热机械处理中退火时间对Fe-Mn-Si基合金形状记忆效应的影响  

Influence of annealing time on shape memory effect of an Fe-Mn-Si based alloy during thermo-mechanical treatment

作　　者：左阳 孙礼鑫 宋帆 彭华备[1] 陈聪[2] 文玉华[1] ZUO Yang;SUN Lixin;SONG Fan;PENG Huabei;CHEN Cong;WEN Yuhua(School of Mechanical Engineering,Sichuan University,Chengdu 610065,China;Science and Technology on Reactor System Design Technology Laboratory,Nuclear Power Institute of China,Chengdu 610213,China)

机构地区：[1]四川大学机械工程学院,成都610065 [2]中国核动力研究设计院核反应堆系统设计技术重点实验室,成都610213

出　　处：《材料工程》2023年第5期87-93,共7页Journal of Materials Engineering

基　　金：国家自然科学基金项目(51171123)。

摘　　要：热机械处理能显著改善Fe-Mn-Si基合金的形状记忆效应。本工作中,对铸态Fe-Mn-Si基合金进行热锻、20%冷轧变形及固溶处理,随后在1073 K对部分经10%室温拉伸变形的试样进行不同时间退火处理。借助背散射电子显微分析(EBSD)、RGM-4300型万能试验机、示差四端电阻法及弯曲法研究热机械处理中退火时间对Fe-Mn-Si基合金微观组织和形状记忆效应的影响规律。结果表明:固溶态Fe-Mn-Si基合金的可恢复应变为4.1%;当经过退火时间为10 min的热机械处理后,合金的可恢复应变显著提高至5.3%;当进一步延长热机械处理的退火时间,合金的可恢复应变随之下降;当热机械处理的退火时间为180 min时,合金的可恢复应变下降至4.9%。随着热机械处理的退火时间延长,退火孪晶分数增加,堆垛层错密度下降,从而导致Fe-Mn-Si基合金促进应力诱发ε马氏体相变和抑制塑性滑移的能力变弱。这是Fe-Mn-Si基合金的可恢复应变随着热机械处理的退火时间延长而降低的主要原因。The shape memory effect of Fe-Mn-Si based alloys could be significantly improved by thermo-mechanical treatments.In this work,the cast Fe-Mn-Si based alloy was hot forged,20%cold rolled and solution treated,followed by annealing at 1073 K for different time on some specimens deformed by 10%at room temperature,and the effect of annealing time of thermo-mechanical treatments on the microstructures and shape memory effect of the Fe-Mn-Si based alloy was studied with the help of backscattered electron microanalysis(EBSD),RGM-4300 universal testing machine,differential four-terminal resistance method and bending method.Results show that the recovery strain of the solution-treated Fe-Mn-Si based alloy is 4.1%;when the annealing time of thermo-mechanical treatment is 10 min,the recovery strain is remarkably improved to 5.3%;As the annealing time of thermo-mechanical treatment is further prolonged,the recovery strain decreases;when the annealing time of thermo-mechanical treatments is 180 min,the recovery strain decreases to 4.9%.As the annealing time of thermo-mechanical treatments prolongs,the fraction of annealing twins increases,while the density of stacking faults decreases,which leads to the ability of facilitating stress-inducedεmartensitic transformation and suppressing plastic glide weakening.This is the main reason why the recovery strain of the Fe-Mn-Si based alloy decreases with the annealing time of thermo-mechanical treatments prolonging.

关 键 词：形状记忆合金 热机械处理 退火孪晶 堆垛层错 

分 类 号：TG1[金属学及工艺—金属学]