Process and corrosion resistance of plasma-sprayed NiCoCrAlY/(Al_2O_3-13TiO_2) coatings on AZ91D magnesium alloy

摘要

Plasma spraying process was carried out to prepare NiCoCrAlY bonding coating and Al_2O_3-13%TiO_2 ceramic coating on AZ91D magnesium alloy by orthogonal experiments. The microstructural characteristics and properties of coating were investigated by SEM, tests of tensile, electrochemical method and weight loss. The results reveal that spraying power is the most important processing parameter to affect the bonding strength of the coating. The corrosion resistance of magnesium alloy is remarkably improved by plasma-sprayed NiCoCrAlY/(Al_2O_3-13%TiO_2) coatings, especially when the coatings were sealed with epoxy resin.