Black Chromate Zinc Magnesium: Cautious Corrosion Advice

Summary for black chromate zinc magnesium Discussion

Black chromate zinc contact with magnesium is discussed as a corrosion question, but the answer given is cautious: John notes that the outcome depends heavily on the environment and the exact part conditions. He asks whether the assembly is in a moist city or marine setting, whether the magnesium is treated, and whether the parts rub together, saying those details are needed before predicting galvanic corrosion. He does not identify any special “weird effect” from the silver in the black chromate itself, and instead recommends gathering more information about the application before drawing conclusions. Mike McDonald replies that he is looking for real-world experience with black chromate against magnesium and is trying to obtain magnesium for his own salt-spray testing. The thread ends without a definitive test result, so the practical takeaway is that corrosion risk cannot be judged from the finish alone.