摘要
采用搅拌摩擦焊对2 mm厚6061-T6铝合金板材进行连接,研究焊后时效、固溶处理、固溶时效工艺对接头的显微组织及力学性能的影响。结果表明：焊后接头焊核区发生了动态再结晶,形成了细小的等轴晶;热机影响区晶粒发生明显的塑性变形而呈拉长形状。焊态及焊后时效处理的接头硬度分布大致相同,焊缝中心两侧约12 mm范围内的硬度明显低于母材。经过固溶及固溶时效后,接头焊核区硬度显著升高,焊态接头软化现象基本消除。经焊后固溶时效后,β″-Mg2Si强化相析出,接头的抗拉强度、伸长率显著增大,拉伸断口存在大量细小的韧窝,呈韧性断裂状态。
6061-T6 plates with thickness of 2 mm were welded by using friction stir welding（FSW） and the effects of postweld aging, solid solution and solution aging on the microstructure and mechanical properties of the welded joint were investigated. The results show that dynamic recrystallization occurs in the nugget zone（NZ） of the joint after welding,resulting in the formation of small equiaxed grains, and the grains in thermal-mechanically affected zone（TMAZ） have obvious plastic deformation and show elongated shape. The hardness distribution of the joint in weld state and postweld aging state is approximately the same, the hardness of about 12 mm region at both sides of the weld center is significantly lower than that of base metal. After solid solution and solution aging, the hardness of NZ of the joint increases obviously, and the softening of the welded joint is basically eliminated. After solution aging, β″-Mg2 Si strengthening phase precipitates, and the tensile strength, elongation of the joint increase greatly, and there is a large number of small dimples in the tensile fracture,which shows ductile fracture.
作者
袁豪峰
杨峰
陈亮
石端虎
何敏
YUAN Haofeng;YANG Feng;CHEN Liang;SHI Duanhu;HE Min(School of Mechanical＆Electrical Engineering, Xuzhou Institute of Technology, Xuzhou 221018, China;Jiangsu Key Laboratory of Large Engineering Equipment Detection and Control, Xuzhou 221018, China)
出处
《热加工工艺》
CSCD
北大核心
2018年第11期59-62,70,共5页
Hot Working Technology
基金
江苏省大学生创新创业项目(XCX2017027)
