中国中车南京浦镇车辆车辆有限公司火巧英等人近日发表论文，以6 mm厚6005A-T6铝合金列车地板型材为研究对象，系统探究搅拌摩擦焊（FSW）过程中搅拌头横向偏移对焊缝成形及接头性能的影响，并确定其偏移容限。通过设计横向偏移（不超过搅拌针直径的1/3，即3 mm）试验，对比分析了搅拌头偏向搭接侧与支撑侧时的接头宏观/微观组织、硬度、拉伸性能、残余应力及疲劳性能。结果表明：偏移方向改变顶锻力分布及接头变形模式，偏向支撑侧有利于减小搭接间隙；接头显微硬度呈“W”形分布，热影响区硬度最低为力学薄弱区；偏移量在容限内时，接头抗拉强度达211~222 MPa（超过母材强度80%），断裂位置均位于搭接侧热影响区，断口呈现典型韧性断裂特征；横向残余应力呈中间高、两端低分布，最大值约169~171 MPa；疲劳极限为112 MPa（50%存活率）。综合认为，当横向偏移量控制在搅拌针直径1/3以内时，可保证有效熔深、控制变形并避免隧道或孔洞缺陷，建议在实际焊接中优先使搅拌头偏向型材腹板支撑侧布置。
Abstract
This study systematically investigates the effect of tool lateral offset on weld formation and joint performance during friction stir welding (FSW) of 6 mm thick 6005A-T6 aluminum alloy train floor extrusions, and determines the offset tolerance. Through lateral offset tests (within 1/3 of the pin radius, i.e., 3 mm), a comparative analysis was conducted on the macro/microstructure, hardness, tensile properties, residual stress, and fatigue performance of joints when the tool was offset toward the lap side and the support side. The results show that the offset direction significantly affects the distribution of forging force and joint deformation; offset toward the support side helps reduce the lap gap. The microhardness distribution of the joint exhibits a “W” shape, with the heat-affected zone (HAZ) being the mechanically weak region. When the offset is within the tolerance, the joint tensile strength reaches 211-222 MPa (exceeding 80% of the base metal strength), and fracture occurs in the HAZ on the lap side, with the fracture surface showing typical ductile fracture characteristics. The transverse residual stress distribution is high in the middle and low at both ends, with a maximum value of approximately 169-171 MPa. The fatigue limit is 112 MPa (at 50% survival rate). It is concluded that when the lateral offset is controlled within 1/3 of the pin radius, effective penetration depth can be ensured, deformation controlled, and tunnel or void defects avoided. In practical welding, it is recommended to preferentially position the tool toward the support side of the profile web.
阅读原文：http://www.fsw.net.cn/fsw/zb_users/upload/2026/9/20260921213622582258.pdf