聚晶金刚石的电火花磨削加工

为探讨在普通电参数下,电火花磨削人造聚晶金刚石(PCD)的加工性能,研究了电极轮转速、开路电压、峰值电流、脉冲宽度以及脉冲间隔对材料去除率、电极损耗以及加工表面粗糙度的影响.结果表明,采用电火花磨削方法,在较小的开路电压和峰值电流下,PCD的加工是可行的.使用电火花磨削方法在材料去除率和表面粗糙度方面要优于普通电火花加工.各个加工参数对加工表面粗糙度的影响不大,而与金刚石颗粒的粒度有关.加工时应选用大的开路电压,而峰值电流不宜取得过大,一般说来,不应超过32 A.脉冲宽度与脉冲间隔之间存在一个最优比例关系,在合理的脉冲宽度与脉冲间隔比例基础上,加大脉冲宽度可以提高加工性能.

The Electrical Discharge Grinding of Polycrystalline Diamond

This paper presented the test of electrical discharge grinding(EDG) of polycrystalline diamond(PCD) with normal electrical discharge machine tool and rotating device.The effects of wheel speed,open-circuit voltage,peak current,pulse duration,and pulse interval of EDG on the material removal rate(MRR),the wheel wear and surface roughness(SR) were investigated respectively.The test result indicates that it is possible to shape PCD blank with this device.The wheel speed of EDG makes MRR increase dramatically.With the EDG,the surface performance is improved.All the parameters investigated have little influence on the SR of PCD.The SR is determined mainly by the grain size of PCD.The higher the open circuit voltage,the larger the MRR is.The effect of peak current on the MRR,WW and SR is similar with the effect of open-circuit voltage.However,the influence of the peak current is much larger than that of the open-circuit voltage.The peak current should be smaller than 32A.There is a best ratio between the pulse on-time and pulse off-time.If the ratio is larger or smaller than that value,there may be an adverse effect on the SR and MRR.Larger pulse on-time increases the MRR and decreases the wheel speed.