Abstract
One of the practical and low cost treatments, an electrolytic polishing (EP) was applied to aluminum alloys for vacuum equipment use to optimize polishing condition utilizing the Taguchi Methods by small samples. EP samples prepared at the optimal conditions, i.e. high temperature of the polishing liquid and the first rinse water, had outgassing rate as low as chemical polishing (CP). Uniformly thinner and dense surface oxide barrier layer and thicker porous columnar oxide surface layer were the product of the optimal and the starting EP treatments, respectively, and they corresponded to lower and higher outgassing quantity, respectively. Pumping time dependence of outgassing rate q of EP and CP treated chamber samples showed that the formers were higher than the latter, respectively. At ultimate pressure q of EP and CP samples are 3×10-12 Pa·m·s-1 and 1×10-12 Pa·m·s-1, respectively.
