Binder Jetting of Co-Cr-Mo Alloys for Biomedical Applications: A Tribocorrosion Perspective

This paper investigates tribocorrosion properties of binder jet additive-manufactured Co-Cr-Mo (F75) parts. Various parameters, including sintering atmosphere and post heat treatment processing, were examined to understand their effect on open circuit potential, friction, wear coefficient, and hardness. Results demonstrated that samples sintered in N 2 -5%H 2 atmosphere have more noble potential up to-0.13V and lower wear coefficient down to 4.85e-6 mm 3 /N.m in comparison with samples sintered in vacuum. Solutionizing and aging (SHT-A) significantly increases hardness up to 626HV and lowers wear coefficient which means that the sample is more resistant to wear compared to as-sintered (AS) samples. However, heat-treated samples present slightly lower initial potential which means that these samples are more chemically active. This is because of the phase transformation of the matrix from FCC Co (γ phase) in AS condition to HCP Co (ε phase) + Co-Cr intermetallic (σ phase) in SHT-A condition, and different precipitate (carbides and nitrides) formation between these samples.