The Experimental And Application Study Of Electrical Discharge Small Hole Drilling In High-Speed Flow Field

High speed small hole electrical discharge based drilling（HSSHEDD）is widely used in aerospace,mold, hydraulic and other industries since its emergence due to high efficiency. However, surfacequality of the workpiece remains a key area for improvement while the high-speed is obtained. In thisstudy, a method of spray assisted HSSHEDD is proposed and successfully applied to the high speedEDM of carbon fiber reinforced resin matrix composites. The main contents of this paper are asfollows:1. On the basis of the establishment of the small hole electrical discharge drilling in high speedflow field, the high efficiency of HSSHEDD was studied by using numerical simulation and finiteelement analysis, which derived the flow state of the water-based dielectric in the machining gap. Itwas indicated that the high speed flow of the dielectric was the primary reason for high efficiency ofHSSHEDD. It is quick enough to flush out the generated particles and take away part of the heat fromthe gap, while keeping the machining conditions stable.2. The influence on the surface quality caused by spray system added to the HSSHEDD wasprimarily studied. Through thermal analysis with and without spay respectively, it showed that thespray would narrow the heat affected zone, therefore improving the surface quality.3. Through comparative tests it was verified that the spray would make positive effect on theimprovement of surface quality during the machining process. The influence of electrical parameteron the processing was studied.4. The spray assisted HSSHEDD method was applied on the electrical discharge drilling ofcarbon fiber reinforced plastic materials. It shows that the surface quality of the workpiece wassignificantly improved while increasing the processing speed to some extent. Hereby, a potentialenvironmental friendly and low cost approach is proposed to the machining of carbon fiber-reinforcedplastic laminates.