Abstract
Electrochemical buffing, a combined process of electrochemical and mechanical polishing, was applied to titanium casting. Mixture of α-Al2O3 suspension (average grain diameter of 5μm) and 5% KNO3 solution was used as abrasive slurry. Specimen and experimental wheel buff were respectively connected to the positive and negative poles of a DC source, whose potential ratings ranged from 0V (MEP) to 10V (ECB10). Surface roughness, hardness, color, and cleanness were investigated. ECB10 surface produced a gold color and attained a mirror finish, as its roughness value was only one-quarter that of MEP. High amount of aluminum was present in MEP surface. Its bond state entirely differed from that of α-Al2O3, hence indicating surface alteration due to chemical reactions with the abrasive material. At higher potentials, reaction products might be dissolved anodically, so that the surface was chemically clean to some extent. The surface also became rich in OH-.
