摘要
以0.02mm厚的铜箔作为标示材料、1mm和2mm厚的2024铝合金薄板作为基材,采用不同的叠加方式组成叠层并进行搅拌摩擦焊接(Friction stir welding,FSW)试验,分析搅拌针端部挤压区塑性金属的流动行为及其对焊缝成形的影响。结果表明,在FSW焊接过程中,焊缝上部被塑化的金属不断地沿着搅拌针螺纹旋向往搅拌针端部迁移、长大,形成挤压区。此挤压区由位于搅拌针两侧的扩展区和位于搅拌针端面下方的变形区组成。其中,变形区的金属一部分来自从焊缝上部迁移而来的塑性金属;另一部分来自搅拌针端面下方母材经旋转摩擦作用而发生塑性变形的金属。挤压区塑性金属的流动方式分为轴向挤压迁移、水平摩擦迁移和绕流迁移三种。对厚板进行FSW焊接时,挤压区的塑性金属倾向以绕流迁移方式为主,导致焊缝内部形成疏松区或孔洞型缺陷。
For the sake of analyzing the flow behavior of plastic metal in extruded zone around tool pin-tip and its effect on formation quality of the weld,friction stir welding(FSW)experiments were carried out,taking thick copper foils with thickness of 0.02 mm as insert tracer material and 2024 aluminum alloy sheets with thickness of 1 mm and 2 mm as base metal,adopting different stacking methods.It could be found during FSW process that the plasticized metal on upper part of the weld continuously migrated towards the tool pin-tip along the pin thread groove direction,grew up and form an extruded zone around the pin-tip.The extruded zone generally consisted of an expanded zone located on both sides of the pin and a deformed zone under the pin-tip surface.Moreover,the metals in the deformed zone included two parts,one came from the plasticized metal migrated from the weld top,and the other came from the deformed metal of original base material suffered from the rotation frictional force.The flow patterns of plastic metals in the extruded zone were divided into three types:axial-extruding flow,horizontal-friction flow and bypassing flow.For FSW of thick plate,the plastic metals in the extruded zone tended to transfer around the pin in the bypassing flow way,which leaded to the formation of loose zone or cavity defect inside the weld.
作者
毛育青
柯黎明
江周明
MAO Yuqing;KE Liming;JIANG Zhouming(Key Laboratory of Nondestructive Testing,Ministry of Education,Nanchang Hangkong University,Nanchang 330063;National Defence Key Discipline Laboratory of Light Alloy Processing Science and Technology, Nanchang Hangkong University,Nanchang 330063)
出处
《材料导报》
EI
CAS
CSCD
北大核心
2018年第20期3612-3617,共6页
Materials Reports
基金
无损检测技术教育部重点实验室开放基金(EW201703508)
江西省教育厅科技项目(DA201803145)
轻合金加工科学与技术国防重点学科实验开放基金(EG201703503)
南昌航空大学博士科研启动基金(EA201803212)
