Comparing the mechanical properties, microstructure, texture and in-vitro degradation behavior of TNTZ/nano-fluorapatite composite and TNTZ bioalloy.

Abstract

The present study deals with (i) the fabrication of the composite surface layer of Ti-29Nb-13Ta-4.6Zr/nano-fluorapatite through friction stir processing, (ii) clarifying the correlation of microstructure and texture with in-vitro degradation behavior and bioactivity of fabricated nano-biocomposite, and (iii) comparing the mechanical and functional properties of nano composite whit those obtained for TNTZ bio-alloy. The results indicated that increasing the number of deformation passes effectively refines the microstructure, leading to the average grain sizes of less than 5 μm. The texture of the material was also evolved in the presence of the nano particles where the grains reorient along <111> direction in contrast to the <101>-oriented grains in the starting microstructure. In-vitro bioactivity of the processed samples was measured after being immersed in simulated body fluid solution for various duration up to 30 days. Enhanced corrosion resistance and bio-mineralization of nanocomposite surface layer was discussed relying on the occurrence of grain refinement, substructure development and evolution of texture components along <101> direction. Assessment of the mechanical properties of the fabricated composites and as-received material also indicated the positive effect of the applied processing route and the presence of nano particles.