TC17(α+β)/TC17(β)线性摩擦焊接过程中焊合区组织及其织构演变  

Microstructure and Texture Evolution of the Weld Zone during Linear Friction Welding between TC17(α+β)and TC17(β)

作　　者：杜随更[1] 刘冠翔 陈虎 胡弘毅 李菊 DU Suigeng;LIU Guanxiang;CHEN Hu;HU Hongyi;LI Ju(Key Laboratory of High Performance Manufacturing for Aero Engine(Northwestern Polytechnical University),Ministry of Industry and Information Technology,Xi’an 710072;Aeronautical Key Laboratory for welding and Joining Technologies,AVIC Manufacturing Technology Institute,Beijing 100024)

机构地区：[1]西北工业大学航空发动机高性能制造工信部重点实验室,西安710072 [2]中国航空制造技术研究院航空焊接与连接技术航空科技重点实验室,北京100024

出　　处：《机械工程学报》2024年第2期99-106,共8页Journal of Mechanical Engineering

基　　金：国家科技重大专项(2017-Ⅶ-0005-0098);国家自然科学基金(10477017)资助项目。

摘　　要：线性摩擦焊接是制造异种或异质合金整体叶盘的关键技术。焊接过程中焊合区的组织形成与变化规律决定了焊接接头的组织和性能,也是线性摩擦焊接连接机理的主要研究内容。通过扫描电镜、电子背散射衍射等观察分析了TC17(α+β)/TC17(β)同种异质钛合金线性摩擦焊接过程中不同时刻停振得到的焊接接头组织,研究了焊接过程中热力影响区范围的变化规律、焊合区的动态再结晶及织构变化规律。结果表明,摩擦时间仅为0.5 s时,焊接界面中心区已发生了动态再结晶,生成了亚稳定β晶粒。随摩擦时间加长,乃至停振顶锻之后,细晶区宽度逐渐变窄,晶向分布越来越集中,小角度晶界占比增加,大角度晶界角度占比减小,动态再结晶晶粒面积逐渐加大。焊合区最终形成了与体心立方三种滑移系相对应的三种织构,{112}<111>、{110}<111>和{123}<111>。该织构形成的主要作用机制是摩擦压力,而非摩擦剪力。当接头承受轴向拉力时,该织构晶粒容易产生剪切塑性变形,降低接头强度。Linear friction welding(LFW)is a key manufacture technology for dissimilar materials and dissimilar quality materials blisk.The microstructure and properties of the welded joint are determined by the formation process and mechanism of the weld zone microstructure during linear friction welding,which are also the main research topics to study the bonding mechanism of LFW.The microstructures of the welded joints are obtained by stopping the vibration at different time instants during the LFW of dissimilar quality titanium alloy TC17(α+β)/TC17(β),they are observed and analyzed by scanning electron microscope(SEM)and electron back Scatter Diffraction(EBSD).The weld zone dynamic recrystallizations and texture changes during the welding are studied.The results show that when the friction time is only 0.5s,dynamic recrystallization has occurred in the central area of the welding interface and metastableβgrains have been formed.As the friction continues,even after stopping vibration and upsetting,the width of the fine grain zone gradually narrows,the grain orientation distribution becomes more and more concentrated,the proportion of the small-angle grain boundary increases,the proportion of the large-angle grain boundary decreases,and the area of the dynamic recrystallization grain gradually increases.Finally,three textures,{112}<111>,{110}<111>and{123}<111>,are formed in the weld zone,which corresponds to the three BCC slip systems.The main mechanism of this texture formation is friction pressure,instead of friction shear.When the joint is subjected to axial tension,the shear plastic deformation is easily produced in the texture grain,which will reduce the strength of the joint.

关 键 词：线性摩擦焊 钛合金 EBSD 动态再结晶 织构 

分 类 号：V261[航空宇航科学与技术—航空宇航制造工程] TG453[金属学及工艺—焊接]