Development of a Bioactive Surface on a Co-Cr-Mo Alloy during Investment Casting or Heat Treatment
Two different techniques were used to promote a bioactive surface on a cobalt base alloy: i) the cobalt alloy melt was cast into wollastonite-coated cavities of an investment mold, or ii) wollasonite-encapsulated as-cast samples were heat treated at 1220°C for 1 h, this is the typical treatment performed to this alloy for improving its mechanical behavior. In vitro bioactivity was assessed by immersing samples in a simulated body fluid for 21 days. Potentially bioactive layers were obtained in both of the cases. A thicker apatite layer was formed on the samples obtained by investment casting. However, since the heat treatment needs to be performed, the heat treatment method is also a promising technique for promoting the bone-bonding ability of this Co alloy.
Guy Daculsi and Pierre Layrolle
J. C. Ortiz-Cuellar et al., "Development of a Bioactive Surface on a Co-Cr-Mo Alloy during Investment Casting or Heat Treatment", Key Engineering Materials, Vols. 361-363, pp. 653-656, 2008