搅拌摩擦焊径向阻力的动态测量与分析

利用压力传感器对聚氯乙稀塑料搅拌摩擦焊时搅拌头受到的径向阻力进行动态测量,对引起搅拌头径向阻力变化的原因及相关因素的影响规律进行分析.结果表明,搅拌摩擦焊过程开始后,径向阻力要经过一个先急剧上升,达到峰值后又迅速下降,到某一定值后稳定下来的过程.在其他条件不变的前提下,仅提高搅拌头的旋转速度使径向峰值阻力和稳态阻力都下降,达到峰值和稳态阻力的时间都缩短;仅提高焊接速度使峰值阻力大幅度上升,而稳态阻力却有升有降,但幅度不大,达到峰值阻力的时间变化不大,而达到稳态阻力的时间延长;搅拌头直径的变化会同时引起摩擦发热功率和散热功率的变化,它对径向阻力的影响比较复杂.

DYNAMIC MEASURING AND ANALYSIS ON RADIAL RESISTANT FORCE IN FRICTION STIR WELDING

Radial resistant force against the moving tool was measured dynamically and influences of some factors on the force were analyzed.It shows that the force rises up sharply at the beginning of friction stir welding As soon as reaching the top it decreases down rapidly,and then goes to a value at which the welding procedure is steady.If increasing the rotation speed of tool,but keeping all other parameters and factors fLxed,the top force and the steady force are both decreased,and the times taken for reaching the top force and steady force are shortened. If increasing welding speed only,the top force goes up greatly, and the steady force increases or decreases in a rather small range,and the time taken for the top force changes a little,but the time for the steady force is prolonged;The influences of the diameter of pin on the force are complex,because the change of the diameter of pin leads to the variation of frictional heating power and the cooling power simultaneously.