|
7215 |
|
Feasibility of additive manufacturing of WC-Co cermet parts by laser powder bed fusion |
|
Kevin Papy / TECHNOGENIA/ENISE, France Zoe Roulon / TECHNOGENIA/ENISE, France Jean-Marc Staerck/ TECHNOGENIA, France Philippe Bertrand/ CENTRALE LYON / ENISE, France Alexey Sova/ CENTRALE LYON / ENISE, France Andras Borbely/ MINES ST ETIENNE, France Julien Favre/ MINES ST ETIENNE, France Julien Sijobert/ CENTRALE LYON / ENISE, France |
|
Cermet is composite material consisting of a ceramic reinforcement and a metal matrix. Conventional tungsten carbide cermet parts containing a cobalt matrix phase are principally produced by powder sintering. Laser Powder Bed Fusion (LPBF) is an additive manufacturing technology widely applied for direct fabrication of functional parts with complex geometry metal parts. The present paper deals with the feasibility of additive manufacturing of cermet part by LPBF using WC-Co powder for HVOF applications. The results showed that parametric optimisation of LPBF process allowed producing of solid WC-Co part. However, structure analysis revealed the presence of significant number of pores (1.41%) and small-scale cracks inside the built samples. It was also found the size of WC grains was increased after manufacturing in comparison with the initial powder. Applied thermal post-processing, such as heat-treatment and HIP (high isostatic pressure) significantly improved the structure of manufactured parts. The porosity of the samples after HIP was close to almost zero (0.01%). Phase analysis revealed that the samples after heat treatment and HIP had a uniform structure. Undesirable phase W2C is present in the sample before thermal post-processing. The abrasive wear tests showed that the wear resistance performance of additively manufactured parts, with a mass loss of 8.11 mm3 for raw sample, was comparable with reference ones produced by powder sintering. High values of hardness 1096HV, 1120HV and1152HV at a load of 30kgf are observed respectively for WC-Co raw sample, heat treated sample and HIP sample. In general, the feasibility study successfully demonstrated the possibility of manufacturing of wear-resistant cermet special tools by LPBF. |