20 PARTS


PICTURE OF DM20 PARTS IN USE


ANALYSIS

• Material:– Production: stainless steel but not important for the application– DirectSteel DS20: stress too important, support difficult to be removed– DirectMetal DM20: can not be directly used for direct joint arthroplasty

• Time reduction:– Traditional way: 6 weeks

– DMLS 1 week

• Price– Still too expensive– Reason: separate orders!

CAD data Data preparation Machining / EDM

CAD data Sintering


CONCLUSION

• Development phase of new products: shorter• Possibility of real test with prototype

BUT

• Complex and small geometry: limitation of M250• Support structure: difficult to remove • Material: limitation

AERONAUTICAL APPLICATION

Background information:So far production of 50000 engines worldwide, 14500 turbines in operation

Active competitors around the worldDevelopment of new engine: 3 years

Creation of innovative complex product in less timeIncrease productivity and efficiency

Interest in new technologies such as Rapid ManufacturingRapid Manufacturing


WHY RAPID MANUFACTURING ?

• Aim:

RapidRapid ManufacturingManufacturing of rotor of rotor andand stator for test stator for test rigsrigs(low temperature: ~250°C – 30 to 40000 rpm)

• Pros:– Reduction of cost and production time– Change of design

• Cons:– Only a prototype can be available!

• Machines:– Several on the market– EOS M250 most promising so far


INITIAL OBJECTIVES

• Production of stator for MAKILA 2A engine

(Minimum size φ 250mm x H 60mm)

3 stators

StudentStudent::«« 10 10 days days »»

«« Free of chargeFree of charge »»

????


• Intitial test on DS20 samples:– OK to be used on test rig

• Dimensions:– φ 180-246mm x h 52mm, 270cm3, 4kg

• Blades:– Thickness: 0.5-1.8mm, number: 41

• Application:– Test rig: 30000rpm, 250°C

M

STATOR

echanical properties


MECHANICAL TEST

• Test bars: traction, flexion, wear• Several sizes and build directions


SUMMARY OF FABRICATION Fab 1: part with no support (25h)

Very bad resultLack of material

Delamination

Fab 2: part with support (25h)Better result

Blade OK – dimensions OKSlight délamination1st evolution

Fab 3: Full stator (138h)Built OK but defects

Visible cracksDimensions OK

2nd evolution


Cracks (horizontal and

vertical)

Delamination

• Full stator with support structure under each blade• Fab with a compression ring to minimise stress• Analysis on support structure• Problem with blade parallel to scraper

FULL STATOR


MACHINING STAGE

• Wire EDM to remove plate• Supports machined off• Welding• Polishing


RESULTS

• Dimensions: OK– Each blade within +/-0.05mm, inside tolerances– Inner and outer rings OK

• Geometry:– Cracks and blade welded– No deformation

• Delay– 3 attempts, 3 months


PICTURE OF FINISHED PART


COMPARISONS

Overall cost: X €

Time: 3 months

Traditional technologies Rapid Manufacturing

• Material (φ 250) 0.5 % 190 d*

• Preparation 32.5 % 26 d(CNC program & tooling)

• Machining 77 % 40 d(milling, thermal treatment, polishing)

• Material (DS20 powder) 4 % 14 d*

• Preparation 5 % 2 d(EOS Data, m/c parameters)

• DMLS 63.5 % 8 d

• Finishing 27.5 % 20 d(shot-peening, milling, EDM, polishing)

(*) Separate ordersOverall cost: X/2 €

Time: 1.5 month

- 50 %


CONCLUSION

• Complex geometry• Not easy to build but possible• Further work needed to get better and quicker results• Material: limitation

New development

• Bigger parts• Better material for production parts with better surface finish• Quicker process


EOS M270 MACHINE

• Total fusion

• Same build size

• Brand new laser

• Mechanical improvements

• Software improvements


M270: LASER DETAILS

• Ytterbium fibre laser (manufacturer IPG) 200W– Wavelength: 1,06µm

• Better absorption for metallic powders• Less residual stress: less cracks

– Smaller beam size: 100µm• Higher energy density• Better detail resolution• Thinner support structure: easier to remove

– Dual focus: from 100 to 500µm• Higher productivity• Small and slow on the outside, bigger and faster o the inside of a part• Easier process optimisation for new type of materials


M270: MECHANIC DETAILS

• Scraper– More rigid, new design– Optimised movement, faster

• Plateform– Easier manipulation , quicker to start build

• Process chamber– Gas tight– Different type of gas can be used


M270: MATERIALS

• Existing powders:– DS20 steel and DM20 bronze: better surface finish and 30% faster– DSH20 hard steel: less cracks, for tooling application

• EOS R&D work– Stainless steel 1.4542 (17-4PH)– Tool steel 1.2344 (H13)– Inconel 625 (2.4856)– Titanium

• Futur– Possible collaboration with EOS– Other powder manufacturers

10th european forum on rapid prototyping - paris – 17-19 ... · prototype testing on corpse sla...

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