Abstract: In this paper, the electrolytic polishing process of TC4 titanium alloy fabricated by selective laser melting was studied by using perchloric acid solution as the electrolyte. The effects of current density, electropolishing time, temperature, cathode material and other related parameters on the weight loss, surface roughness and thickness loss rate of the samples were investigated. The surface morphology of the polished samples was also analyzed. The results show that the effect of electropolishing using an electrolyte consisted of 10ml of perchloric acid, 100ml of glacial acetic acid and 12ml of water works well. The optimum parameters are as follows: current density of (0.27-0.37)A·cm^-2, temperature of (30-35)℃, and time of (15-20)min. After electropolishing, the surface roughness Ra of the sample decreased from 13.66μm to 1.52μm, and the thickness loss rate was about (6-7)%. The surface uniformity of the polished samples achieved ideal results.

Key words: Selective Laser Melting, TC4 Titanium Alloy, Perchloric Acid, Electrolytic polishing