抄録
It is well known that the mechanical properties of the anodic oxide coatings are materially improved by cooling electrolyte and increasing current density. But practically, the hardness and the wear resistance of anodic oxide coatings are greately influenced by anodizing conditions. Therefor, the composition of the electrolyte and electrical conditions are determined by the composition of the aluminium to be anodized, and it would be very convenient, if anodizing could work at higher bath temperature. So, a few consideration of the electrical conditions of sulfuric acid and sulfuric acidoxalic acid baths for aluminium and its alloys are herewith reported.
The hardness and wear resistance value increase with decreasing temperature and concentration, and increasing current density, but 17 S alloy indicates a lower value under a lower temperature and higher current density. The addition of oxalic acid to sulfulc acid baths improved the mechanical properties at higher temperature electrolysis though not at lower temperatures. So far as the present experiments are concerned, there seemed no close relationship between the hardness and the wear resistance, but it was found that the higher the scratch hardness, the higher was the wear resistance.
