摘要
目的获得双态组织Ti17钛合金线性摩擦焊接头合适的焊后热处理(PWHT)工艺,以满足该合金在航空发动机整体叶盘线性摩擦焊工程中的应用要求。方法选用3种热处理温度(600,620,640℃)对接头进行PWHT,利用光镜(OM)及扫描电镜(SEM)观察分析接头微观组织,利用拉伸试验机及显微硬度计测试分析接头力学性能。结果热处理后接头母材(BM)组织与焊态接头相比无明显变化,焊缝区(WZ)及热力影响区(TMAZ)内析出了细小的层片状二次α,使WZ及TMAZ的显微硬度与焊态接头相比均有所提高。随着热处理温度由600℃→620℃→640℃,WZ及TMAZ内二次α相逐渐长大粗化,导致WZ及TMAZ显微硬度随PWHT温度的升高而逐渐降低。结论所选的PWHT温度可改善接头组织,使接头拉伸强度和断后伸长率均高于焊态接头及许用标准。
In order to meet the engineering application requirements of linear friction welded(LFW)Ti17 titanium alloy blisk in aeroengine,the suitable post-welding heat treatment(PWHT)process of LFWed bimodal microstructure Ti17 titanium alloy joint was investigated.Three temperatures(600,620,640℃)were selected to carry out the PWHT.The microstructure of the joints was analyzed in detail by using an optical microscopy and a scanning electron microscopy;the mechanical properties of the joints were tested by means of a tensile testing machine and a microhardness tester.The results reveal that the base metal(BM)microstructure of PWHT joints is similar to that of as-welded joint;fine lamellar secondaryαis formed in weld zone(WZ)and thermo-mechanically affected zone(TMAZ)of PWHT joints,which is contributed to the increase of microhardness compared with the WZ and TMAZ of as-welded joint.With the increase of PWHT temperature(600,620,640℃),lamellar secondaryαin WZ and TMAZ grows and coarsens gradually,resulting in the decrease of microhardness.The PWHT conditions selected in this paper are beneficial to optimize the joint microstructure,which make the tensile strength and elongation of the PWHT joint higher than those of as-welded joint and allowable standard.
作者
郭震国
马铁军
李菊
李文亚
唐龙飞
GUO Zhen-guo;MA Tie-jun;LI Ju;LI Wen-ya;TANG Long-fei(Key Laboratory of Friction Welding Engineering Technology of Shaanxi Province,School of Materials Science and Engineering,Northwestern Polytechnical University,Xi'an 710072,China;Aeronautical Key Laboratory for Welding and Joining Technologies,AVIC Manufacturing Technology Institute,Beijing 100024,China)
出处
《精密成形工程》
北大核心
2021年第5期155-160,共6页
Journal of Netshape Forming Engineering
基金
国家科技重大专项(2017-Ⅶ-0005-0098)。
关键词
线性摩擦焊
Ti17
焊后热处理
微观组织
力学性能
linear friction welding
Ti17 titanium alloy
post-weld heat treatment
microstructure
mechanical property
