Two-component metal injection moulding of Ti-6Al-4V and stainless steel Bi-material parts

Two-component metal injection moulding (2C-MIM) allows producing functionallygraded metal parts of complex shape by co-sintering. Until now several studies have demonstratedthat different material properties can be combined. Another promising material combination istitanium and iron-based materials. It can combine the biocompatibility and low density of titaniumwith a ductile and cost efficient stainless steel. However, co-sintering these materials revealschallenges due to a significant mismatch in sintering shrinkage and limitations in sinteringtemperature for both materials. The recent study showed that Ti-6Al-4V can be joined to thestainless steel 316L by 2C-MIM provided that certain constraints are taken into account. Thequality of the interface before and after co-sintering is a crucial factor for intact parts afterprocessing. By applying sinterdilatometry the mismatch in shrinkage was compensated by usingadjusted powder characteristics and tailored feedstock compositions. A co-sintering cycle wasdefined with regard to the sintering characteristics of both materials. The developed two-componentspecimens revealed significant interdiffusion of alloying elements at the Ti-6Al-4V / 316L interfaceand a tensile strength of about 200 MPa after co-sintering.