Basic Study of Combustion-Material Removal Process by Multi-Function Electrode

Abstract

Using the characteristic that most metal can burn in oxygen, put forward a new high-efficiency process that deals with the difficult-to-cut materials multi-function electrode EDM-induced ablation machining technology. Design the multi-function electrode and inject high-pressure oxygen and dielectric fluid rush to the machining area through it, then the gas and liquid are mixed as processing medium. During the machining process, first, surface material is removed by the electric spark discharge, which induces the combustion reaction between the metal and oxygen, generates very large amounts of combustion heat. Second, the combustion heat melts the difficult-to-cut metal and then turns the combustion reaction into a high-efficiency ablation reaction which is controlled by the density of the oxygen bubble dispersed by high-pressure water. The water-oxygen mixed medium is helpful for the interpolar deionization between the electrodes and the elimination of reaction products. Experiment has been conducted on machining titanium by combining this new technology with traditional electrical discharge turning (EDT). The result shows that the machining efficiency of this method can reach to 313mm3/min which is 4.3 times of the normal EDT machining efficiency. The experiment also shows that the machining efficiency heavily relies on the polarity effect during ablation process, the positive polarity machining efficiency is far higher than the negative polarity processing, and that the gas and liquid pressure difference should be controlled under a certain range. The characteristic of the combustion-material removal process with the multi-function electrode is also analyzed in this article.