采用AlSi5焊丝CMT熔钎焊7075铝合金/镀锌钢板接头组织及性能分析  

Microstructure and mechanical property of CMT fusionbrazed joint with AlSi5 filler wire between 7075 aluminum alloy and galvanized steel sheets

作　　者：秦优琼[1] 焦国力 

机构地区：[1]上海工程技术大学材料工程学院,上海201620

出　　处：《焊接学报》2017年第9期119-123,共5页Transactions of The China Welding Institution

基　　金：上海工程技术大学研究生科研创新计划资助项目(16KY0516);上海汽车工业科技发展基金项目(1404)

摘　　要：采用CMT熔钎焊,对车用镀锌钢板和7075铝合金进行焊接试验.通过光学显微镜、扫描电镜(SEM)、EDS能谱分析和X射线衍射仪对接头的显微组织及断口形貌进行分析.结果表明,焊缝成形美观,焊接时铝侧发生熔化焊,钢侧发生钎焊.焊接接头分为富锌区、焊缝区、焊缝热影响区和钢侧界面层,其中钢侧界面层主要生成Fe Al3和Fe2Al5.同时对熔钎焊接头进行拉剪试验,发现接头的断裂部分发生在钢侧界面层为解离断裂,属于脆性断裂,发生在热影响区的为韧窝断裂,属于韧性断裂,接头承受的最大拉剪强度为127 MPa.Fusion-brazing of 7075 aluminum alloy and galvanized steel is conducted with cold metal transfer method.The microstructure and fracture of the joint are analyzed by optical microscope,SEM,EDS and XRD. The results show that the aluminum alloy is fusion welded and the galvanized steel is brazed. The microstructure of the joint can be divided into zincrich zone,weld metal zone,heat-affected zone and intermetallic compounds layer. The intermetallic compounds layer is composed of FeAl_3 and Fe_2Al_5. Meanwhile,the tensile-shear test is carried out. When fracture occurs in intermetallic compounds layer,it belongs to cleavage fracture. When fracture occurs in the heatedaffected zone,it is dimple fracture. The maximum tensile-shear strength of the joint is 127 MPa.

关 键 词：冷金属过渡熔钎焊 微观组织 力学性能 7075铝合金 镀锌钢板 

分 类 号：TG454[金属学及工艺—焊接]