Possibility of bulk glassy and nanogranular alloys as biomedical materials

Abstract

This paper reviews our recent results on the formation, fundamental properties and application examples of nanogranular body-centered cubic (bcc) Ti-based alloys, bulk glassy Ti-based alloys and porous Pd- and Zr-based glassy alloys with the aim of clarifying the possibility of practical uses as biomedical materials. The bcc Ti-based alloys with low Young’s modulus, large elastic elongation and high mechanical strength have already been used as eyeglass frame materials. New Ti-based bulk glassy alloys with a critical diameter of 7 mm in Ti-Zr-Cu-Pd system have been developed and tested as artificial dental root materials in various environmental conditions. The Pd- and Zr-based bulk glassy alloys can include spherical or polyhedral pores in a wide porosity range. The porous bulk glassy alloys have unique mechanical properties which are comparable to bones of human beings. These results indicate the possibility that the present nanogranular bcc Ti-based alloys as well as the bulk glassy alloys in Ti-, Pd- and Zr-based systems are used as biomedical materials in the near future.