暴露温度对5083铝合金搅拌摩擦焊接头力学性能的影响

Effect of Exposure Temperature on Performance of 5083 Aluminum Alloy Friction Stir Welding Joint

研究了在常温、70和170℃下暴露对5083铝合金搅拌摩擦焊接头力学性能的影响.结果表明,常温和70℃暴露对接头的显微硬度、抗拉和屈服强度影响很小,常温和70℃断裂位置为前进侧熔合线处.在170℃下暴露,随着时间的延长,母材和接头的显微硬度值出现大幅降低,100 h时母材最高硬度为81,与常温暴露相比下降了19.在170℃、25 h暴露的试样力学性能最好,抗拉强度达到322 MPa,屈服强度达到291 MPa,但随着170℃下使用时间的延长,接头和母材力学性能逐渐下降,断裂位置为母材.扫描电镜结果显示,断口表面有很多深浅形状不一的韧窝,接头具有较好的塑性,均为韧性断裂.

The effects of exposure at normal temperature,70℃and 170℃on the mechanical properties of the 5083 aluminum alloy friction stir welded(FSW)joint were investigated.The results show that the normal temperature and 70℃exposures have negligible effect on the micro-hardness,tensile strength and yield strength of the joint.Fracture position of normal temperature and 70℃is at the fusion line of the AS side.With an increase in exposure time of 170℃,the micro-hardness value of base metal and joints decreased significantly,the maximum hardness of the base metal at 100 h was 81,compared with the normal temperature decreased by 19;The samples exposed at 170℃for 25 h had the best mechanical properties,tensile strength of 322 MPa and yield strength of 291 MPa.However,with the extension of the exposure time at 170℃,mechanical properties of joint and base metal gradually decreased,and the fracture position was base metal.The scanning results show that there are many dimples with different depth and shapes on the fracture surface.The joint gets good plasticity and is ductile fracture.