ABSTRACT

Discharge channel motion characteristics are one of the focuses of electrical discharge machining (EDM) mechanism research. Based on single pulse discharge experiments, discharge channel motion laws of wire-cut EDM (WEDM) under different electrical parameters were researched. Results show that discharge channel motion speeds are highest at the beginning of the discharge, then drop sharply, and finally enter a relatively stable state, due to the current density change, pressure difference change between the inside and outside of the discharge channel, and the electrode wire shape itself. When discharge time lasts from 0.5 μs to 5 μs, the discharge channel average moving speed drops by about 60%, and when discharge time lasts about 15–25 μs, the discharge channel diameter expands to the maximum. Continuous machining experiment reveals that the variation laws of both cutting efficiency and a single discharge crater surface area with electrical parameters are consistent, that is, the motion laws of a single pulse discharge channel can microcosmically reveal cutting efficiency variation laws in WEDM macroscopically. Improving cutting efficiency only by increasing pulse energy (especially pulse width) is difficult. In high-speed WEDM (HSWEDM) process, the pulse width exceeding 75 μs is proved to have little effect on cutting efficiency improvement.

摘要

放电通道运动特性是放电加工（EDM）机理研究的重点之一。在单脉冲放电实验的基础上，研究了电火花线切割机（WEDM）在不同电参数下的放电通道运动规律。结果表明，由于电流密度的变化，放电通道内外压力差的变化以及放电通道的运动，放电通道的运动速度在放电开始时最高，然后急剧下降，最终进入相对稳定的状态。电极线本身形状。当放电时间从0.5μs持续到5μs时，排放通道的平均移动速度下降约60％，而当放电时间持续约15–25μs时，排放通道的直径最大。连续加工实验表明，切削效率的变化规律与单个带电参数的弧坑表面积的变化规律是一致的，也就是说，单个脉冲放电通道的运动规律可以从微观上微观地揭示WEDM切削效率的变化规律。仅通过增加脉冲能量（特别是脉冲宽度）来提高切割效率是困难的。在高速WEDM（HSWEDM）工艺中，超过75μs的脉冲宽度被证明对切削效率的提高影响很小。仅通过增加脉冲能量（尤其是脉冲宽度）来提高切割效率是困难的。在高速WEDM（HSWEDM）工艺中，超过75μs的脉冲宽度被证明对切削效率的提高影响很小。仅通过增加脉冲能量（尤其是脉冲宽度）来提高切割效率是困难的。在高速WEDM（HSWEDM）工艺中，超过75μs的脉冲宽度被证明对切削效率的提高影响很小。