LAUSR

Abstract A series study of the ternary near–eutectoid Ti–Au–Cr shape memory alloys (SMA) at the Ti–rich corner was explored in this work towards the applications of biomedical materials. Fundamental analysis, such as microstructures, phase constitutions, lattice parameters, and mechanical properties of the specimens, were examined along with their functional properties, such as shape memory effect (SME) and superelasticity (SE). Most of the alloys possess good cold–workability except for those with great amounts of precipitates of the brittle Ti3Au at the high Au addition specimens. The Ti–4Au–8Cr alloy excelled in strength while the Ti–2Au–8Cr alloy surpassed other alloys in ductility. Most of the specimens possess SME as well as pseudoelasticity and/or superelasticity indicating the functionality of the Ti–Au–Cr alloys towards biomedical applications. The discrimination between the α′–martensite phase and the α′′–martensite phase was conducted by the TEM observation. The α′–martensite phase, which unexpectedly performed SME in this study was determined to locate exactly at the boundary of the α′–martensite regime and the α′′–martensite regime. The SME of the alloys, which were composed of the α′–martensite phase, were thus deduced to originate from the similarity of the α′–martensite and the α′′–martensite.