MGH956合金TIG焊接接头组织和性能  

Microstructure and mechanical properties of joint of MGH956 alloy in TIG welding

作　　者：雷玉成[1,2] 赵凯[1] 黄巍[1] 梁申勇[1] 郁雯霞[3] 

机构地区：[1]江苏大学材料科学与工程学院,江苏镇江212013 [2]江苏省高端结构材料重点实验室,江苏镇江212013 [3]无锡工艺职业技术学院机电系,江苏无锡214000

出　　处：《江苏大学学报（自然科学版）》2014年第4期479-483,共5页Journal of Jiangsu University：Natural Science Edition

基　　金：国家自然科学基金资助项目(51075191);江苏大学科技创新团队项目(JD0805);江苏省高校博士创新计划项目(CCZZ_0556);江苏高校优势学科建设工程项目(PADD)

摘　　要：分别以自制的高镍焊丝和MGH956合金基体为填充材料,对1.3 mm厚的MGH956合金进行TIG焊接,对比分析两种情况下接头的微观组织及其力学性能.以高镍焊丝作为填充材料进行焊接时,与填加基体相比,焊缝晶粒得到细化,孔洞减少,焊缝中生成了TiC等增强相,保证了焊缝较好的力学性能;同时,基体中的纳米级增强相Al-Y-O复合氧化物团聚倾向降低.力学性能试验表明:填加基体材料的焊缝抗拉强度仅为母材的57%,焊缝出现软化;填加高镍焊丝的焊缝出现硬化,抗拉强度为581 MPa,达到母材强度的80.7%;两种情况下,热影响区硬度与母材相当,接头都表现为脆性断裂.Tungsten insert gas（TIG） weldings of MGH956 alloy plates with 1.3 mm thickness were conducted with base metal（BM） and self-made high Ni wire as fill materials, respectively. The two kinds of joint microstructures and mechanical properties were compared and analyzed. With high Ni wire as fill material in the process of welding, grain refinement is realized in weld joint with reduced holes, and new composite reinforced phase by TiC is produced in the joint to ensure the joint quality and to reduce the agglomerate of nano-scale reinforced Al - Y - O composite oxide particles. The mechanical testing results show that tensile strength of the sample welded by BM welding is only 57% of that of BM with softening at weld metal（WM）. Hardening appears at WM for filling high Ni wire, and the tensile strength of 581 Mpa reaches about 80.7% of that of BM. The two cases of heat affected zone hardness are equal to that of BM, and the fracture surface of two weld joints both exhibit brittle fracture.

关 键 词：MGH956合金 TIG焊接 组织 增强相 力学性能 

分 类 号：TG442[金属学及工艺—焊接]