基于响应面法的NiTi形状记忆合金热成形工艺参数优化  

Optimization of hot forming process parameters of NiTi shape memory alloy based on response surface method

作　　者：王俊[1] 王克鲁[1] 鲁世强[1] 李鑫[1] 欧阳德来[2] 高鑫 张开铭 WANG Jun;WANG Ke-lu;LU Shi-qiang;LI Xin;OUYANG De-lai;GAO Xin;ZHANG Kai-ming(School of Aerospace Manufacturing Engineering,Nanchang Hangkong University,Nanchang 330063,China;School of Materials Science and Engineering,Nanchang Hangkong University,Nanchang 330063,China)

机构地区：[1]南昌航空大学航空制造工程学院,江西南昌330063 [2]南昌航空大学材料科学与工程学院,江西南昌330063

出　　处：《塑性工程学报》2022年第6期157-164,共8页Journal of Plasticity Engineering

基　　金：国家自然科学基金资助项目(51761029);南昌航空大学研究生创新专项基金资助项目(YC2020026)。

摘　　要：在变形温度为650~950℃、应变速率为0.001~10 s^(-1)和最大下压量为70%的条件下,采用Gleeble-3500热模拟试验机对NiTi形状记忆合金进行了等温恒应变速率压缩实验。基于实验数据分析了NiTi形状记忆合金的流变应力曲线,计算出不同工艺参数下材料的热变形激活能、Z参数和功率耗散系数,建立了基于响应面法的工艺参数和各材料参数间的预测模型,最后对响应面模型进行了多目标可视优化,得到了优化后的工艺参数。结果表明:在应变速率为0.1 s^(-1)下,当变形温度为650~750℃时,流变应力曲线呈动态软化特征,当变形温度为800~950℃时,流变应力曲线呈稳态流动特征。基于响应面法建立的预测模型具有较高的精度,优化后的工艺参数范围为650~870℃、0.001~0.006 s^(-1)。经组织分析验证,该区域主要的变形机制为动态回复。The isothermal compression experiments with constant strain rate of NiTi shape memory alloy were carried out by Gleeble-3500 thermal simulator at deformation temperature of 650-950℃,strain rate of 0.001-10 s^(-1) and the maximum reduction of 70%.The flow stress curves of NiTi shape memory alloy were analyzed based on the experimental data,and the hot deformation activation energy,Z parameter and power dissipation coefficient of material with different process parameters were calculated.The prediction model between process parameters and each material parameter based on response surface method was established.Finally,the visualization optimization for the response surface model was carried out,and the optimized process parameters were obtained.The results show that with the strain rate of 0.1 s^(-1),the flow stress curves show dynamic softening characteristics when the deformation temperature is 650-750℃,and the flow stress curves show steady flow characteristics when the deformation temperature is 800-950℃.The prediction model established based on response surface method has high accuracy,and the optimized process parameters range is 650-870℃,0.001-0.006 s^(-1).The main deformation mechanism in this zone is dynamic recovery,which is verified by the microstructure analysis.

关 键 词：NITI形状记忆合金 流变应力曲线 热变形激活能 响应面法 工艺参数优化 

分 类 号：TG146.23[一般工业技术—材料科学与工程]