Effect of trace element additives on the microstructure and ablation properties of C/C-MoSi2-SiC composites fabricated by reactive melt infiltration

摘要

SiC is a suitable choice to improve the ablation resistance of C/C composites due to its good thermodynamic compatibility with carbon and excellent oxidation resistance. Reactive melt infiltration (RMI) is a successful methods to introduce SiC ceramics into the matrix of C/C composites which have advantages such as short fabrication period, low cost, near net shape, low porosity and so on. Si-Mo alloy have been used as infiltration instead of pure Si to eliminate the residual Si during the RMI process as Mo can react with Si to form MoSi2.It have been reported that C/C-MoSi2-SiC composites have excellent oxidation resistance before 1700°C.To improve the oxidation and ablation resistance under higher temperature, two kinds of trace element additives (Ti,Al) have been infiltrated together with Si-Mo into C/C substrate in this work, respectively.