二次退火时间对TNM合金微观组织和硬度的影响  

Effect of Secondary Annealing Duration on Microstructure and Hardness of TNM Alloy

作　　者：茶丽梅[1,3] 孙宗宗 张勇 林欣[1] 张羽 赵新奇 郝静[2] CHA Limei;SUN Zongzong;ZHANG Yong;LIN Xin;ZHANG Yu;ZHAO Xinqi;HAO Jing(College of Materials Science and Engineering,Hunan University,Changsha 410082,China;Department of Mechanical Engineering,University of Hannover Ningbo,Ningbo 315000,China;Department of Materials Science and Engineering,Guangdong Technion Israel Institute of Technology,Shantou 515063,China)

机构地区：[1]湖南大学材料科学与工程学院,湖南长沙410082 [2]宁波汉诺威大学机械系,浙江宁波315000 [3]广东以色列理工学院材料科学与工程系,广东汕头515063

出　　处：《湖南大学学报（自然科学版）》2019年第6期18-23,共6页Journal of Hunan University:Natural Sciences

基　　金：国家自然科学基金资助项目(5140020842);青年教师成长计划项目(531107040835)~~

摘　　要：研究了TNM(Ti-Al-Nb-Mo)合金中热处理条件与显微组织、力学性能的关联.将合金样品先在1 270℃下退火后,再分别于800℃保温500、1 000和2 000 h.利用X射线衍射(XRD)、扫描电子显微镜(SEM)、透射电子显微镜(TEM)和显微硬度计分析了具有不同二次退火时间样品的物相、微观形貌及显微硬度的变化.结果表明:随着退火时间的延长,(α2+γ)层片团边界逐渐粗化,界面处出现更多的βo和γ组成的网络状组织;同时在α2层片内出现更多的纳米级βo颗粒,使单个α2层片中出现α2/βo/α2结构.由于βo颗粒的硬度较大,且层片内的α2/βo界面可以阻碍位错的运动,所以TNM合金的硬度随着二次退火时间的延长而有所提高.This study focused on the inner correlation between heat treatment,microstructure and mechanical property of TNM(Ti-Al-Nb-Mo)alloy.The samples were firstly annealed at 1 270℃,then kept at 800℃for 500,1 000 and 2 000 hours,separately.Using X-ray diffraction(XRD),scanning electron microscope(SEM),transmission electron microscope(TEM)and microhardness tester,the phases,microstructures and hardness of the samples bared by varied heat treatments were investigated.It was found that the boundaries of(α2+γ)colonies were boarding when the annealing duration increased;moreβoandγparticles precipitated at colony boundaries and formed a cellular structure.At the same time,more nano-scaledβoparticles were showed up in the singleα2 lamellae,inducingα2/βo/α2 structure and more interfaces.Therefore,the hardness of TNM alloy can be enhanced with the prolonging of annealing duration due to the bigger hardness ofβoparticles andα2/βointerface which can hind dislocation movements additionally.

关 键 词：钛铝合金 热处理 硬度 微观结构 

分 类 号：TG14[一般工业技术—材料科学与工程] TG15[金属学及工艺—金属材料]