Investigations on Corrosion Behaviour in Micro-Milling of Biomedical Grade Ti–6Al–7Nb Alloy

Abstract

Titanium (Ti)-based alloy is extensively used in biomedical field due to its unique properties that promotes osseointegration. Present work deals with investigation on the effect of cutting conditions on corrosion resistance in micro-milling of Ti–6Al–7Nb alloy for enhanced biocompatibility. Experiments were carried out based on Taguchi L9 orthogonal array with selected process variables include cutting speed (vc), feed rate (fn) and depth of cut (ap). Micro-slot of size 700 µm for a length of 10 mm was made using high-speed micromachining station under wet condition. Potentiostat setup with three electrodes and simulated body fluid (SBF) at 37 °C was used for corrosion resistance measurement and corresponding Icorr values were obtained from polarisation curve. Icorr values are found to be minimum at higher vc and lower ap conditions. Variation in process parameters influences the surface characteristics to a greater extent, which intern alters the corrosion resisting potential of surface. From the study, it is observed that Ti–6Al–7Nb alloy exhibits higher corrosion resistance under in vitro condition for enhanced biocompatibility for medical application.