铝合金静止轴肩搅拌摩擦焊组织非均质性对接头力学性能的影响

发布时间：2018-05-04 00:12

本文选题：-T铝合金 + 静止轴肩搅拌摩擦焊　；参考：《焊接学报》2017年08期

【摘要】：对6061-T6铝合金静止轴肩搅拌摩擦焊(stationary shoulder friction stir welded,SSFSW)接头组织非均质性与力学性能的相互影响进行了定量分析.结果表明,SSFSW焊接接头存在明显的组织非均质性,表现在晶粒尺寸及形状、沉淀相种类及分布形态不同,其中沉淀相析出不同是影响力学性能差异的主要因素.由于组织非均质性导致紧邻焊核区的热影响区软化严重,其硬度和抗拉强度在接头区域最低,分别为母材的60%和72%,为接头最薄弱部分.由于沉淀强化和晶粒细化效应,焊核区的强度与塑性最好,而抗拉强度和断后伸长率分别达到母材的88%和215%.随着与焊核区距离的增加,热影响区抗拉强度和屈服强度逐渐增加,断后伸长率不断降低.
[Abstract]:The interaction between microstructure heterogeneity and mechanical properties of stationary shoulder friction stir welded SSFSWs welded by static shaft-shoulder friction stir welding (FSW) of 6061-T6 aluminum alloy was quantitatively analyzed. The results show that there is obvious microstructure heterogeneity in SSFSW welded joints, which is characterized by different grain size and shape, type and distribution of precipitated phases, among which the precipitation of precipitated phases is the main factor affecting the difference of mechanical properties. The hardness and tensile strength of the heat-affected zone adjacent to the nuke zone are the lowest in the joint area, which are 60% and 72% of the base metal, respectively, and the weakest part of the joint. Due to the effect of precipitation strengthening and grain refinement, the strength and plasticity of the nugget are the best, while the tensile strength and the elongation after breaking reach 88% and 215% of the base metal, respectively. The tensile strength and yield strength of the heat-affected zone increase gradually with the increase of the distance from the nugget zone, and the elongation of the heat-affected zone decreases continuously after breaking.
【作者单位】：天津大学天津市现代连接技术重点实验室;北京卫星制造厂;
【基金】：五院CAST创新基金资助项目(C02016056)
【分类号】：TG457.14

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