Optimization of pulse on time to improve quality of microplate implants produced by EDM die-sinking

Producing microplates using electrical discharge machining (EDM) die-sinking still requires an extended processing time (T) of about 8,4 h, the surface roughness (R_a) level is below the implant standards around 5,85 μm, and the hardness (Hv) is lower than the raw material of around 131 Vickers hardness number (VHN). These three problems can be overcome by choosing the right pulse on time (T_on). This study aims to optimize the T_on parameter to improve the quality of the microplate produced by the die-sinking EDM. The microplate qualities observed were dimensional accuracy (DA), white layer (WL), surface roughness (R_a), and hardness (Hv). The T is observed by analyzing the material removal rate (MRR) that occurs during the EDM process. The study results show that microplates can be produced by EDM die-sinking with DA of 91% and an average WL thickness of around 9.6 µm. The resulting surface roughness complies with implant standards with an average R_a of 1.9 µm. The surface hardness of the microplate is above the hardness of the raw material with an average range of 214 VHN. The manufacturing process time can be accelerated to 5 h with an MRR of 0.224 mm³/min. The EDM die-sinking process is capable of producing the best quality microplates with a pulse on time parameter of 24 µs.