Performance evaluation of micro-dimple formation on a Ti-6Al-4V alloy by using electrical discharge drilling

Micro-dimple formation improves the tribological behavior of a material. This study investigates dimple formation on a titanium (Ti-6Al-4V) alloy by using electrical discharge drilling. Input parameters, namely capacitance (C), pulse-on-time (Ton), and voltage (V), were varied to measure the output quality responses including dimple depth, burr height, and burr width. The experimental results indicated that the quality of the dimple is determined based on the spark energy and rate of material removal. A regression analysis was performed for each output response. The developed model confirmed the fitness at a 95 % confidence interval. The contribution of each factor and its significance was determined by using analysis of variance (ANOVA). Further, the optimum drilling condition was predicted by using desirability analysis (C = 10000 pF, Ton = 100 μs, and V = 180 V). The microscopic view of the dimple array and the micro-dimple geometry were analyzed by using scanning electron microscopy images.