WEDM microdrilling of 316 L stainless steel orthopedic implant

Abstract

The development in manufacturing has insisted upon the fabrication of microdrilled holes on orthopedic implants, with finished side wall (devoid of cracks and burr), thin recast layer, low taper, and improved circularity at entry and exit of the hole. In this study, therefore, a multiobjective optimization of wire electric discharge machining microdrilling response characteristics is addressed in order to improve the hole quality characteristics and viability of implants. To improve the quality characteristics of the hole, a hybrid statistical analysis is developed based on grey relational analysis and coefficient of variation. It identifies the key process parameters that are responsible for improving the quality of the hole. The parametric study also reveals that wire feed rate and servo feed rate have a striking effect on the quality of the hole. An important implication of this study is that a thin recast layer, improved entry and exit circularity, adequate taper were observed under optimum drilling condition.