Evaluation of the Shape Memory Effect by Micro-Compression Testing of Single Crystalline Ti-27Nb Ni-Free Alloy

• Main Authors: Takashi Nagoshi, Takahisa Yasuda, Nao Otaki, Masaki Tahara, Hideki Hosoda, Masato Sone
• Format: Article
• Language: English
• Published: MDPI AG 2019-12-01
• Series: Materials
• Subjects: shape memory alloy; temperature variable micro-compression test; single crystal; biomedical alloy
• Online Access: https://www.mdpi.com/1996-1944/13/1/110

In this work, micro-compression tests are performed at various temperatures with Ti-27Nb (at.%) single crystalline pillars to investigate anisotropic deformation behavior, including the shape memory effect. In non-tapered single-crystal pillars with loading directions parallel to [001], [011], and [111], transformation strain and stress show orientation dependence. [001]-oriented micropillars with aspect ratios of 2 and 1.5 demonstrate temperature-dependent transformation stress during micro-compression at various temperatures. Although more stress is required to induce martensite transformation in the pillar with the lower aspect ratio, the temperature dependence of ~1.8 MPa/K observed in both pillars is in good agreement with that of bulk Ti-27Nb.