Mechanical Properties of Nano-Structure Controlled Ti-Hf Alloy for Dental

Ti-Hf alloy system forms an α-β isomorphous system and does not form any intermetallic compounds, which is also beneficial for good mechanical properties. The aim of this study was the improvement of mechanical property and biocompatibility by Hf addition to Ti-alloy. Ti-Hf(10, 20, 30 and 40wt%) alloys manufactured by non consumable vacuum arc melting furnace. All the specimens were nanostructure controlled by heat treatment at 1000 °C for 24hr in Ar atmosphere followed by furnace cooling and quenching into 0°C water. Phase constitutions, microstructure, and mechanical properties of the samples were characterized by XRD, OM, SEM, EDX. micro-hardness test and tensile test. Lamellar structure was transformed to needle-like structure with increased Hf contents. The α-phase peaks were detected for all samples. Hardness and tensile strength of Ti-Hf alloy increased as Hf content increased in the case of both water quenched and furnace cooled sample. Especially, the hardness and tensile strength of water quenched Ti40Hf alloy was higher than that of others due to formation of needle-like structure.