ANTICORROSION PROPERTIES OF Zn–Al–Mg–ZnO COMPOSITE COATING PREPARED BY COLD SPRAYING

Abstract

Two kinds of composite coatings, Zn[Formula: see text]Al[Formula: see text]Mg5ZnO[Formula: see text] and Zn[Formula: see text]Al[Formula: see text]Mg5ZnO[Formula: see text], were prepared on steel matrix (Q235) by cold spraying. The Zn, Al, Mg, and ZnO in raw materials were calculated by percentage of mass. The morphology of the original coating was observed by scanning electron microscopy (SEM) and characterized by energy dispersive spectroscopy (EDS). It was found that the microstructures of Zn[Formula: see text]Al[Formula: see text]Mg5ZnO[Formula: see text] and Zn[Formula: see text]Al[Formula: see text]Mg5ZnO[Formula: see text] composite coatings prepared by cold spraying were compact without oxidation products, and the plastic deformation of powder particles was significant. The friction and wear test data of the two coatings showed that the Zn[Formula: see text]Al[Formula: see text]Mg5ZnO[Formula: see text] coating had longer-lasting protective properties and wear resistance under the same conditions. Neutral salt spray test (NSS) and electrochemical accelerated corrosion test were carried out on samples at different time periods. The results of samples’ corrosion microstructure and electrochemical curves showed that Zn[Formula: see text]Al[Formula: see text]Mg5ZnO[Formula: see text] and Zn[Formula: see text]Al[Formula: see text]Mg5ZnO[Formula: see text] have good electrochemical protection performance, and Zn[Formula: see text]Al[Formula: see text]Mg5ZnO[Formula: see text] coating has better protection effect.