Anti-corrosion conversion coating compositions and methods for the same

A coated article, comprising:

• a substrate;
• a first coating layer comprising a rare earth element compound disposed upon at least a portion of the substrate;
• a second coating layer comprising a biopolymer disposed upon at least a portion of the first coating layer;
• a third coating layer comprising a rare earth element compound disposed upon at least a portion of the second coating layer;
• and
• a fourth coating layer comprising a biopolymer disposed upon at least a portion of the third coating layer;
• and
• wherein the rare earth element compound in the first coating layer and the rare earth element compound in the third coating layer are different.

A method for applying an anti-corrosive conversion coating composition, comprising:

• preparing a substrate;
• applying a first coating layer comprising a rare earth element compound upon at least a portion of the substrate;
• applying a second coating layer comprising a biopolymer upon at least a portion of the first coating layer;
• applying a third coating layer comprising a rare earth element compound upon at least a portion of the second coating layer;
• and applying a fourth coating layer comprising a biopolymer upon at least a portion of the third coating layer.