Microstructure and corrosion behavior of ZrO2 coated carbon fiber reinforced magnesium matrix composites sprayed with different powder characteristics

Abstract

To explore the influence of powder characteristics on the microstructure and corrosion resistance of supersonic atmospheric plasma sprayed ZrO2 coated carbon fiber reinforced magnesium matrix (Cf/Mg) composites, three kinds of powders with different structures and particle sizes were designed. The formation mechanism of coating defects induced by the different powders was explored by analyzing the melting and solidification processes of powders. The electrochemical test revealed that ZrO2 coated Cf/Mg composites sprayed with incompletely compacted interior and particle size of 25–40 μm had the lowest corrosion current density (4.22 × 10−5 A cm−2), as this powder was easier to melt completely to develop a dense coating that could effectively resist the attack of corrosive solution.