7050铝合金搅拌摩擦焊动态再结晶组织影响因素

进行了不同旋转频率和焊接速度下的7050铝合金搅拌摩擦焊试验，研究了搅拌头旋转频率和焊接速度对焊核区晶粒尺寸的影响．为进一步分析焊接参数影响焊核区晶粒尺寸的机理，进行了不同应变速率和变形温度下的等温压缩试验．分析了变形参数对动态再结晶的影响规律．结果表明，焊核区晶粒尺寸随搅拌头旋转频率的变化不大，随焊接速度的增加而减小．在发生完全动态再结晶的范围之内，再结晶晶粒尺寸随着lnZ值的增大而减小．焊接参数对z参数具有不同的影响规律，进而影响焊核区晶粒尺寸．

Influence factors of dynamic recrystallization of 7050 aluminium alloy friction stir weld

Friction stir welding of 7050 aluminum alloy under different rotation rates and tool traverse speeds was conducted and the influence of welding parameters on the grain size of nugget zone was investigated.To analyze the affecting mechanism of welding parameters on the grain size of nugget zone,isothermal compression experiments under different strain rates and deformation temperatures were performed and the influence of deformation parameters on the dynamic recrystallization was analyzed.Results showed that grain size in nugget zone changed slightly with the increase of the rotation rate,while it decreased with the increase of tool traverse speed.Within the range of complete dynamic recrystallization,the recrystallization grain size decreased with increase of the value of lnZ.The welding parameters affected the Zenner-Hollomon parameter and then determined the grain size in nugget zone.