The Bonding Mechanism of WC-12Co Coatings Prepared by Supersonic Plasma Spraying

WC-12Co coatings were prepared on polished steel substrate by supersonic plasma spraying. The microstructure and the bond mechanism of flattening particles and coatings were observed and analyzed by SEM. Bonding among coatings mainly belonged to mechanical bonding. Bonding between coatings and substrate mainly belonged to mechanical bonding,and partially belonged to metallurgy bonding, physical bonding and diffusion. WC could embed and grip the interior of substrate when high-speed incompletely melting particles impact onto substrate, consequently physical bonding was strengthened and the bonding strength between coatings and substrate was improved.