Adjustment of Aging Temperature for Reaching Superelasticity in Highly Ni-Rich Ti-51.5Ni NiTi Shape Memory Alloy

作者：Karimzadeh M; Aboutalebi M R^*; Salehi M T; Abbasi S M; Morakabati M

来源：Materials and Manufacturing Processes, 2016, 31(8): 1014-1021.

DOI：10.1080/10426914.2015.1048468

• Transformation
• Mechanical
• Superelasticity
• Deformation
• Pseudoelasticity
• Properties
• Martensitic
• Aging

In this research, the effects of aging temperature on the phase transformation, mechanical properties, and superelasticity of Ti-51.5 at.% Ni alloy were investigated. For this purpose, samples were solution annealed and then aged at different temperatures ranging from 300 to 700 degrees C. The results showed that the change of aging temperature has a great influence on the behavior of the alloy. Aging at 300 and 400 degrees C led to the occurrence of the austenite to R phase (A <-> R) transformation. By aging at these temperatures, the ultimate tensile strength and elongation did not change significantly compared to the solution annealed sample. Aging at 500 and 600 degrees C led to the appearance of B19 ' phase during cooling cycle of differential scanning calorimetry tests. Samples aged at 500 and 600 degrees C showed the best mechanical properties, in comparison with the other aging temperatures. Maximum tensile strength of 1250MPa and the elongation of 25% were obtained by aging at 500 and 600 degrees C, respectively. Solution-annealed sample showed no superelastic property. Complete superelasticity was observed by aging at 400 and 500 degrees C. The sample aged at 700 degrees C showed the transformation behavior and mechanical properties similar to the solution annealed sample.

• 出版日期2016-6-10