2195铝锂合金填充式摩擦点焊接头显微组织与力学性能

Microstructure and Mechanical Properties of Refil Friction Spot Welds in 2195Al-Li Alloy

研究了2195铝锂合金填充式摩擦点焊不同焊接时间对接头力学性能的影响，对典型接头微观组织进行了分析和横截面显微硬度测试．实验结果表明，预热时间在0．2～1．4s时，焊点剪切拉伸抗力与十字托伸抗力均先增大后减小；焊接时间在1．8—3．2s之间时，焊点剪切拉伸抗力与十字拉伸抗力均增大；摩擦点焊接头可分为焊核区、竖直面热机影响区、水平面热机影响区三个典型区域，其中竖直面热机影响区与焊核区的连接界面为接头的薄弱环节；焊核区发生了较大程度的软化．

2195 aluminium-lithium alloy was welded with refill friction spot welding process. The influence of welding time on the mechanical properties was studied, microstructure and microhardness of the typical joint were tested. The results show that the shear strength and cross strength of the joint were increased first and then decreased with the worm-up time from 0.2s to 1.4s. Both shear strength and cross strength were increased with the welding time from 1.8s to 3.2s. The joint cross section can be divided into weld nugget zone （ NZ）, vertical thermomechanical affected zone （vTMAZ） and horizontal thermomechanical affected zone （hTMAZ）. The interface between the NZ and vTMAZ is the weak joining area. The microhardness in the NZ decreases obviously.