Study on mechanical properties of high-temperature absorbing coats

SiCN nano-powder, a good high-temperature absorber, was introduced as the absorber into the BaO-La₂O₃-B₂O₃ glass to prepare the high-temperature absorbing coats on the Ti-based alloy substrates. The difference of thermal expansion coefficient between the glass and Ti-alloy was determined through thermal mechanical analysis (TMA) and the wet ability of the glass to the substrate was explored. The mechanical properties including the tensile strength and the resistance to thermal shock of the coats were investigated, and the effects of coating temperature and absorber content on the properties of coats were discussed. Results show that it is feasible to prepare the absorbing coat using the BLB glass as the binder. The BLB glass possesses good tensile strength and the introduction of the SiCN absorber into the glass coat will lower the tensile strength. With the increase of SiCN content, the tensile strength of the absorbing coat becomes worse, which could be attributed to the aggregate of SiCN in the coats. As the SiCN content increases, the resistance to thermal shock of the coats shows the tendency that increases firstly and then decreases. The glass coat containing the SiCN absorber possesses the better resistance to thermal fatigue than the glass coat without SiCN, indicating that the introduction of SiCN absorber in the glass could improve the thermal resistance of the coat.