2Al2铝合金点焊微裂纹高温愈合行为的研究  

Research on High Temperature Healing Behavior of 2Al2 Aluminum Alloy Spot Welding Tiny Crack

作　　者：朱晓东[1] 张勇[1] 周昀芸 谢红霞[1] 王博[1] 胡喆[1] 

机构地区：[1]西北工业大学凝固技术国家重点实验室摩擦焊接陕西省重点实验室,西安710072

出　　处：《焊管》2015年第9期1-5,共5页Welded Pipe and Tube

基　　金：国家自然科学基金资助项目(项目号51275418);陕西省重点科技创新团队项目(项目号2014KCT-12);陕西省科技统筹创新工程计划项目(项目号2012HBSZS02)

摘　　要：选用2Al2高强铝合金,采用三相次级整流电阻点焊机和特定的焊接参数预制内裂纹,然后在2Al2铝合金固溶温度(500℃)下对接头内裂纹进行6 h的高温愈合处理。采用金相显微镜、扫描电镜和室温力学性能测试等手段分析接头的微观组织形貌、裂纹形态及断口形貌,研究接头中裂纹的高温愈合行为及愈合行为对接头力学性能的影响。结果表明,在高温热量作用下,接头微观组织整体均匀化,裂纹产生局部愈合,接头塑性有所改善,接头断裂方式由解理断裂转变为准解理断裂。但经过高温愈合处理后,接头显微硬度和剪切性能均有所下降。In this article, it adopted three-phase secondary rectification resistance spot welding machine and specific welding parameters to prefabricate inner cracks in 2A12 high-strength aluminum alloy, then the inner cracks in welded joints of 2A12 were carried out high temperature healing treatment at solution temperature（500 ℃） for 6 hours. The microstructure, crack morphology, and fracture morphology of welded joints were analyzed by metalloscope, SEM and room temperature mechanical property test, and the high temperature healing behavior and its influence on welded joint mechanical properties were studied. The results indicated that under the effect of high temperature, the microstructure of welded joint homogenized, the partial cracks are healed, the plasticity of welded joints is improved, and the fracture mode of welded joint changes from cleavage fracture to quasi cleavage fracture. But the microhardness and shear property significantly reduce after high temperature healing treatment.

关 键 词：焊接 电阻点焊 2Al2铝合金 裂纹愈合 高温处理 力学性能 

分 类 号：TG44[金属学及工艺—焊接]