摘要
以厚度50μm的纯铜箔作中间层,利用交流TIG熔钎焊方法对AZ31B镁合金和TC4钛合金进行搭接焊,观察分析了焊接接头的宏观形貌及显微组织,测定了焊接接头的元素分布及抗拉强度。结果表明,在电流70 A、焊接速度120 mm/min的条件下可以实现镁钛异种金属的可靠连接,熔钎焊接头由焊缝区、镁合金母材的热影响区和镁/钛界面结合区三部分组成,其中镁/钛界面结合区呈锯齿状嵌入式结构,其显微组织由α-Ti、α-Mg及沿α-Mg晶界分布的Mg-Cu-Al共晶体组成;试样拉伸断裂发生在焊缝区与热影响区的交接处,抗拉强度达到140 MPa,锯齿状嵌入式结构提高了镁/钛界面结合强度。
The lap welding of AZ31 B and TC4 was carried out by using alternating current TIG welding-brazing with 50μm pure copper foil as interlayer. The macroscopic morphology and microstructure of the welding-brazing joint were observed and analyzed, and the elements distribution and the tensile strength of the joint were tested. The results shows that reliable connection of Mg/Ti dissimilar metals can be realized under the condition of 70 A and welding speed of 120 mm/min. The joint consists of weld zone, heat affected zone of AZ31 B and Mg/Ti bonding area. The bonding area is jagged and embedded structure, and the microstructure consists of α-Ti, α-Mg and a small amount of Mg-Cu-Al eutectic distributed along α-Mg grain boundary. The tensile fracture of the welding-brazing joint occurs at the junction of the weld zone and the heat affected zone, and the tensile strength reaches 140 MPa. The jagged the embedded structure improves the Mg/Ti bonding strength.
作者
刘晓庆
杜双明
孔令明
LIU Xiaoqing;DU Shuangming;KONG Lingming(College of Materials Science and Engineering, Xi＇an University of Science and Technology, Xi＇an 710054, China)
出处
《热加工工艺》
CSCD
北大核心
2018年第7期209-211,214,共4页
Hot Working Technology
