MANUFACTURING METHOD OF ALUMINUM CASTING ALLOYS WHICH HAS A BLACK COLOR FOR HARD ANODIZING

摘要

PURPOSE: A manufacturing method of aluminum casting alloys which has a black color for hard anodizing is provided to manufacture uniform black product by anodization under 7°C of temperature of an electrolyte. CONSTITUTION: A manufacturing method of aluminum casting alloys which has a black color for hard anodizing is as follows. Alloy contain silicon 1.0~8.0wt.%, titanium 0.002~0.3wt.%, impurity, aluminum. Heat-treatment is performed in 300~550°C for 5 minutes ~3 hours. The alloy is anodic oxidized in the electrolyte temperature 7°C or less.