Effect of ageing treatment on microstructure and mechanical properties of α+β type titanium alloy used for biomaterials

Abstract

The high strength Ti-Al-V alloy is a α+β type that could be extensively used for many special applications like health care instruments owing to their unique combination of better mechanical properties, superior biocorrosion resistance with excellent biocompatibility, and aerospace applications. This high strength titanium alloy system has a combination of α+β stabilizing elements such as aluminium 7.18 wt.%, and vanadium 7.69 wt.% with high nitrogen content. But special purpose of nitrogen content is α stabilizer that acts as solid solution strengthener, enhancement of mechanical properties and increasing the strain (ε) of this alloy. This experimental work has been dealt with the results of influencing the microstructure of as-received titanium alloy by solution treatment at 860oC for 1h followed by immediately quenching into oil (STQoq) and water (STQwq). These solution treated alloys were preferred for ageing at 500oC for 5h then air cooling (STA). The heat treated alloy was examined likely to OM, SEM, Vicker’s hardness measurement and tensile testing. The optimum tensile properties have been achieved after STQwq+STA treatment such as YS 915 MPa, UTS 1234 MPa, Strain (ε) 40%, RA 18.34%, and YS to UTS ratio of 0.74, respectively.