中间层对NiTi/Ti6Al4V激光焊接接头组织性能的影响  

Effect of Interlayer on Microstructure and Mechanical Properties for NiTi/Ti6Al4V Laser Welded Joints

作　　者：崔江梅 陈龙[2] 周志杰 TESHOME Fissha Biruke 柯文超 喻红梅[1] 曾志[2] CUI Jiangmei;CHEN Long;ZHOU Zhijie;TESHOME Fissha Biruke;KE Wenchao;YU Hongmei;ZENG Zhi(Chengdu Technological University,Chengdu 611730,China;University of Electronic Science and Technology of China,Chengdu 611731,China;AVIC International Holding Corporation,Beijing 100101,China)

机构地区：[1]成都工业学院,成都611730 [2]电子科技大学,成都611731 [3]中国航空技术国际控股有限公司,北京100101

出　　处：《航空制造技术》2022年第21期92-97,共6页Aeronautical Manufacturing Technology

基　　金：国家自然科学基金(52175292);四川省科技计划(2021YFG0053)。

摘　　要：为了提升NiTi/Ti6Al4V异种材料激光焊接接头的力学性能,减少脆性金属间化合物的形成,分别通过添加Co、Zr中间层开展NiTi/Ti6Al4V激光焊接。研究了中间层材料对焊接接头微观组织、物相结构与力学性能的影响规律。结果表明,NiTi/Co/Ti6Al4V和NiTi/Zr/Ti6Al4V接头熔合区微观组织均由等轴枝晶、柱状枝晶以及部分宏观偏析区组成,Co与Zr元素分别能取代Ti_(2)Ni脆性金属间化合物中Ni和Ti的位置,从而抑制Ti_(2)Ni脆性相的生成。此外,NiTi/Co/Ti6Al4V和NiTi/Zr/Ti6Al4V接头均在NiTi边界附近出现硬度最大值,分别为543HV和467HV,且均在NiTi边界处发生脆性断裂,其中NiTi/Zr/Ti6Al4V接头有着较大的抗拉强度315.9 MPa和断裂应变1.74%。In order to reduce the formation of brittle intermetallic compounds in NiTi/Ti6Al4V dissimilar laser welding and improve the mechanical properties of welded joints,NiTi/Ti6Al4V laser welding was performed by adding Co and Zr interlayers respectively.The effect of Co/Zr interlayer on microstructure,phase structure and mechanical properties of welded joints was studied.The results show that the microstructure of the fusion zone in NiTi/Co/Ti6Al4V and NiTi/Zr/Ti6Al4V joints is composed of equiaxed dendrites,columnar dendrites and some macroscopic segregation zones.Co and Zr can respectively replace Ni and Ti in Ti_(2)Ni brittle intermetallic compounds,which inhibits the formation of brittle phases.In addition,the maximum hardness of NiTi/Co/Ti6Al4V and NiTi/Zr/Ti6Al4V joints is near the NiTi boundary,543HV and 467HV respectively.Meanwhile,brittle fracture occurs at the NiTi boundary.The NiTi/Zr/Ti6Al4V joint has a large tensile strength of 315.9 MPa and fracture strain of 1.74%.

关 键 词：异种金属 激光焊接 中间层 微观组织 力学性能 

分 类 号：TG456.7[金属学及工艺—焊接]