Ti-62A钛合金多道次降温热变形行为研究  

Hot Deformation Behavior of Ti-62A Titanium Alloy after Multi-Step Cooling

作　　者：丁凯伦 王敬忠[1,2] 杨西荣[1,2] 刘晓燕[1,2] 罗雷[1] 李磊[3] Ding Kailun;Wang Jingzhong;Yang Xirong;Liu Xiaoyan;Luo Lei;Li Lei(School of Metallurgy and Engineering,Xi'an University of Architecture and Technology,Xi'an 710055,China;Shaanxi Metallurgical Engineering Technology Research Center,Xi'an University of Architecture and Technology,Xi'an 710055,China;Titanium Alloy Research Institute,Northwest Institute for Non-ferrous Metals Research,Xi'an 710016,China)

机构地区：[1]西安建筑科技大学冶金工程学院,陕西西安710055 [2]西安建筑科技大学陕西冶金工程技术研究中心,陕西西安710055 [3]西北有色金属研究院钛合金研究所,陕西西安710016

出　　处：《稀有金属》2021年第8期921-927,共7页Chinese Journal of Rare Metals

基　　金：国家自然科学基金项目(51474170)资助。

摘　　要：在Gleeble-3800型热模拟机上对Ti-62A合金进行了不同变形参数的多道次热模拟试验,利用金相显微镜和透射电子显微镜观察了Ti-62A合金多道次降温条件下材料的变形及微观组织演化行为。结果表明:流变应力随着变形温度的降低呈阶梯升高,变形温度对Ti-62A合金的弹性模量几乎没有影响;β单相区变形过程中动态回复为主要软化机制,α+β双相区变形,主要的软化机制为次生α相的部分动态再结晶和形变诱导的β→α相的转变;微观组织均由β基体和不同取向的次生α相构成。随着压缩道次的增加,次生α相从细小致密的针状变为粗大的片层状,并与晶界成一定角度。次生针状α相在晶界处形核,向晶粒内部生长,使原β晶界破碎。随着变形道次增加和变形温度降低,合金中次生α相分布规律性变差。经1050-1010℃温度区间变形,β相基体内部的针状α相呈相互垂直关系,构成网格形态;而经1050-930℃温度区间变形,晶内仅出现一种相互平行的片层状α相变体。Controlling the deformation process of metal materials was one of the key links to obtain excellent mechanical properties.However,the research on Ti-62 A alloy was still limited in the aspects of heat treatment processes and mechanical properties,and there was no report on using multi-pass hot compression deformation to simulate the rolling production of Ti-62 A alloy. Therefore,it was necessary to reveal the multi-pass hot deformation behavior and microstructure evolution of Ti-62 A alloy. In order to provide theoretical support and technical reference for the actual production process of Ti-62 A alloy,the effect of step by step hot compression deformation on the flow stress and microstructure evolution of Ti-62 A alloy was studied. Multi-pass thermal simulation tests of Ti-62 A alloy with different deformation parameters were carried out on Gleeble-3800 thermal simulator. The deformation and microstructure evolution of Ti-62 A alloyed under multi-pass cooling conditions were observed by metallographic microscope and transmission electron microscope(TEM). The results showed that the flow stress increased step by step with the decrease of deformation temperature,and the peak deformation resistance at 890 ℃ was twice that at 1050 ℃,which indicated that the decrease of temperature led to the increase of deformation resistance of the alloy,but on the whole,the resistance of high temperature deformation of Ti-62 A alloy was smaller,that was to say,the alloy was easier to achieve deformation. Each pass had an elastic deformation stage in which the stress increased linearly with the strain,and there was almost no difference in the slope of this stage,which indicated that the deformation temperature had no obvious effect on the initial elastic modulus of Ti-62 A,and there was no obvious difference between the elastic modulus of single phase β region and that of α+β dual phase region. With the increase of cumulative deformation,the residence time between passes was short,which was not enough to make the distortion

关 键 词：Ti-62A合金 多道次热压缩变形 微观组织演变 流变应力 

分 类 号：TG146.23[一般工业技术—材料科学与工程]