Microstructure and Mechanical Behavior of Ti–25Nb–25Zr Alloy Prepared from Pre-Alloyed and Hydride-Mixed Elemental Powders

Abstract

A study has been undertaken on the feasibility of the powder-metallurgy manufacturing process to fabricate β-type Ti–25Nb–25Zr alloy (mass%) for biomedical applications. The Ti–25Nb–25Zr alloy was fabricated from a mixture of TiH₂ with constituent elemental powders, and from a pre-alloyed Plasma Rotating Electrode Processed (PREP) Ti–25Nb–25Zr powder, separately. It is shown that different processing methods led to different microstructures and mechanical properties. The Ti–25Nb–25Zr compact prepared by pre-alloyed powder exhibits poor strength whereas TiH₂ processed Ti–25Nb–25Zr compact exhibits comparatively ultra-fine grained microstructure with significantly improved strength. The proposed fabrication method may have several opportunities to fabricate metallic alloys with enhanced mechanical properties.