送丝速度对Ti-3Al-6Mo-2Fe-2Zr钛合金激光填丝焊接头组织与性能的影响  

Effect of wire feed rate on microstructure and properties of laser welded Ti-3Al-6Mo-2Fe-2Zr joints with filler wire

作　　者：张可召 蔡嘉梦 刘栋 陈锦伊 包晔峰[1] 牛红志[2] ZHANG Kezhao;CAI Jiameng;LIU Dong;CHEN Jinyi;BAO Yefeng;NIU Hongzhi(Hohai University,Changzhou,213022,China;Northeastern University,Shenyang,110819,China)

机构地区：[1]河海大学,常州213022 [2]东北大学,沈阳110819

出　　处：《焊接学报》2022年第12期35-40,I0005,共7页Transactions of The China Welding Institution

基　　金：国家自然科学基金资助项目(51804097);中央高校基本科研业务费专项资金资助项目(B220202026);常州市科技计划资助(CJ20220074).

摘　　要：采用Ti-6Al-4V(TC4)焊丝对2 mm厚的Ti-3Al-6Mo-2Fe-2Zr钛合金进行激光填丝焊接,利用光学显微镜、扫描电子显微镜、X射线能谱仪等分析测试方法研究了送丝速度对接头显微组织和力学性能的影响.结果表明,由于从熔合线至母材受到焊接热作用逐渐递减,热影响区组织依次为单一β相、基体β相+初生αp相、基体β相+初生αp相+少量次生αs相.焊缝中有针状α'相生成,且分布不均匀.随着送丝速度的增加,针状α'相的数量增加,尺寸增大.激光填丝焊接头的抗拉强度及断后伸长率均低于母材,随送丝速度的增加,接头抗拉强度上升,断后伸长率下降.其原因在于TC4焊丝的加入,促使针状α'相在焊缝中析出,送丝速度加快,造成焊缝中钼当量[Mo]eq降低,析出的针状α'相数量进一步增多,尺寸增大.针状α'相的析出提高了焊缝强度,当送丝速度大于1.0 m/min时,接头的断裂位置为热影响区.The Ti-6Al-4V(TC4)filler wire was used to join 2 mm thick Ti-3Al-6Mo-2Fe-2Zr titanium alloy during laser welding process.Investigations concerning the influence of wire feeding rate on microstructure and tensile properties were conducted on laser welded Ti-3Al-6Mo-2Fe-2Zr joints with filler wire by optical microscope,scanning electron microscope,and X ray energy spectrometer and other analytical testing methods.The results show that,due to the decreasing heat effect from fusion line to base metal,the microstructure of the heat affected zone is divided as follows:singleβregion,primaryα+matrixβregion,and primaryα+retained secondaryα+matrixβregion.Acicularα'phase is formed in the fusion zone,and the distribution is not uniform.As the wire feed speed increases,the number and size of acicularα'phase increases.The tensile strength and elongation of laser welded joints with filler wire are lower than those of the base metal.With the increase of wire feeding rate,the tensile strength of the joint increases and the elongation decreases.The reason is attributed to that,as the wire feeding rate increased,the[Mo]eq in the fusion zone decreased correspondingly,which led to the increment in the number and size ofα'phase.When the wire feeding rate was higher than 1.0 m/min,the fracture location changed from fusion zone to heat affected zone because of the strengthening effects ofα'phase.

关 键 词：激光填丝焊 Β钛合金 微观组织 拉伸性能 

分 类 号：TG454[金属学及工艺—焊接]