Composite coatings of Si3N4-soda lime silica produced by the thermal sprayprocess

Silicate glass and glass-silicon nitride composite coatings were atmospheri c plasma sprayed onto mild carbon steel substrates under varying process pa rameters such as torch pow-er and H-2/Ar ratios. The x-ray analysis reveale d that Si3N4 in the composite coatings could be preserved under the harsh e nvironmental conditions of the plasma spray process. The presence of Si3N4 as the reinforcement phase to the glass matrix conferred higher hardness pr operties to the coatings.