Investigation on MRR and Machining Gap of Micro Reciprocated Wire-EDM for SKD11

In this paper, the investigational work is carried out on the micro reciprocated wire electrical discharge machining (wire-EDM) of SKD11 using circularly travelled wire with phi 30 mu m as tool electrode, aiming to achieve the fabrication of micro parts with high cost-effect, efficiency and precision. The experiments are systematically performed using central composite design approach of response surface methodology to study the effect of open voltage, discharge capacitance, pulse duration and feed rate on material removal rate (MRR) and machining gap. The mathematical models of MRR and machining gap are developed by analysis of variance, and whilst verified by confirmation experiments with <= 8.38% and 6.70% prediction errors for MRR and machining gap, respectively. Besides, multi-objective optimization of parameter combinations is attempted by non-dominated sorting genetic algorithm-II. Finally, a typical experimental sample, micro gear is successfully machined with 1194.38 mu m tip diameter under the condition of No. 14 optimal solution.