Microstructural Stability of Co28Cr6Mo Biocompatible Alloy Produced by Additive Manufacturing

Thanks to their excellent corrosion and wear resistance CoCrMo alloys are widely employed in the production of medical devices. Additive Manufacturing (AM) allows the fabrication of customized devices to fit the patient anatomy improving the implant functionality. AM gives rise to CoCrMo alloys with a fine cellular microstructure consisting of metastable. phase and stable e phase. This work investigated the microstructural stability of a Co28Cr6Mo alloy printed by Selective Laser Melting (SLM) after a heating-cooling cycle from room temperature to 800 degrees C. The results of X-ray diffraction (XRD) measurements, Light Microscopy (LM) observations and X-ray Photoelectron Spectroscopy (XPS) analyses show that part of the metastable. phase transforms into the stable e phase, and Mo and Cr diffuse towards the surface forming a stable oxide layer.