【摘要】 以外加间歇交变纵向磁场MIG焊接铝合金为研究对象,采用高速摄像技术拍摄熔滴形成、长大及脱离的过程,观测并分析外加纵向磁场和不加纵向磁场时熔滴过渡的特点.结果表明,外加间歇交变纵向磁场的熔滴在过渡过程中发生了明显变化,其形态由不加磁场时的球形变为扁长的椭球形,偏离焊丝轴线下落,并且熔滴自身发生旋转.在磁场频率相同的情况下,激磁电流较小时熔滴过渡所需时间在4.5~6 ms范围,激磁电流较大时熔滴过渡所需时间在5~15 ms范围内,可知激磁电流对熔滴过渡影响较大.更多还原

【Abstract】 When aluminum alloy was welded by metal inert-gas(MIG) welding with longitudinal intermittent alternative magnetic fields,a highspeed video camera was used to view the whole process of electrode melting,a droplet developing at the electrode end,the droplet detaching and transferring to the weld pool.And the difference between droplet transition with longitudinal magnetic and without longitudinal magnetic was analyzed.The experiment results indicate that there are obvious change in the metal transfer with longitudinal intermittent alternative magnetic fields,which the shape of droplet changes from globular without longitudinal magnetic to flat shape,and the droplets detach from the tip of the wire,diverge from the axial line of the wire and fall down with turning movement.With the same frequencies,droplet transition time ranges from 4.5 ms to 6 ms when excitatory current is smaller,but droplet transition time needed ranges from 5 ms to 15 ms when excitatory current is larger,so excitatory current has a large influence on droplet transfer.更多还原