Ti-6Cr-5V-5Mo-4Al-1Nb合金的晶粒长大动力学  

Grain Growth Kinetics of Ti-6Cr-5V-5Mo-4Al-1Nb Alloy

作　　者：宋越 崔雪飞 于洋[1,2,3] 宋晓云 叶文君[1,2,3] 惠松骁 Song Yue;Cui uefei;Yu Yang;Song Xiaoyun;Ye Wenjun;Hui Songxiao(State Key Laboratory of Nonferrous Metals and Processes,GRINM Group Co.,LTD.,Beijing 100088,China;GRIMAT Engineering Institute Co.,LTD.,Beijing 101407,China;General Research Institute for Nonferrous Metals,Beijing 100088,China;AECC Guizhou Liyang Aviation Power Co.,LTD.,Guiyang 550014,China)

机构地区：[1]有研科技集团有限公司,有色金属材料制备加工国家重点实验室,北京100088 [2]有研工程技术研究院有限公司,北京101407 [3]北京有色金属研究总院,北京100088 [4]中国航发贵州黎阳航空动力有限公司,贵州贵阳550014

出　　处：《稀有金属》2023年第6期908-914,共7页Chinese Journal of Rare Metals

基　　金：国家重点研发计划项目(2017YFB0306204)资助。

摘　　要：以新型亚稳β钛合金Ti-6Cr-5V-5Mo-4Al-1Nb为研究对象,对其晶粒长大动力学进行研究。用Beck方程描述了晶粒的长大过程,用Arrhenius方程计算了晶粒长大激活能,对晶粒尺寸的均匀性(ω值)随固溶温度与时间的变化规律进行了总结并进行相关机制分析,得到了合金适宜的固溶温度区间。研究表明:Ti-6Cr-5V-5Mo-4Al-1Nb合金在890℃以下固溶时,晶粒的尺寸稳定性较好;而在890℃以上热处理,晶粒急剧粗化,故该合金适宜的固溶温度在890℃以下。且随着固溶时间的延长,晶粒的长大速度减缓。固溶后ω值随时间的延长先降低又逐渐升高,而且温度越高达到ω最小值的时间越短,晶粒尺寸的均匀性越差。合金的生长指数(n值)随温度升高而增大,范围在0.22~0.39之间,均小于纯钛在相变点上保温时的生长指数,这是由于该材料合金化程度高,大量的溶质原子形成的杂质气团会对晶界的迁移产生阻碍作用。晶粒长大激活能随着保温时间的延长而增加,其值在46.2~100.6 kJ·mol^(-1)之间。Because of its excellent specific strength,hardenability and heat treatment strengthening effect,metastable β titanium alloy has become the key material for some structural parts such as fasteners and frames of aircraft.For metastable β titanium alloy,a suitable solution treatment process above the β phase transition point can obtain metastable microstructure,which lays the organizational foundation for the subsequent aging strengthening treatment of the material.However,due to the cubic structure of titanium alloy in β phase region,the diffusion of β phase is enhanced,and the grains are easy to grow.In addition,the grain size is also closely related to the fracture toughness of titanium alloy.When the crack propagates along the grain boundary,if the grain size is too large or too small,the path will be straighter.Only the appropriate grain size can make the crack path tortuous,so that the alloy can obtain excellent fracture toughness.Therefore,in-depth study of grain growth behavior and growth mechanism is the premise of designing and regulating process parameters,and then obtaining excellent mechanical properties.In this paper,a new metastable β titanium alloy Ti-6Cr-5V-5Mo-4Al-1Nb was taken as the research object.At present,there were few reports on the matching of strength and toughness of the alloy.The fracture toughness of titanium alloy was closely related to grain size,so in this paper,the grain growth kinetics of the alloy during solid solution in β single phase region was studied from the perspective of grain size influencing factors.According to the grain growth mechanism of the alloy,theoretical reference was provided for the formulation of solid solution process parameters of the alloy,so as to obtain excellent strength and toughness matching of the alloy and broaden the engineering application range of the alloy.After solid solution treatment of new metastable β titanium alloy,coarse grinding,fine grinding and polishing were carried out to make metallographic samples.The microstructure evolu

关 键 词：亚稳Β钛合金 晶粒长大动力学 长大激活能 晶粒均匀性 

分 类 号：TG146.23[一般工业技术—材料科学与工程]