Cold-Sprayed Aluminum Coatings for Magnesium Aircraft Components

摘要

Cold spray was successfully employed to create a corrosion-resistant barrier coating of Al on a ZE41A-T5 Mg substrate and cold spray was demonstrated as a method of material restoration for Mg panels. Coatings of commercially pure Al, high-purity Al, AA5356, and AA4047 were produced. From electrochemical polarization to accelerated salt-spray testing (ASTM B117), the minimum coating thickness of commercially pure Al (18 mu m) required to provide an effective barrier was determined to be approx 0.38 mm. Commercially pure Al and high-purity Al coatings exceeded 500 h in the salt spray chamber. High-purity Al coatings provided the best galvanic compatibility with Mg, showing essentially no galvanic effect. Coatings of commercially pure Al, AA5356, and AA4047 exhibited galvanic currents almost 50 times greater.