Microstructure, mechanical and biological properties of zirconium alloyed with niobium after severe plastic deformation

Abstract

Abstract A comparative investigation of microstructure, mechanical and biological properties for zirconium alloyed with niobium in coarse‐grained and ultra‐fine grained states is presented. The temperature and deformation regimes of multi‐stage abc‐pressing resulted in ultra‐fine grained states with an average size of the structural elements in the range of 0.28–0.55 μm, depending on the accumulated strain during pressing. The increase of the accumulated strain at each stage of pressing increased the uniformity of the structure. The microhardness increased by 50% with increased accumulated strain during the severe plastic deformation. Between the microhardness and the average size of the structural elements, a linear dependence was found, indicating a Hall‐Petch relationship. The alloy had a good biocompatibility as shown by an MTT test with osteoblasts (MG‐63 cell line). The good mechanical properties (microhardness) of zirconium alloyed with niobium in the ultra‐fine grained state make it suitable for medical applications, e. g. as implant material.