Environment-friendly electropolishing of titanium alloys

The titanium alloy surface was polished in a recently self-developed electrolyte.The morphology of the polished alloy surface was characterized by optical microscopy(OM) and atomic force microscopy(AFM).The electrolyte was made of alcohol,lactic acid,perchloric acid and sodium perchlorate instead of those poisonous compositions such as hydrofluoric acid,methanol and chromate.The alloy surface was polished in the solutions containing perchloric acid of 5%,10% and 15% in volume fraction at different current densities of 20,25 and 30 A·dm-2,respectively.The corrosion rate was estimated by using weight loss method.The thickness of the removed surface layer was dependent upon polishing time,current density and the concentration of perchloric acid.It was shown that the 5% perchloric acid and 20 A·dm2 current density were good to electropolishing of the titanium alloy.