A component (17) made of an aluminum silicon cast alloy whose surface is at least partly subjected to an anodic treatment to produce an oxide layer, which component comprises, prior to the anodic treatment, a surface-proximate deformation zone (4) configured as a homogeneous zone in which the silicon is uniformly distributed in the .alpha.-mixed crystal (1) and due to this homogeneous mixing of aluminum and silicon, the differing electric conductivities of the original structural constituents (.alpha.-mixed crystal, eutectic) are replaced by a uniform electric conductivity so that uniform oxide layers can grow during the anodizing process.