Systems and methods for treating a substrate

Abstract

Disclosed herein are systems and methods for treating a metal substrate. The system includes a first pretreatment composition comprising a fluorometallic acid and free fluoride and having a pH of 1.0 to 4.0 and a second pretreatment composition comprising a Group IVB metal or a third pretreatment comprising a lanthanide series metal and an oxidizing agent. The method includes contacting at least a portion of a surface of the substrate with the first pretreatment composition and optionally contacting at least a portion of the substrate surface with the second pretreatment composition or the third pretreatment composition. Also disclosed are substrates treated with one of the systems or methods. Also disclosed are magnesium or magnesium alloy substrates comprising a bilayer comprising a first layer comprising silicon and a second layer comprising fluoride.

Dependencies are inferred from the claim text.