Hot deformation behavior of Ni50.4Ti34.6Hf15 high-temperature shape memory alloy

• DOI: 10.1016/j.jmrt.2023.12.084
• Publication Date: 2023-12-12T07:53:46Z
• Authors: Muchi Jiang; Xiao Chen; Hasfi F. Nurly; Xingyuan Yang; Yi Liu; Yusheng Cai; Dechun Ren; Haibin Ji; Jiafeng Lei
• Keywords: Dynamic Recrystallization; Flow stress; Atmospheric temperature range

Due to their extreme requirements, conventional Ni–Ti shape memory alloys (SMAs) are no longer suitable for aerospace applications. Adding Hf SMAs can significantly enhance suitability applications, particularly in high-temperature environments. In this regard, the hot/thermal deformation behavior of Ni50.4Ti34.6Hf15 (HTSMAs) was systematically investigated by using a Gleeble-3800 thermocompression simulation machine. The results prove that have more strain sensitivity than temperature during process. detail, flow stress increases with increase rate and decreases temperature. From microstructure evolution point view, recovery effect will temperature, recrystallization rate. Following obtained stress-strain curves, established. A modified constitutive equations model proposed careful consideration It found calculated activation energy 363.945 kJ/mol range 700∼800 °C 512.489 900∼1000 °C. Based on equation, values were consistent experimental values, which indicated reliable analysis high prediction accuracy. Furthermore, thermal processing maps under different conditions constructed, it determined optimum parameters 940∼1000 0.01–0.04 s−1.