(南昌航空大学 轻合金加工科学与技术国防重点学科实验室，南昌 330063)
摘 要: 研究搅拌针表面螺纹头数与轴肩下压量对8 mm厚的LY12铝合金板材在搅拌摩擦焊过程中焊缝塑性金属在搅拌针轴向的迁移量的影响。结果表明：螺纹内的塑性金属因受到螺纹表面挤压力和螺纹表面与金属间摩擦力的共同驱动而在搅拌针轴向产生迁移，单位时间内塑性金属的轴向迁移量取决于引起金属迁移的驱动力大小和单位长度螺纹内携带金属的量。增加搅拌针表面螺纹头数和增大焊缝所受轴向的挤压力均能使焊缝塑性金属的轴向迁移量增加，其宏观表现为呈“洋葱瓣”花纹状的焊核横截面积增大。
关键字: 搅拌摩擦焊；迁移量；“洋葱瓣”花纹；焊核横截面积
transfer of metal in weld thickness direction
（National Defense Key Disciplines Laboratory of Light Alloy Processing Science and Technology,
Nanchang Hangkong University, Nanchang 330063, China）
Abstract:The effects of thread number of the stirring pin and pluge depth on the plastic metal transfer volume in weld thickness direction of 8 mm Al alloy LY12 during friction stir welding process were studied. The results show that the pressure from the surface of the thread to plastic metal and the friction force between the plastic metal and the surface of the thread are the main reason for driving plastic metal to transfer in the weld thickness direction; the plastic metal transfer volume in the unit time depends on the driving force of metal transfer and the amount of metal in unit length of thread. The plastic metal transfer volume in the weld thickness direction increases with increasing thread number of the stirring pin and the pressure in the weld thickness direction. The macro structure shows the increase of the transverse section area of the weld nugget with the onion shape.
Key words: friction stir welding; transfer volume; onion ring; area of nugget transverse section
