Reaction-bond sintering of C/SiC functionally graded nanostructured materials (FGNMs)

In this study, bulk C/SiC functionally graded nanostructured materials (FGNMs) having a compositional gradient from carbon (C) to silicon carbide (SiC) were obtained by applying the powder-stacking method under pressureless sintering condition. During the sintering process, the reaction-bonded SiC was formed in the presence of pure silicon (Si) which led to increase in the density and strength of the FGNMs. At the sintering stage, the compacted bodies were heated at 1525 °C for 2 h in an argon atmosphere. Results showed that the number of graded layers had a marked effect on the microstructure and properties of the sintered C/SiC FGNMs. With increasing number of graded layers, the bend strength of the samples improved significantly. Moreover, SEM micrographs illustrated that the formation of SiC nanorods between adjacent particles improved the bending strength of the samples.