混粉电火花加工中极性效应的研究

Study on Polarity Effects of Powder-mixed EDM

为研究极性效应对混粉电火花加工的影响规律 ,采用钢对钢加工、铜对钢加工两种电极组合在添加硅粉的煤油工作液及普通煤油工作液中进行实验 ,并更换不同的极性 ,考察了两极材料的去除率和表面粗糙度 ,结果表明负极总能得到更高的材料去除率 ,而正极总能得到更低的表面粗糙度值。此现象可从两极表面能量密度差异的角度予以解释。

In order to understand the influences of polarity effect on powder-mixed electrical discharge machining (EDM), several experiments had been conducted in both kerosene with silicon powder mixed and pure kerosene. For steel workpiece with copper and steel as tool electrode respectively, the material removal rates (MRR) and surface roughness were examined with both the alternative polarities. Experimental results show that higher MRR can be always achieved when workpiece as cathode while lower surface roughness achieved when as anode. The phenomenon can be explained from the viewpoints of differences of energy density between electrodes.