The Influence of Nb Content on Phase Formation and Compressive Strength of Ti-Nb Alloy Produced via Powder Metallurgy Route

摘要

In this research, the influence of Nb content in Ti-Nb alloy system produced by powder metallurgy (PM) route on beta phase formation and mechanical strength was observed. The experimental work comprised of mixing of elemental niobium (Nb) and titanium (Ti) powders, ranging from 30 to 45 wt% Nb, followed by cold compaction at room temperature and sintering in high vacuum furnace at 1200°C. All samples were characterized by X-Ray Diffraction (XRD) and Scanning Electron Microscope (SEM) for phase constituents and microstructures, respectively. The mechanical strength was then evaluated by monotonic compression test. Results showed that increasing the Nb content would increase the beta-phase intensity which was supported by the SEM microstructure; an increase of beta-phase fraction in the matrix. The lowest mechanical strength was observed in 45 wt% Nb owing to partly crystallized region with some inclusions in the microstructure, particularly at Nb particle region. The alloy of 40 wt% Nb exhibited better beta-phase homogeneity structures in the matrix which resulted from optimum diffusion between Ti and Nb particles during sintering. The Young’s Modulus obtained for all alloy compositions were in the range of 13 and 19 GPa, seems to be promising candidate as bio-metallic implant application.