S线缺陷对搅拌摩擦焊接头断裂机制的影响  

Influence of S Curve Defect on Fracture Mechanism of Friction Stir Welding Joints

作　　者：高双胜[1] 易冠英 赵宸[2] 国旭明[1] 

机构地区：[1]沈阳航空航天大学材料科学与工程学院,辽宁沈阳110136 [2]沈阳市第二十中学,辽宁沈阳110002

出　　处：《热加工工艺》2016年第7期198-199,206,共3页Hot Working Technology

基　　金：国家自然科学基金项目(51204111);航空科学基金项目(2014ZE54021);辽宁省自然科学基金项目(2014024009)

摘　　要：采用搅拌摩擦焊接技术对9 mm厚的7N01铝合金进行对接焊接,焊后对接头进行拉伸试验,并通过声发射设备进行监测。根据接头的力学性能、声发射信号特征、断口形貌及金相组织等,分析S线缺陷对接头断裂机制的影响。结果表明:S线缺陷降低了接头的屈服强度和抗拉强度,在拉伸过程中,S线的扩展会导致持续时间的声发射信号明显增大。存在S线缺陷的接头拉伸断口平滑,塑性变形能力变差。7N01 Al alloy with 9 mm thickness was friction stir welded.Tensile test was carried out after welding of the joint, and the joint was monitored through the acoustic emission equipment; combined with the mechanical properties of joint, acoustic emission signal characteristics, and fracture scanning microstructure etc, the effect of S curve defects on joint fracture mechanism was analysed. Studies show that, S curve defects reduce the yield strength and tensile strength of the joint; in the process of drawing, the crack extension of S curve defects increases the acoustic emission signal of short duration; by fracture scanning, the plastic deformation of the joint with S curve and smooth fracture around the defect are lower than those with no defect.

关 键 词：搅拌摩擦焊接 S线缺陷 声发射 断裂 

分 类 号：TG453.9[金属学及工艺—焊接]