微细电火花加工中电极损耗较大,在加工大深径比微细孔时,工具电极和工件之间的狭窄间隙内流体阻力较大,气泡及加工屑不易排出,易产生频繁的非正常放电,导致电极损耗进一步增大.针对大深径比微细孔加工的这一难题,提出采用电极摇动同时在工件上加载超声波振动的新方法,成功地在3.5 mm厚的不锈钢板上加工出平均直径为120 μm的通孔,深径比达29.%When a micro-hole is drilled deeply by EDM, the viscous resistance in the narrow discharge gap causes difficulty in the removal of debris and bubbles from the working area, leading to frequent occurrences of abnormal discharges and resulting in extensive electrode wear. This paper presents a new method of drilling high aspect ratio micro-holes by EDM, in which the planetary movement of an electrode, with enhancement from ultrasonic vibration, provides an unevenly distributed gap for the debris and bubbles to escape from the discharge zone easily. Micro-holes with aspect ratio of 29 have been drilled with an average diameter of 120 μm in stainless steel 304 with a thickness of 3.5 mm.
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