Microstructure and properties of cold sprayed aluminum bronze coating on MBLS10A-200 magnesium-lithium alloy

Abstract

Aluminum bronze coatings were prepared on MBLS10A-200 magnesium-lithium alloy substrate by cold spraying technology to improve the surface properties of Mg–Li alloys. The microstructure, phase composition, microhardness, tribological properties and corrosion resistance of the coatings were systematically analyzed. The results show that aluminum bronze coatings are mainly composed of α phase. β phase in the original aluminum bronze powder disappeared in the coating due to the eutectoid transition of β→α + γ2 during the cold spraying. Compared with the Mg–Li alloy substrate, the aluminum bronze coating exhibits the higher microhardness (222.88 HV0.3) and wear resistance (friction coefficients, wear track widths and wear mass losses are 0.37, 0.79 mm and 2.47 mg, respectively). The dominant wear mechanism of the coatings was abrasive wear. In the electrochemical test, the corrosion current density of the aluminum bronze coating (3.07 × 10−5 A/cm2) was an order of magnitude lower than that of Mg–Li alloy substrate (6.15 × 10−4 A/cm2), indicating that the coating had superior corrosion resistance. The above analysis confirms that preparing a cold sprayed aluminum bronze coating has outstanding tribological and corrosion resistance properties.