Comparative Study of Corrosion Resistance of Cold Spraying Aluminum-Based Coatings on Magnesium Alloy

The study aims to determine the capabilities of cold spraying aluminum-based coatings to protect magnesium alloys from corrosion. Three aluminum-based powder mixtures – Al + Zn, Al + Al2O3, and Al + Zn + Al2O3 – were selected as the spraying material. Coating spraying was performed on prepared samples of magnesium alloy ML10 according to GOST 2856–79 using the DYMET-405 cold spraying machine. The corrosion resistance of coatings was tested in the salt chamber following ASTM B117. The mass loss of the samples was determined by weighing them before and after the tests. After nine days of testing, the mean value of mass loss of ML10 magnesium alloy samples without coating was 1.851 g, and 0.147 g, 0.13 g, and 0.141 g for samples with Al + Zn, Al + Al2O3, and Al + Zn + Al2O3 coatings, respectively. This indicates that cold spraying aluminum-based coatings do not have through porosity, are characterized by high adhesion strength to the substrate, and provide reliable protection of magnesium alloys against the influence of an aggressive corrosive environment. The scientific novelty of the obtained results is that the dependence of the corrosion resistance of the cold spraying aluminum-based coatings is obtained. The practical value is that the obtained results can be used to select powder material for cold spraying while developing technological processes for applying protective and restorative corrosion-resistant coatings.