Effect of rolling temperature and reduction on brick-and-mortar Ti2Ni/TiNi composite
(1. National Key Laboratory of Science and Technology on Materials under Shock and Impact, Beijing Institute of Technology, Beijing 100081, China;
2. Tangshan Research Institute, Beijing Institute of Technology, Tangshan 063000, China)
2. Tangshan Research Institute, Beijing Institute of Technology, Tangshan 063000, China)
Abstract: The brick-and-mortar Ti2Ni/TiNi composite, composed of Ti2Ni bricks distributed among TiNi mortars, was successfully produced by hot rolling laminated Ti2Ni/TiNi composite. The rolling temperature and reduction have large effects on brick width and brick interspacing, respectively. When the compression is carried out perpendicular to the stacking direction, all the samples exhibit delamination fracture, which is harmful to mechanical performances. When loading is parallel to the stacking direction, too large brick width and too small brick interspacing both boost the delamination between brittle Ti2Ni and ductile TiNi. After 60% rolling at 700 °C, the brick-and-mortar composite exhibits a largest strength of (1923.11±70.78) MPa and a largest fracture strain of 0.190±0.017 because suitable brick width and interspacing inhibit the delamination and promote crack deflection. Further optimization of mechanical properties can be achieved by the adjustment of brick width and interspacing.
Key words: brick-and-mortar structure; TiNi; delamination; rolling