Mechanical properties of polymer-derived ceramic composite coatings on steel

Polymer-derived ceramics have shown promise as a novel way to process low-dimensional ceramics such as fibers and coatings. A polymer-derived ceramic composite coating on steel as a barrier to oxidation and carburization has been developed using poly(hydridomethylsiloxane) as the matrix and titanium disilicide as the filler. Processing parameters have been optimized and coatings of ∼18 μm thick and a density of 2.57 g/cm3 have been produced. This paper presents the results of mechanical testing of the coating and the coating–steel interface. The hardness of the coating after pyrolysis to 800 °C was determined to be 4.8 ± 1.0 GPa and the modulus in the range of 49–54 GPa. The tensile strength of the coating was 1.9 GPa and the ultimate shear strength of the interface was found to be 2.35 GPa.