Exploiting ultra-large linear elasticity over a wide temperature range in nanocrystalline NiTi alloy

• 作者: Zhen Sun Shijie Hao Genfa Kang Yang Ren Junpeng Liu Ying Yang Xiangguang Kong Bo Feng Cheng Wang Kun Zhao Lishan Cui
• 来源期刊: 材料科学技术（英文版）
• 年，卷（期）: 2020,（22）
• 页码范围: 197-203
• 页数: 7页
• 语种: 英文

摘要

Many shape memory alloys can support large recoverable strains of a few percent by reversible stress-induced martensite transformation,yet they behave non-linear within a narrow operating temperature range.Developing the bulk metallic materials with ultra-large linear elasticity over a wide temperature range has proven to be difficult.In this work,a material design concept was proposed,that is true elastic deformation and reversible twinning-detwinning deformation run in parallel to overcome this challenge.By engineering the residual internal stress to realize the concurrency of true elastic deformation and twinning-detwinning deformation,a bulk nanocrystalline NiTi that possesses an ultra-large linear elastic strain up to 5.1 ％ and a high yield stress of 2.16 GPa over a wide temperature range of 270 ℃ was developed.This study offers a new avenue for developing the metallic materials with ultra-large linear elasticity over a wide temperature range of 270 ℃ (from 70 ℃ to-197 ℃).