Finite element design of SiC/C functionally graded materials for ablation resistance application

Summary c finite element numerical models are used to study residual thermal stresses induced during cooling from the sintering temperature of carbon-based SiC/C functionally graded materials (FGMs) for ablation resistance application. Results show that the stresses can be decreased gradually with increasing the layer number (N). In a preferred system, the optimum compositional distribution exponent (P) and thickness of intermediate graded layers and pure SiC layer are 1.0, 3.6 mm and 1.0 mm, respectively. On basis of the simulated results, SiC/C purpose FGM was fabricated by hot-pressing process. SEM observation shows that this material is characterized by a linearly continuous gradient in the microstructure. Further studies indicate that this material has excellent ablation and thermal shock resistances.