Agglomerated ZrB 2-MoSi 2 composite powders with different contents of MoSi 2 were successfully prepared by spray drying and vacuum sintering. Then ZrB 2-MoSi 2 composite coatings were deposited on C/C composites by atmospheric plasma spraying (APS) using ZrB 2-MoSi 2 composite powders with average size of 30 μm as raw material. The microstructure and anti-oxidation performance of coatings were characterized by XRD, SEM, etc. It could be found out that the microstructure of ZrB 2-MoSi 2 composite coatings was dense with bonding strength up to 7.2 MPa. And oxidation-resistance of composite coating at high temperature could be improved by appropriate addition of MoSi 2. The weight loss of C/C composites coated by ZrB 2-40wt%MoSi 2 coating was only 1.7% after 9 h in air at 1500℃. The coating exhibited good self-sealing performance and excellent anti-oxidation ability.

The results obtained by our simulations can provide effective guidance for the design of nanoparticle-grafted bimodal bidisperse polymer chains and provide a theoretical basis for experimentation and production of polymer nanocomposites with better performance.

The agglomerated ZrB2-MoSi2 composite powder was prepared by spray drying and sintering. The spray-dried ZrB2-30wt%MoSi2 (SZM) composite coating was manufactured by low pressure plasma spray (LPPS) using the agglomerated powder. For comparison, the mechanically-mixed ZrB2-30wt%MoSi2 (MZM) composite coating was also prepared by LPPS. The composite powders and the coatings were characterized by X-ray diffraction and scanning electron microscopy. The flowability and the loose density of the agglomerated powders were measured by Hall flow meter and loose density instrument, respectively. Microhardness, porosity and oxidation behavior of the coatings were also investigated. The results show that when the spray-dried powder is sintered at 1200 °C for 1 h, its flowability and loose density are up to 25.8 s/50 g and 1.12 g/cm 3 , respectively. The distribution of MoSi2 phase in SZM coating is much more uniform than that in MZM coating. Additionally, the SZM coating exhibits a high compactness and much better oxidation-resistance at 1500 °C compared to the MZM coating.