Microstructure of As-cast Co-Cr-Mo Alloy Prepared by Investment Casting

• Published in: Journal of the Korean Physical Society Vol. 72; no. 8; pp. 947 - 951
• Main Authors: Park, Jong Bum, Jung, Kyung-Hwan, Kim, Kang Min, Son, Yong, Lee, Jung-Il, Ryu, Jeong Ho
• Format: Journal Article
• Language: English
• Published: Seoul The Korean Physical Society 01.04.2018; Springer Nature B.V; 한국물리학회
• Subjects: Biocompatibility; Casting; Casting alloys; Chromium base alloys; Cobalt base alloys; Corrosion resistance; Emission analysis; Field emission microscopy; Grain boundaries; Investment casting; Mathematical and Computational Physics; Microscopy; Microstructure; Optical microscopy; Particle and Nuclear Physics; Physics; Physics and Astronomy; Precipitates; Scanning electron microscopy; Sigma phase; Surgical implants; Theoretical; 물리학; ASTM F75; Microstructure; Co-Cr-Mo alloy; Metal carbides
• ISSN: 0374-4884; 1976-8524
• DOI: 10.3938/jkps.72.947

The microstructure of a cobalt-base alloy (Co-Cr-Mo) obtained by an investment casting process was studied. This alloy complies with the ASTM F75 standard and is widely used in the manufacturing of orthopedic implants owing to its high strength, good corrosion resistance, and excellent biocompatibility. This work focuses on the resulting microstructures arising from normal industrial environmental conditions. The characterization of the samples was carried out using optical microscopy, field emission scanning electron microscopy and energy-dispersive spectroscopy. In this study, the as-cast microstructure is an γ-Co (face-centered cubic) dendritic matrix with the presence of a secondary phase, such as M 23 C 6 carbides precipitated at grain boundaries and interdendritic zones. These precipitates are the main strengthening mechanism in this type of alloy. Other minority phases, such as the σ phase, were also detected, and their presence could be linked to the manufacturing process and environment.