AZ31B镁合金/不锈钢异种合金双光束激光熔钎焊接特性  

Welding Characteristics of AZ31B Magnesium Alloy/Stainless Steel Dissimilar Alloys by Dual Beam Laser Welding-Brazing Process

作　　者：李俐群[1] 郭伟[1] 檀财旺[1] 

机构地区：[1]哈尔滨工业大学材料科学与工程学院,黑龙江哈尔滨150001

出　　处：《中国激光》2012年第4期60-66,共7页Chinese Journal of Lasers

摘　　要：以镁基焊丝为填充材料,采用双光束激光熔钎焊的方法对AZ31B镁合金/不锈钢的焊接特性进行了研究。分析了不同工艺参数对焊缝成形、接头力学性能和断裂行为的影响。结果表明,采用双光束进行填丝熔钎焊能够获得较满意的外观成形,无明显缺陷,焊接工艺范围较宽。接头拉伸均断裂于熔化焊的镁侧焊缝及热影响区(HAZ),最大剪切强度为193MPa,达到镁合金母材强度的71%。组织分析发现焊缝和HAZ的晶粒粗大,成为接头的薄弱部位,是接头失效的主要原因。钎焊侧界面发生了冶金反应,界面处生成1～2μm的反应层。AZ31B magnesium alloys and 201 stainless steel are joined by laser welding-brazing process with Mg based filler.The welding characteristics including influence of processing parameters on weld appearance,mechanical properties and fracture behavior are studied.Results indicate that satisfactory appearance of welds without evident defects can be achieved by dual beam laser-brazing process with filler.A wide processing window is obtained.The tensile-shear test shows that fracture occurred at two places,weld seam and heat affect zone（HAZ） at the welding side of Mg alloys.The maximum shear strength can reach 193 MPa,which is 71% of that of Mg base metal.The microstructure observed indicates that seam and HAZ are weak parts,which results in failure of joint due to presence of coarse grains.Metallurgical reaction occurs at the brazing side,where reaction layer with thickness of 1~2 μm forms.

关 键 词：激光技术 镁合金 不锈钢 熔钎焊 

分 类 号：TG456.7[金属学及工艺—焊接]