钛基复合材料TIG焊接接头的显微组织和拉伸性能  

Microstructure and Tensile Properties of Titanium Matrix Composite TIG Welded Joint

作　　者：潘玉维 毛建伟[2] 张立新[1] PAN Yuwei;MAO Jianwei;ZHANG Lixin(Tangshan Iron&Steel Group Co.,Ltd.,Tangshan 063016,China;State Key Laboratory of Metal Matrix Composites,Shanghai Jiaotong University,Shanghai 200240,China)

机构地区：[1]唐山钢铁集团有限责任公司,唐山063016 [2]上海交通大学,金属基复合材料国家重点实验室,上海200240

出　　处：《机械工程材料》2020年第5期1-5,53,共6页Materials For Mechanical Engineering

基　　金：国家自然科学基金资助项目(U1602274,51875349,51741108);中国航空科学基金资助项目(20173625005)。

摘　　要：采用非熔化极惰性气体钨极保护(TIG)焊技术对非连续增强钛基复合材料进行焊接,研究了焊接接头的显微组织与拉伸性能。结果表明:TIG焊接可较好地实现钛基复合材料的连接,焊缝成形良好,表面均匀洁净,未见微裂纹、气孔等焊接缺陷;接头由焊缝区、热影响区和母材区组成;接头中焊缝区和靠近焊缝的热影响区中β相晶界上分布的增强体TiB具有较高的长径比,细化程度较高,同时焊缝区和靠近焊缝的热影响区中存在大量针状马氏体α′相;接头的抗拉强度为1 137MPa,为母材的92%,断后伸长率为2.20%;接头拉伸时均在母材区断裂,拉伸断口主要呈韧性断裂特征,部分区域呈沿晶断裂特征。Discontinuously reinforced titanium matrix composite was welded by tungsten inert gas welding(TIG)technique.The microstructure and tensile properties of the welded joint were studied.The results show that TIG welding can well realize the connection of titanium matrix composite.The weld had the good formation with an even and clean surface,and no welding defects such as microcracks and pores were found.The joint consisted of weld zone,heat-affected zone and base metal zone.The TiB reinforcements distributed on the boundaries of β phase in the weld zone and the heat affected zone near the weld in the joint had high aspect ratios with a high degree of refinement,and there were a large number of acicular matensiteα′phase in the two regions.The tensile strength of the joint was 1 137 MPa,92% of that of the base metal,and the percentage elongation after fracture was 2.20%.The joint fractured at the base metal zone during tensile;the tensile fracture of the joint was mainly characterized by ductile fracture,and local areas showed intergranular fracture features.

关 键 词：非熔化极惰性气体钨极保护焊 钛基复合材料 增强体 显微组织 拉伸性能 

分 类 号：TG442[金属学及工艺—焊接]