Selected Problems of Electrodischarge Drilling of High Aspect Ratio Holes

Abstract

In the paper characteristic of drilling process of high-aspect-ratio holes is presented. The drilling of difficult-to-machine materials (such as hardened steel, carbides, alloys of high strength, composite materials, ceramics) is ineffective with application of conventional methods. The conventional methods are used to machine of materials with a relative machinability. The nonconventional methods are applied to the machine of holes in difficult-to-machine materials, especially in microscale. In the article is described electrodischarge drilling with using of deionised water which is called as hybrid process electrochemical discharge machining (ECDM). The hybrid process enables machining high aspect ratio holes by simultaneous interaction of anodic dissolution and electrical discharges. This paper also presents mathematical modelling of temperature increase during time of the impulse.