Experimental research on preparation and machining performance of porous electrode in electrical discharge machining.

The present describes a porous electrode for electrical discharge machining (EDM) that can decrease the concentration of corrosion products in the discharge gap. The electrode is prepared by high-temperature sintering of copper particles. A large number of red copper particles become connected together through sintering necks to form a structure with a large number of pores that act as flushing channels. By exploring the preparation method, material, sintering temperature, and holding time, a porous electrode is prepared such that copper particles do not fall off during the discharge process. The flow of the flushing medium is simulated in the porous electrode, and the action of the flushing flow field in the discharge gap on erosion products is identified. In agreement with the simulation results, experimental results for the EDM of the titanium alloy Ti6Al4V show that the material removal rate with a porous electrode is 3 times higher than that for traditional EDM with a solid electrode. Moreover, the electrode wear is lower due to the effective discharge of the corrosion products by the flushing liquid. Experimental results when rough machining a complex semi-closed cavity show that the porous electrode can greatly shorten the machining time by 47 %, which demonstrates that a porous electrode improves the machining of a complex cavity in a titanium alloy. [ABSTRACT FROM AUTHOR]