摘要
采用Gleeble-3800型热模拟试验机在变形温度为700~850℃、应变速率为0.001~1 s^(-1)条件下对SP700钛合金进行等温恒应变速率压缩试验,分析SP700钛合金的热变形行为。首次探讨了该合金考虑变形温度对杨氏模量和自扩散系数影响的传统物理本构关系以及考虑晶界扩散和晶格扩散耦合的修正物理本构关系。结果表明,SP700钛合金的流动应力曲线为典型的动态再结晶型曲线,其流动应力随应变速率的降低和变形温度的升高而减小;传统物理本构关系和修正的物理本构关系相关系数R分别为0.986和0.965,平均相对误差AARE分别为14.4%和13.1%,说明建立的两个物理本构关系都能较好地表征该合金的流动应力行为。另外,确定了该合金在700~800℃热变形时主要扩散机制是晶界扩散,在850℃热变形时主要是晶格扩散。
SP700 titanium alloy was subjected to isothermal and constant strain rate compression experiment at deformation temperature of 700~850℃and strain rate of 0.001~1 s^(-1)by Gleeble-3800 thermal simulation testing machine.The hot deformation behavior of SP700 titanium alloy was analyzed,and the traditional physical constitutive relationship considering the effect of deformation temperature on Young's modulus and self-diffusion coefficient and the modified physical constitutive relationship considering the coupling of grain boundary diffusion and lattice diffusion were discussed for the first time.The results indicate that the flow stress curves of SP700 titanium alloy are typical dynamic recrystallization,and flow stress is decreased with the decrease of strain rate and the increase of deformation temperature.The correlation coefficients R of the traditional and modified physical constitutive relations are 0.986 and 0.965,and the average relative errors AARE are 14.4%and 13.1%,respectively,indicating that both established physical constitutive relations can better characterize the flow stress behavior of the alloy.Meanwhile,it is also determined that the main diffusion mechanism of the alloy is grain boundary diffusion at 700~800℃hot deformation,and lattice diffusion at 850℃hot deformation.
作者
张开铭
王克鲁
鲁世强
李鑫
高鑫
邱仟
Zhang Kaiming;Wang Kelu;Lu Shiqiang;Li Xin;Gao Xin;Qiu Qian(School of Aeronautical Manufacturing Engineering,Nanchang Hangkong University)
出处
《特种铸造及有色合金》
CAS
北大核心
2023年第5期634-640,共7页
Special Casting & Nonferrous Alloys
基金
江西省自然科学基金资助项目(20202ACBL204001)
江西省研究生创新专项基金资助项目(YC2021S675)。
关键词
SP700钛合金
物理本构关系
热变形
扩散机制
SP7oo Titanium Alloy
Physical Constitutive Relation
Hot Deformation
Diffusion Mechanism
