On the Lüders band formation and propagation in NiTi shape memory alloys  

作　　者：Bashir S.Shariat Yingchao Li Hong Yang Yunzhi Wang Yinong Liu 

机构地区：[1]Department of Mechanical Engineering,The University of Western Australia,35 Stirling Highway,Perth,WA 6009,Australia [2]Department of Materials Science and Engineering,The Ohio State University,Columbus,OH 43210,USA

出　　处：《Journal of Materials Science & Technology》2022年第21期22-29,共8页材料科学技术（英文版）

基　　金：financial support from the Australian Research Council in grants DP180101744 and DP180101955;support from the US National Science Foundation under Grant DMR-1923929。

摘　　要：Near-equiatomic NiTi shape memory alloys are known to exhibit Lüders-type deformation associated with a stress-induced transformation.Many studies have been conducted in the past mainly focusing on the macroscopic characteristics of the phenomenon and some theories have been proposed in the literature to explain its mechanisms,but some aspects of this phenomenon are still unclear,particularly at the microscopic scale.This study investigated the local strain evolution during the initiation and propagation of Lüders band in a pseudoelastic NiTi alloy during tensile deformation by means of digital image correlation(DIC)analysis.Based on the evidence collected,distinct stages of Lüders band formation and propagation are defined and the corresponding local strain rates are obtained.These local strain rates are much higher than the global strain rate of the testing,giving insight to the mechanism of this phenomenon.

关 键 词：Shape memory alloy(SMA) NITI Martensitic transformation Lüders-type deformation Lüders band Digital image correlation(DIC) 

分 类 号：TG139.6[一般工业技术—材料科学与工程]