Comparative study on Ti-Nb binary alloys fabricated through spark plasma sintering and conventional P/M routes for biomedical application

摘要

The main purpose of this work is to obtain homogenous, single beta phase in binary Ti-xNb (x = 18.75, 25, and 31.25 at.%) alloys by simple mixing of pure elemental powders using different sintering techniques such as spark plasma sintering (pressure-assisted sintering) and conventional powder metallurgy (pressure-less sintering). Synthesis parameters such as sintering temperature and holding time etc. are optimized in both techniques in order to get homogenous microstructure. In spark plasma sintering (SPS), complete homogeneous beta phase is achieved in Ti25at.%Nb using 1300 degrees C sintering temperature with 60 min holding time under 50 MPa pressure. On the other hand, complete beta phase is obtained in Ti25at.%Nb through conventional powder metallurgy (P/M) route using sintering temperature of 1400 degrees C for 120 min holding time which are adopted from the dilatometry studies. Nano-indentation is carried out for mechanical properties such as Young's modulus and nano-hardness. Elastic properties of binary Ti-xNb compositions are fallen within the range of 80-90 GPa. Cytotoxicity as well as cell adhesion studies carried out using MG63, osteoblast-like cells showed excellent biocompatibility of thus developed Ti25at.%Nb surface irrespective of fabrication route.