Surface Modification of SS316L using EDM process with Ti-6Al-4V alloy tool

SS316L is one of the cheaper solutions for biomedical applications, especially for making implants. However, its use in long-term applications is limited due to the emission of Ni + , Cr 3+ , and Fe 3+ , resulting in itching, eczema, cancer, and genotoxic-mutagenic effects. To solve this problem, the work modifies the surface of the SS316L workpiece by depositing tool material, made of Ti-6Al-4V alloy, on it using the EDM process. The process parameters, peak discharge current (I) and pulse-on time (T(ON)), were varied during the experiments, and corresponding effects on material deposition and on surface morphology were analysed. The results show that increasing the I enhances material deposition on the modified surface, makes it uniform and continuous, and improves the Ti content by removing Cr, Ni, and Fe. Similarly, increasing T(ON) to a certain value resulted in the deposition of more tool material, an increase in Ti content, and the creation of a more uniform and continuous layer on the modified surface. However, further increasing the T(ON) reduces the deposition of tool material, resulting in a surface with low Ti content. With an I of 10 A and a T(ON) of 100 μs, the highest Ti deposition in weight percentage was attained at 39.1. Additionally, by increasing I, surface roughness initially rises due to the formation of larger and deeper craters on the surface. However, it eventually decreases as the deposited material layer becomes more uniform. The increase in T(ON) contributes to greater surface roughness due to the creation of deeper and wider voids.