Controlling color differences requires ensuring both material consistency and process stability.
On one hand, the composition of the die-casting alloy must be consistent across batches. For example, the content of elements such as silicon and copper in aluminum alloys should be controlled within a narrow fluctuation range. This is because variations in material composition directly affect the color results of subsequent surface treatments (e.g., anodizing). If surface coating (such as powder coating) is required, the compatibility between the alloy and the coating material must be verified in advance to prevent color differences caused by chemical reactions between components.
On the other hand, the parameters of the surface treatment process must be strictly controlled. For instance, during anodizing, the concentration of the electrolyte, electrolysis temperature, and electrolysis time should remain consistent across batches to avoid color inconsistencies in the anodized film due to parameter fluctuations. During die casting, the mold temperature should be controlled to prevent uneven cooling of different parts of the casting, which would result in uneven surface structure and subsequent color differences during treatment. For castings that undergo surface treatment after demolding, the surface must be thoroughly cleaned of release agents, oil stains, and other residues to avoid affecting the coloring effect and color uniformity of the subsequent surface treatment.
