The Deformation Behavior of TiNi Shape Memory Alloy under Axial Dynamic Compression  

作　　者：黄学文 

机构地区：[1]Xi'an Jiaotong University

出　　处：《Journal of Wuhan University of Technology(Materials Science)》2004年第3期86-89,共4页武汉理工大学学报（材料科学英文版）

基　　金：FundedbytheNationalNaturalScienceFoundationofChi na (No .5 0 0 75 0 72 )andtheOpenFoundationofTribologyInstituteofSouthwestJiaotongUniversity

摘　　要：The deformation behavior of Ti-50.9at%Ni shape memory alloy under axial compression dynamic loads was investigated by an MTS 858Mini Bionix test machine. The alloy were aged at 500℃ for an hour before being machined into specimens. The compression experiments were conducted at 20℃ and the variety of dynamic loads were controlled by the strain rate, which was 3mm/min, 15mm/min, 30mm/min and 50mm/min, respectively. The experimental results indicate that in the case of 3mm/min, stress-induced martensitic transformation occurs at about 350MPa when loading and reverse transformation at about 200MPa when unloading, during which the aged Ti-50.9at%Ni alloy shows the recoverable nonlinear pseudoelastic strain of 4.3% with the residual strain of 1.2% reserved. With the strain rate increasing, the area encloses by loading-curve and unloading-curve, i.e stress (strain) hysteresis becomes smaller and smaller and the residual strain also decreases, while critical stress for inducing martensitic transformation rises. At a higher strain rate the alloy exhibits linear-like pseudoelasticity, which is up to 4.5%.The deformation behavior of Ti-50.9at%Ni shape memory alloy under axial compression dynamic loads was investigated by an MTS 858Mini Bionix test machine. The alloy were aged at 500℃ for an hour before being machined into specimens. The compression experiments were conducted at 20℃ and the variety of dynamic loads were controlled by the strain rate, which was 3mm/min, 15mm/min, 30mm/min and 50mm/min, respectively. The experimental results indicate that in the case of 3mm/min, stress-induced martensitic transformation occurs at about 350MPa when loading and reverse transformation at about 200MPa when unloading, during which the aged Ti-50.9at%Ni alloy shows the recoverable nonlinear pseudoelastic strain of 4.3% with the residual strain of 1.2% reserved. With the strain rate increasing, the area encloses by loading-curve and unloading-curve, i.e stress (strain) hysteresis becomes smaller and smaller and the residual strain also decreases, while critical stress for inducing martensitic transformation rises. At a higher strain rate the alloy exhibits linear-like pseudoelasticity, which is up to 4.5%.

关 键 词：shape memory alloy phase transformation PSEUDOELASTICITY strain rate STRESS-STRAIN 

分 类 号：TG139.6[一般工业技术—材料科学与工程]