Influence of microstructure of alloy on the machining performance of micro EDM

Electrical discharge machining (EDM) is an electro-thermal process. When a micro feature is of the same size order as microstructure of alloy, the machining performance of micro EDM varies due to the difference between the thermal properties of the crystal grain and that of the granular boundary, resulting in undesired dimensions and unstable machining process. To improve the machining accuracy and efficiency of micro EDM, it is necessary to understand the influence of microstructure of alloy on the machining performance of micro EDM. In this study, micro holes were drilled in titanium alloy with equiaxed crystals, copper, nickel, nickel-copper alloy and stainless steel with enlarged grains. Different average values and distribution ranges of material removal rates and discharge gaps indicate that the machining performance of micro EDM is influenced by the microstructure of alloy. (C) 2012 Elsevier B.V. All rights reserved.