Effect of Zr additions on mechanical properties of an ASTM F-75 alloy

Abstract

The ASTM F-75 alloy is widely used for orthopedic implants. In order to improve the mechanical properties, in particular ductility, the components fabricated by the investment casting process are generally heat treated to partially dissolve carbide precipitates. In the present work, the effect of Zr additions on the mechanical properties of a solution-treated ASTM F-75 alloy was studied. The Zr contents were 0.1, 0.05, 0.017, and 0%. Among the alloys chemically modified, that with 0.017% of Zr provided an appropriate microstructure for thermal processing. After the solution treatment, the latter alloy showed markedly increased tensile properties when compared with the Zr-free alloy. This was associated to the role of Zr as a grain refiner, as revealed by the microstructural analysis. Thus, the addition of Zr constitutes an effective way to enhance the mechanical properties of solution-treated alloys.