Laser cladding of SiC/Si composite coating on Si–SiC ceramic substrates

Pieces of silicon infiltrated silicon carbide (Si–SiC) were coated with a SiC particles reinforced Si matrix composite (SiC/Si) obtained from mixtures of SiC + SiO2 and SiC + Si by laser cladding. A Nd:YAG pulsed laser delivering an average power of 920 W was used to apply such coatings using the powder blowing technique. The results demonstrate that the use of the SiC + SiO2 powder mixture produces a severe damage on the base material, whereas the use of the SiC + Si mixture leads to the formation of sound coatings without substrate damage. XRD and nanoindentation measurements corroborate the production of silicon carbides surrounded by a metallic silicon matrix. This method could be used for repairing surface defects of silicon infiltrated silicon carbide ceramics (Si–SiC).