Experimental investigation and optimization of surface roughness of β-Phase titanium alloy by ball burnishing assisted electrical discharge cladding for implant applications

Abstract

In the present research work, an attempt has been made to enhance the surface integrity (roughness and microhardness) of β-Phase Titanium Alloy using ball burnishing assisted electrical discharge cladding (BB-EDC) process. The effect of BB-EDC process parameters such as peak-current, pulse-duration, and supply-voltage on the surface roughness has been studied. For experimentation, a BB-EDC experimental set-up has been fabricated in-house on the Sparkonix die-sinking EDM machine. The experimentation has been performed according to a mixed-mode L-18 orthogonal array. The roughness was measured using a surface profilometer. The surface hardness was measured using Vicker’s microhardness tester. It has been observed that BB-EDC reduced surface roughness significantly and highest contributing factor. FE-SEM morphology investigation revealed that BB-EDC removed the surface irregularities and flat the surface, thus surface roughness decreased and finishing improved. Moreover, BB-EDC improved the surface hardness owing to comprise force generated by hard-ceramic balls. At optimized conditions, the minimum surface roughness and micro-hardness were measured around 0.61 µm and 848 HV, respectively. The obtained results show that the BB-EDC treated surface can be used for biomedical implant applications.