短电弧加工不同直径电极间隙流场研究

Study on Flow Field of Short Arc Processing Gap with Different Diameters

在短电弧加工过程中,利用流体软件Fluent对不同的电极直径加工间隙流场进行仿真,通过极间流场中的压力场与速度场间接得出加工屑排除的变化规律,并通过实验进行验证。结果发现:电极直径的增大可以促进加工屑从加工间隙排出,减少因间隙颗粒的堆积而产生的短路现象,从而避免“二次放电”;当加工深度不变时,电极直径的大小与工件材料的去除率呈正相关,证明短电弧加工过程中存在“面积效应”;电极直径的相对变化对工件表面质量没有明显的改善,即对表面粗糙度的影响不大。

In the process of short arc machining,the fluid software Fluent was used to simulate the gap flow field of different electrode diameters.The rule of chip removal was obtained indirectly through the pressure and velocity fields in the inter-electrode flow field,which was verified by experiments.The results show that the increase of electrode diameter can promote chip discharging from the machining gap and reduce the short circuit phenomenon caused by the accumulation of gap particles,thus avoiding the“secondary discharge”;when the processing depth remains unchanged,the size of electrode diameter is positively correlated with the removal rate of workpiece material,which proves that“area effect”is existed in short arc processing;the relative change of the electrode diameter has no obvious improvement on the surface quality of the workpiece,that is,the influence on the surface roughness is not significant.