Abstract
Titanium sapmles were immersed in hydrochoric acid, sulphuric acid, hydrofluoric acid, and chemical polishing bath (mixture of hydrofluoric acid and nitric acid) and the meltage, the surface roughness, and the surfece texture were examined. Warmed hydrochloric acid and sulphuric acid showed the solubility of titanium but their meltage were much smaller than the hydrofluoric acid and were found useless in practice. Hydrofluoric acid caused high meltage with a low concentration at room temperature, and was found useful to remove even the hardened layer of titanium castings in a short time. The chemical polishing bath did not cause much meltage but improved the surface roughness and surface texture, and was considered useful for the middle finishing of titanium prosthetics.
