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

The ASTM F-75 alloy is widely used for orthopedic implants. In order to imp rove the mechanical properties, in particular ductility, the components fab ricated by the investment casting process are generally heat treated to par tially dissolve carbide precipitates, In the present work, the effect of Zr additions on the mechanical properties of a solution-treated ASTM F-75 all oy was studied. The Zr contents were 0.1, 0.05, 0.017, and 0%. Among the al loys chemically modified, that with 0.017% of Zr provided an appropriate mi crostructure for thermal processing. After the solution treatment, the latt er alloy showed markedly increased tensile properties when compared with th e 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 const itutes an effective way to enhance the mechanical properties of solution-tr eated alloys.