Laser and furnace pyrolyzed organosilazane-based glass/ZrO2 composite coating system-A comparison

The laser pyrolysis of a ceramic coating system composed of an organosilazane (Durazane 1800) with monoclinic ZrO2 and glass particles as fillers was investigated. The samples were produced by spray coating on pre-treated stainless steel substrates and subsequently pyrolyzed by Nd:YVO4 laser radiation (lambda = 1064 nm). The interaction of laser radiation with the polysilazane-based glass/ZrO2 coating system led to formation of semi-crystalline dense coatings with a thickness up to 20 mu m in a short time. Laser pyrolyzed ceramic coatings were characterized and compared with furnace pyrolyzed coatings. The microstructure of the coatings was investigated by scanning electron microscopy (SEM). Additionally the corrosion resistance and mechanical properties, such as hardness, adhesive strength and the tribological behaviour have been investigated. Ceramic coatings generated by laser pyrolysis showing promising mechanical properties, a super-hydrophobic surface as well as a high corrosion resistance.