Surface modi cation has been applied in many ways to enhance exclusive implant product. Electrical Discharge Machine Die Sinker (EDM DS) is a new approach to machine a macro surface on the biomaterial. In this study, investigations of current properties of EDM DS to obtain a new surface in titanium alloy (Ti-6Al-4V) and stainless steel (E-316-L), which placed pit on the material-sized (25 mm) diameter sample with a radius of 6.3 mm, were conducted. All the samples of concave textured circular

more »

... ts with a xed diameter and depth of 0.5 mm were successfully machined. This study revealed that the pits were produced in the concave cup and the lubricant was con ned inside the pits, making easier contact between metal ball and metal concave surface. The results also show that the discharge machine is an attractive machining method for surface modi cation of biomaterial. This paper suggests that concave implant surface embedded with pits will work as a trap for lubricant and wear debris; in addition, it is possible to increase the lifespan of implant structure.