Adjustment of Aging Temperature for Reaching Superelasticity in Highly Ni-Rich Ti-51.5Ni NiTi Shape Memory Alloy. Issue 8 (10th June 2016)

• Record Type: Journal Article
• Authors: Karimzadeh, M.; Aboutalebi, M. R.; Salehi, M. T.; Abbasi, S. M.; Morakabati, M.
• Is Part Of: Materials and manufacturing processes. Volume 31:Issue 8(2016)
• Page Start: 1014
• Page End: 1021
• Publication Date: 2016-06-10
• Subjects: Aging -- Deformation -- Martensitic -- Mechanical -- Properties -- Pseudoelasticity -- Superelasticity -- Transformation; Manufacturing processes -- Periodicals; Materials -- Periodicals; Manufactured Materials; 670.5
• DOI: 10.1080/10426914.2015.1048468
• Languages: English
• ISSNs: 1042-6914

Abstract

Abstract : 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°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°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°C led to the appearance of B19′ phase during cooling cycle of differential scanning calorimetry tests. Samples aged at 500 and 600°C showed the best mechanical properties, in comparison with the other aging temperatures. Maximum tensile strength of 1250 MPa and the elongation of 25% were obtained by aging at 500 and 600°C, respectively. Solution-annealed sample showed no superelastic property. Complete superelasticity was observed by aging at 400 and 500°C. The sample aged at 700°C showed the transformation behavior and mechanical properties similar to the solution annealed sample.