Selective Laser Melting versus Electron Beam Melting

tat actuel des fabrications additives pour les applications mtalliques Atelier CNES 18/19 Novembre 2013, Toulouse, France

Olivier RIGO

Carsten ENGEL

25.11.13 1 sirris | www.sirris.be | [email protected] |

Special thanks

Le Fonds Europen de Dveloppement Rgional et la Rgion Wallonne investissent dans votre avenir.

25.11.13 2 sirris | www.sirris.be | [email protected] |

Sirris | Metal Additive Manufacturing

25.11.13 3

Index

Sirris short overview

Generalities:

Metal Additive Manufacturing

Technology comparison: LBM vs EBM

Metallurgical aspects

Mechanical aspects

Case studies

Contact

sirris | www.sirris.be | [email protected] |

Sirris | Driving industry by technology

130 experts & hight-tech infrastructure

Collective centre of the technology industry Non profit organization Industry owned

4,700 industrial interventions (advice, projects, services) within 1,700 different companies whose 75% are SMEs 24M EUR turnover

Mission: Increase the competitiveness of companies of the Agoria sectors through technological innovations

Sirris | 23 years of Additive Manufacturing

AM centre Leading position in EU 16 engineers and technicians 17 high-tech additive technologies in house Most complete installed base in EU Driving technology companies in applications

Technologies: Stereolithography (normal & hi-res) Paste polymerisation for ceramics and metals (Optoform) 3D Printing of plaster and metal powder Laser sintering of polymeric powder (PA,): P360 P390 Objet Connex 500: bi-material Laser sintering of metal powder (parts and mould inserts) Electron Beam Melting (Arcam A2) 3D Printing of wax (Thermojet) Vacuum Casting of Alu, Bronze, Zamak Laser Cladding (EasyClad) Laser Beam Melting (MTT) Bi-material FDM system [email protected] system (for students) MCOR technology (color 3Dprinter)

25.11.13 5 sirris | www.sirris.be | [email protected] |

Sirris | Metal Additive Manufacturing

25.11.13 6

Index

Sirris short overview

Generalities:

Metal Additive Manufacturing

Technology comparison: LBM vs EBM

Metallurgical aspects

Mechanical aspects

Case studies

Contact

sirris | www.sirris.be | [email protected] |

Generalities: Metal Additive Manufacturing

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Direct

Fabrication

system

Laser

E-Beam

Print head

Nozzle

Post-

processing

Indirect

Binder

Debinding

+ sintering

Post-

processing

Generalities: Metal Additive Manufacturing

Electron Beam Melting (EBM)

Laser Beam Melting (LBM)

Metallic powder deposited in a powder bed Electron Beam Vacuum Build temperature: 680-720C

Metallic powder deposited in a powder bed Laser Beam Argon flow along Ox direction Build temperature: 200C

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Generalities: Metal Additive Manufacturing

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Electron Beam Melting

Generalities: Metal Additive Manufacturing

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Electron Beam Melting

Benefits and drawbacks - EBM

Benefits Drawbacks

Few developed materials, only conductive materials possible

Tricky to work with fine powder

Powder is sintered -> tricky to remove (e.g. interior channels)

Long dead time between 2 productions (8 hours for cooling A2, A2X, A2XX systems)

Sintered powder = good for thermal conductivity = less supports

Suitable for very massive parts

Less supports are needed for manufacturing of parts

Possibility to stack parts on top of each other (mass production)

Process under vacuum (no gaz contaminations)

High productivity

No residual internal stress (constant 680-720C build temperature)

Very fine microstructures (Ti6Al4V), very good mechanical and fatigue results (Ti6Al4V)

Expensive maintenance contract

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Generalities: Metal Additive Manufacturing

Electron Beam Melting (EBM)

Laser Beam Melting (LBM)

Metallic powder deposited in a powder bed Electron Beam Vacuum Build temperature: 680-720C

Metallic powder deposited in a powder bed Laser Beam Argon flow along Ox direction Build temperature: 200C

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25/11/2013 Sirris | www.sirris.be | [email protected] |

13

Spread powder

Recoater

Laser beam

Melted zones

Previous layers

Initial plate

Argon

Main tank

The building steps

Generalities: Metal Additive Manufacturing

Laser Beam Melting SLM Solutions 250HL

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Benefits and drawbacks - LBM

Benefits Drawbacks

Flexibility for new material developments

Possibility to work with fine powders 10m (d50)

Easy powder removing from the parts (the parts are not embedded in pre-sintered cake)

Short dead time between 2 productions (2 hours for cooling)

Possibility of restarting an interrupted job

Easy visual inspection of building process during the manufacturing (either with unaided eye or with optical camera)

Process is wall thickness dependent. (not suitable for massive parts)

Process involving internal stresses in the parts need additional annealing

Process requiring strong supports for parts fasten during the manufacturing (not only for heat transfer)

Need to use build plates of the same material than the powder used in the machine (e.g.: more expensive for titanium powder)

Cutting tool necessary (eg: a saw) in order to release the parts from the build plate

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Technology comparison EBM LBM

LBM EBM

Size (mm) 250 x 250 x 350* 210 x 210 x 350*

Layer thickness (m) 30 - 60 50

Min wall thickness (mm) 0.2 0.6

Accuracy (mm) +/- 0.1 +/- 0.3

Build rate (cm/h) 5 - 20 80

Surface roughness (m) 5 - 15 20 - 30

Geometry limitations Supports needed everywhere (thermal,

anchorage)

Less supports but powder is sintered

Materials Stainless steel, tool steel, titanium, aluminum,

Only conductive materials (Ti6Al4V, CrCo,)

CENG 25/11/2013 sirris 2013 | www.sirris.be | [email protected] | 16

*1 SLM Solutions 250HL *2 Arcam A2

0

2

4

6

8

10

productivity

3D complexity

maximum size

Accuracy Surface finish

mech prop -

density

material range

EBM (Arcam)

LBM (SLM Solutions

Technology comparison EBM LBM

CENG 25/11/2013 sirris 2013 | www.sirris.be | [email protected] | 17

*1 SLM Solutions 250HL *2 Arcam A2

Sirris | Metal Additive Manufacturing

25.11.13 18

Index

Sirris short overview

Generalities:

Metal Additive Manufacturing

Technology comparison: LBM vs EBM

Metallurgical aspects

Mechanical aspects

Case studies

Contact

sirris | www.sirris.be | [email protected] |

Metallurgical aspects LBM & EBM

Electron Beam Melting (EBM)

Laser Beam Melting (LBM)

Metallic powder deposited in a powder bed Electron Beam Vacuum Build temperature: 680-720C

Metallic powder deposited in a powder bed Laser Beam Argon flow along Ox direction Build temperature: 200C

25/11/2013

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Experimental procedures

Electron Beam Melting (EBM)

Laser Beam Melting (LBM)

Random scanning strategy Vacuum Pre-heating of the subtrate: 680-720C

Complex lasing strategy: 79 rotation between two successive layers Argon flow along Ox direction Pre-heating of the subtrate: 200C

Characteristics of theTi6Al4V ELI powders

Process Ti (wt%) Al(wt%) V(wt%)

LBM Bal 5,9 4,2

EBM Bal 3,3 4,4

Reference axis for EBM and LBM

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Results and discussion

Laser Beam Melting

Perpendicular to the building direction

Equiaxed morphology (around 50m of diameter) Width does NOT significantly change along the height

No evolution of the thermal gradient intensity, no evolution of the grain

width

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Results and discussion

Laser Beam Melting

Parallel to the building direction

Elongated grains characteristic of an epitaxial growth aligned with the heat flow

No epitaxial growth apparent

Explanation: Tilt of the primary grains

Suggestion: combined effect of part geometry and a modification of the direction of the maximum heat flow that had possibly been brought about by the Argon flow

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Results and discussion

Perpendicular to the building direction

Equiaxed morphology as for LBM

Electron Beam Melting (EBM)

Parallel to the building direction

Explanation: Random scanning trategy Thermal hom