Search Results

The pretreatment of aluminum sheet material in preparation for further paint application can be challenging due to the presence of a thick oxide layer. The composition of the oxide layer is primarily aluminum oxide, but it may also contain magnesium that is typically dispersed unevenly throughout the oxide layer. Zinc-phosphate systems remove much of the oxide layer on aluminum, but questions remain on the extent of removal of the oxide layer by zirconium oxide-based pretreatments and how these oxide layers may affect the zirconium oxide-based pretreatment deposition on aluminum. Several methods have been used to characterize the coating of zirconium oxide-based pretreatments on aluminum. Scanning electron microscopy at very high magnification reveals a coating on aluminum that is significantly different in morphology than the same coating chemistry on steel substrates.