Preparation and properties of glass coats containing SiCN nano powder as filler

A series of high-temperature glass coats with SiCN nano powder as the filler and the BaO-La₂O₃-B₂O₃ glass (BLB glass) as binder were prepared on the Ti-alloy substrates. The coefficients of thermal expansion (CTE) of the BLB glass in different temperature were determined by thermal mechanical analysis (TMA) and compared with those of Ti-alloy at the corresponding temperature. The tensile strength and the resistance to thermal shock of the different coats were investigated, and the effects of coating temperature and SiCN concentration in the coating materials on the properties of coats were discussed in detail. Results show that the tensile strength of coat without SiCN is much higher that those containing more or less SiCN. With the increase of SiCN content, the tensile strength of absorbing coat become worse, which could be attribute to the aggregate of SiCN in the coats. The breakage firstly happened inside the coat and then the interface of substrate and coat, indicating the bond strength of interface is higher that in the coat. The resistance to thermal shock of coat containing SiCN is much higher than those without SiCN, indicating that the addition of SiCN powder in the coat is helpful to improve the resistance to thermal shock.