Electron Beam Melting.pptx

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1. 1 Electron Beam Melting BY :- Anmar Talal University of Diyala College Of Engineering Materials Engineering Department

2. Introduction bonding of the metal, ceramic or plastic powders together when heated to temperatures in excess of approximately half the absolute melting temperature . In the industry, sintering is mainly used for metal and ceramic parts (Powder Metallurgy). After pressing (compaction) of the powder inside mold for deforming into high densities, while providing the shape and dimensional control, the compacted parts are then sintered for achieving bonding of the powders metallurgically. 2

3. + Sintering in additive manufaturing Sintering process used in additive manufacturing differs from the Powder Metallurgy, such as: Plastic based powders, in addition to metal powders Local sintering, not overall sintering Very short sintering period Laser (heat source) is exposed to sections to be sintered for a very short time. Hard to achive an ideal sintering. In some applications, for achieving the ideal sintering, the finished parts are heated in a separate sintering oven. 3

4. + Sintering in Metallurgy vs AM HEAT PRESSURE TIME HEAT 4

5. + Electron Beam Melting (EBM) Electron Beam Melting (EBM) is a type of rapid prototyping for metal parts. The technology manufactures parts by melting metal powder layer per layer with an electron beam in a high vacuum. Unlike some metal sintering techniques, the parts are fully solid, void-­‐free, and extremely strong. EBM is also referred to as Electron Beam Machining. H igh speed elect ro ns .5 -­‐ . 8 t i m es the speed o f light are bombarded on the surface of the work material generating enough heat to melt the surface of the part and cause the material to locally vaporize. EBM does require a vacuum, meaning that the workpiece is limited in size to the vacuum used. The surface finish on the part is much better than that of other manufacturing processes. EBM can be used on metals, non-­‐metals, ceramics, and composites. 5

6. + Electron Beam Melting (EBM) Dispensed metal powder in layers Cross-­‐section molten in a high vacuum with a focused electron beam Process repeated until part is completed Stainless steel, Titanium, Tungsten parts Ideal for medical implants and injection molds Still very expensive process 6

7. Generalities: Metal Additive Manufacturing Electron Beam Melting 7

8. + Examples of EBM 8

9. Generalities: Metal Additive Manufacturing Electron Beam Melting 9

10. + EMB benefit High productivity Suitable for very massive parts No residual internal stress (constant 680-­‐720°C build temperature) Less supports are needed for manufacturing of parts Possibility to stack parts on top of each other (mass production) Sintered powder = good for thermal conductivity = less supports Process under vacuum (no gaz contaminations) Very fine microstructures (Ti6Al4V), very good mechanical and fatigue results (Ti6Al4V) 10

11. + EBM drawbacks Powder is sintered -­‐> tricky to remove (e.g. interior channels) Long dead time between 2 productions (8 hours for cooling – A2, A2X, A2XX systems) Tricky to work with fine powder Expensive maintenance contract 11

12. Experimental procedures Electron Beam Melting (EBM) Random scanning strategy Vacuum Pre-heating of the subtrate: 680-720°C Reference axis for EBM and LBM 12

13. + Comparison Electron Beam Melting (EBM) Laser Beam Melting (LBM) Metallic powder deposited in a powder bed Electron Beam Vacuum Build temperature: 680-720°C Metallic powder deposited in a powder bed Laser Beam Argon flow along Ox direction Build temperature: 200°C 13

14. + Comparison LBM EBM Size (mm) 250 x 250 x 350*¹ 210 x 210 x 350*² Layer thickness (µm) 30 - 60 50 Min wall thickness (mm) 0.2 0.6 Accuracy (mm) +/- 0.1 +/- 0.3 Build rate (cm³/h) 5 - 20 80 Surface roughness (µm) 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,…) *1 SLM Solutions 250HL 14

15. + Comparison 15

16. + Comparison 10 8 6 4 2 productivity 3D complexity maximum size Accuracy Surfa c e fin i sh mech prop - density material range EBM (Arcam) LBM (SLM Solutions *1 SLM Solutions 250HL 16

17. References "ASTM F2792 - 12a Standard Terminology for Additive Manufacturing Technologies, (Withdrawn 2015)". Astm.org . "Electron Beam Melting". Thre3d.com. Archived from the original on 3 February 2014. Retrieved 28 January 2014. Sames ; et al. (2014). "Thermal effects on microstructural heterogeneity of Inconel 718 materials fabricated by electron beam melting". Journal of Materials Research. . "ORNL research reveals unique capabilities of 3-D printing | ornl.gov". Guo , Qianying ; Kirka , Michael; Lin, Lianshan ; Shin, Dongwon ; Peng, Jian; Unocic , Kinga A. (September 2020). "In situ transmission electron microscopy deformation and mechanical responses of additively manufactured Ni-based superalloy ". Scripta Materialia . 186: 57–62. 17