不锈钢微孔超声空化辅助钻削试验研究

Experimental Study on Ultrasonic Cavitation Assisted Micro Drilling of Stainless Steel

针对难加工材料微细钻削过程中排屑困难及微孔加工质量差的问题,提出微孔超声空化辅助钻削方法,分析了超声空化作用机理。通过高速摄像机观测超声空化过程,发现变幅杆端面形成了锥型空化区域,其作用范围达到10 mm以上。分别进行直径3mm和0.5mm的树脂工件空化钻削试验,发现超声空化效应均显著改善了切屑对刀具的黏附和缠绕现象。进一步进行了不同转速下不锈钢微孔超声空化钻削试验,利用激光扫描显微镜对微孔入口形貌、圆度、孔壁形貌和表面粗糙度进行检测。与普通钻削相比,超声空化钻削的孔径误差降低了8.5%~15.6%,入口圆度误差降低了20.0%~37.8%,孔壁粗糙度降低了12.7%~18.6%。结果表明,超声空化效应能够有效提高微孔钻削的加工质量和精度。

This paper proposes a micro-hole ultrasonic cavitation assisted drilling method to improve chip removal performance and micro-hole machining quality during micro-drilling of difficult-to-machine materials.The mechanism of ultrasonic cavitation is analyzed.Through the observation of ultrasonic cavitation process by high-speed camera,the taper cavitation area is formed on the end face of the horn,and its range of action reaches more than 10 mm.Cavitation drilling experiments of resin workpieces with diameters of 3 mm and 0.5 mm are carried out respectively,and it is found that the ultrasonic cavitation effect significantly improves the adhesion and entanglement of the chips to the cutter.Ultrasonic cavitation drilling experiments of stainless steel micro-holes with different spindle speeds are conducted.The entrance morphology,roundness,pore wall morphology and surface roughness of micro-holes are observed and measured by laser scanning microscopy.Compared with ordinary drilling,ultrasonic cavitation drilling reduces the aperture error by 8.5%-15.6%,the entrance roundness error decreases by 20.0%-37.8%,and the hole wall roughness decreases by 12.7%-18.6%.The results show that ultrasonic cavitation effect can effectively improve the quality and accuracy of micro-hole machining.