Abstract: Aiming at the problems that the micro-cutting mechanism of A-WEDM was not clear. Single-crystal silicons were used as the processing objects herein. The maximum discharge gap was measured by designing a circuit. The material removal mechanism of A-WEDM was studied by collecting and analyzing the discharge waveform, observing the surface topography of the workpieces, and comparing the height of the abrasive grain and the discharge gap. The effects of 4 factors(pulse width, duty cycle, feed speed and wire speed) on the material removal rate and surface roughness were investigated. The experimental results show that the maximum discharge gap is as 57 μm, i.e., in the initial stage of machining, discharge corrosion first occurs. When the machining is in stable stages, within each pulse width, the materials are removed under the coupling effects of discharge corrosion and diamond particle grinding. In each pulse interval, the discharge corrosion effect stops and the diamond particle grinding action still exists, thereby removing parts of the recast layer and craters.

Key words: single-crystal silicon, abrasion-assisted wire electrical discharge machining（A-WEDM）, discharge waveform, cutting mechanism

摘要： 针对目前磨削辅助电火花线切割（A-WEDM）微观切割机理尚不明确的问题，以单晶硅为加工对象，通过设计电路对最大放电间隙进行了测量。通过采集和分析加工中的放电波形、观测加工后工件表面形貌同时比较磨粒出刃高度与放电间隙的大小,研究了A-WEDM材料去除机理。考察了4个因素（脉冲宽度、占空比、进给速度和线锯速度）对A-WEDM切割单晶硅的材料去除率和表面粗糙度的影响。实验结果表明，A-WEDM切割单晶硅的最大放电间隙为57 μm，在加工的初始阶段先产生放电腐蚀作用；当加工处于稳定阶段时，在每个脉冲宽度内，工件材料在放电腐蚀与金刚石颗粒磨削的耦合作用下被去除;而在每个脉冲间隔内，放电腐蚀作用停止，金刚石颗粒的磨削作用仍然存在，从而去除了放电产生的部分重铸层与电蚀坑。

关键词: 单晶硅, 磨削辅助电火花线切割, 放电波形, 切割机理