Microstructure, Mechanical Property and Corrosion Behavior of Cold-Sprayed Zn Coatings on Mg Alloy Substrate.

Zn coatings on Mg alloy substrate were prepared by in-situ micro-forging-assisted cold spraying with different stainless steel shot additions. Phase, microstructure, mechanical properties and corrosion resistance of Zn coatings were investigated. The results show that the shot addition enhanced the ZnO formation and increased the full width at half maximum of the Zn phase in the Zn coatings. Plastic deformation of Zn particles was enhanced with the coating densities. Microhardness of Zn coatings was increased due to work hardening, grain refinement and densification by the hammering effect of shots. Bond strength was increased and fracture surfaces showed both metallurgical bonding and mechanical interparticle interlocking in Zn coatings. Zn coatings effectively improved the corrosion resistance of the Mg alloy substrate, and the shot addition made a small contribution to the corrosion resistance. The corrosion behavior of Zn coatings was discussed in terms of corrosion products and microstructures after immersion. [ABSTRACT FROM AUTHOR]