On Productivity of WSEM Process for Manufacturing Meso-Sized Helical and Bevel Gears

This paper reports on productivity of wire spark-erosion-machining (WSEM) process for manufacturing meso-sized helical gear (MHG) and meso-sized bevel gear (MBG). Productivity of WSEM process is measured by volumetric gear cutting rate (VGCR). Variation in VGCR with four WSEM parameters such as servo voltage 'S_V' pulse-on time 'T_on', pulse-off time 'T_off', and feed rate of wire 'W_F' is also studied. Box-Behnken design approach of Response Surface Methodology (RSM) was used to design and conduct 29 experimental runs with replicates twice for analysis of VGCR. Analysis of variance (ANOVA) was used to determine the significant parameters and their interactions. It was observed that all considered WSEM parameters are significant and considerably affect VGCR. Desirability function analysis was used to find the optimum WSEM parameters so as to enhance the productivity of WSEM process to manufacture the better quality of MHG and MBG. Confirmation experiments were performed to validate the optimized values of VGCR corresponding to MHG and MBG and achieved much closer to it. Scanning electron micrographs (SEM) of MHG and MBG revealed uniform and burr-free tooth profile, bore and smoother cracks-free flank surfaces. (paper)