铝合金超声辅助搅拌摩擦焊接接头组织性能研究  

Microstructure and Properties of Aluminium Alloy Welding Joint by Ultrasonic-assisted Friction Stir Welding

作　　者：陈超[1] 余朗 陈玉华[1] 陈伟[1] 张体明 CHEN Chao;YU Lang;CHEN Yu-hua;CHEN Wei;ZHANG Ti-ming(Department of Welding Engineering,Nanchang Hangkong University,Nanchang 330036,China)

机构地区：[1]南昌航空大学焊接工程系,南昌330036

出　　处：《精密成形工程》2018年第5期33-37,共5页Journal of Netshape Forming Engineering

基　　金：国家自然科学基金(51265042);江西省优势科技创新团队建设专项计划(20171BCB24007);江西省青年科学家培养计划(20153BCB23038);航空科学基金(2017ZE56010)

摘　　要：目的探究超声振动对铝合金搅拌摩擦焊的作用效果。方法分别采用普通搅拌摩擦焊和超声辅助搅拌摩擦焊方法,对7075铝合金进行焊接试验,并对焊接接头的微观组织、力学性能、断口形貌进行分析。结果普通搅拌摩擦焊焊缝中生成了隧道型缺陷,施加超声振动后,缺陷消失,形成了无缺陷的良好接头,且与普通搅拌摩擦焊相比,超声辅助搅拌摩擦焊焊缝热影响区晶粒长大程度较小,焊核晶粒细化。接头强度明显提高,达到铝合金母材强度的71.5%,接头断裂模式为韧窝和准解理的混合断裂形式。结论超声振动促进了塑性金属的流动,能有效抑制孔洞、隧道型缺陷等的形成,同时超声振动能在提升金属塑性的同时,降低焊缝的热输入。The paper aims to explore effects of ultrasonic vibration on friction stir welding of aluminum alloy.Microstructure,mechanical property and fracture surface of 7075-T6 aluminum alloy were analyzed through ordinary friction stir welding and ultrasonic-assisted friction stir welding respectively.A tunnel-type defect was generated in the ordinary friction stir welding.After the ultrasonic vibration was applied,the defect disappeared and a good joint without defect was formed.Compared with the ordinary friction stir welding,the degree of growth of heat affected zone grains welded by ultrasonic-assisted friction stir welding was small,the grain size of the weld nugget was refined,the joint strength was obviously improved,and it reached 71.5%of the strength of the aluminum alloy base metal.The joint fracture mode was a mixed fracture mode of dimple and quasi-cleavage.Ultrasonic vibration promotes the flow of plastic metal,which can effectively inhibit the formation of holes,tunnel-type defects,etc.At the same time,ultrasonic vibration can increase the plasticity of the metal and reduce the heat input of the weld.

关 键 词：超声辅助搅拌摩擦焊 组织 性能 

分 类 号：TG453.9[金属学及工艺—焊接]