High temperature strain glass in Ti–Au and Ti–Pt based shape memory alloys* *Project supported by China Postdoctoral Science Foundation (Grant No. 2019M650880), the National Natural Science Foundation of China (Grant Nos. 51901243, 61888102, and 11790291), the Natural Science Foundation of Guangdong Province, China (Grant No. 2019B030302010), and the Strategic Priority Research Program of the Chinese Academy of Sciences (Grant No.

Abstract

Strain glass is a frozen short-range strain ordered state found in shape memory alloys recently, which exhibits novel properties around the ideal glass transition temperature T 0. However, the T 0 of current strain glass systems is still very low, limiting their potential applications and experimental studies. In this paper, we reported two new strain glass systems with relatively high T 0. In Ti50Au50−x Cr x alloys, the strain glass appears at x = 25, and exhibits a T 0 of 251 K, while in Ti50Pt50−y Fe y alloys, the strain glass takes place at y = 30, and shows a T 0 of 272 K. Both of them are comparable with the highest T 0 value reported so far. Moreover, the phase diagrams of main strain glass systems in Ti-based alloys were summarized. It is found that the influence of the martensitic transformation temperature of the host alloy on the T 0 of the strain glass is limited. This work may help to design new strain glass systems with higher T 0 above ambient temperature.