Abstract
The effect of alloying elements on the hardness of anodized films on aluminum has been investigated, in the hope that some new high tensile strength alloys having hard oxide films might be developed. Al-binary alloys were anodized in three typical electrolytes and micro Vickers hardness of the films were measured. With respect to the relationship between the hardness of the films and the alloying elements, three different types were observed: (1) Si, Cr, Cu and Mg cause the decrease in the film hardness with increasing contents of the alloying elements. (2) Be, Zn and Mn initially decrease the hardness but finally constant values are obtained. (3) The hardness of Al-Zr alloy film is larger than that of pure aluminum.
