铝合金搅拌摩擦焊力参量对缺陷的响应规律研究  

Research on the response of force characteristics to defect in aluminum alloy friction stir welding

作　　者：曹鹏 管卫 CAO Peng;GUAN Wei(Jining Port and Shipping Development Center,Jining 272000,Shandong,China;School of Materials and Engineering,Tianjin University,Tianjin 300354,China)

机构地区：[1]济宁市港航事业发展中心,山东济宁272000 [2]天津大学材料科学与工程学院,天津300354

出　　处：《金属加工(热加工)》2025年第3期76-82,共7页MW Metal Forming

基　　金：航空科学基金(20240011048001)。

摘　　要：力参量是搅拌摩擦焊(Friction Stir Welding,FSW)缺陷形成的重要信息载体,在缺陷预测中具有重要作用。利用测力平台实现了铝合金FSW过程中前进阻力、侧向力和轴向压力的原位测量,分析了力参量对缺陷形成及缺陷尺寸的响应规律。结果表明:在典型工艺参数下,焊接过程中三向力呈现出先增加、后稳定、最后快速降低的变化趋势。在低转速(≤750r/min)或高焊接速度(≥240mm/min)条件下,焊缝内部产生隧道缺陷,力参量变化主要体现在轴向压力降低和侧向力增加。侧向力与隧道缺陷尺寸呈正相关,相关系数为0.92;轴向压力与缺陷尺寸呈正相关,相关系数为-0.60。轴向力的降低是由于轴肩对焊缝材料的挤压作用减弱,焊缝材料难以被包裹并迁移至焊缝表面,从而导致隧道和沟槽缺陷产生;侧向力的增加是由于搅拌针驱动材料的能力减弱,导致搅拌针前方材料在焊缝后退侧堆积,加剧了搅拌针对后退侧材料的挤压,进而导致搅拌针后方材料回填困难,形成隧道缺陷。Force components serve as the information carriers for defect evolution in aluminum alloy friction stir welding,playing a crucial role in defect prediction and identification.This paper employs a force measuring platform to conduct in-situ measurements of traverse force,lateral force,and plunge force during the welding process.It further analyzes the relationship between force characteristics and the formation and size of defects.The results indicate that welding force initially increases,then stabilizes,and ultimately decreases rapidly during the welding process.Tunnel defects are observed within the weld under conditions of low rotation speed(≤750r/min)or high welding speed(≥240mm/min).The varitaitons in welding force are primarily characterized by a reduction in plunge force and an increase in lateral force.Notably,the lateral force exhibits a positive correlation with the size of tunnel defects,with a correlation coefficient of 0.92,while the plunge force shows a negative correlation with defect size,with a correlation coefficient of-0.60.Furthermore,the reduction in plunge force is attributed to the diminished extrusion effect of the shoulder on the weld material,making it difficult for the material to be wrapped and migrated to the weld surface,thereby leading to the formation of tunnel and groove defects.The increase in lateral force results from the reduced ability of the stirring pin to drive the material,causing a buildup of material in front of the stirring pin on the retreating side of the weld.This exacerbates the extrusion of materials on the retreating side by the stirring pin,making it challenging for the materials behind the stirring pin to backfill,which ultimately leads to the formation of tunnel defects.

关 键 词：铝合金 搅拌摩擦焊 力参量 缺陷 响应规律 

分 类 号：U45[建筑科学—桥梁与隧道工程]