Effect of Reaction Sintering Time
The influence of RS duration on the density of SiC-Si-C ceramics is shown in Figure 4. The density of ceramics was increased by increasing the RS time. The rate of increasing in the density is higher for specimens prepared from n-SiC compared to that of μ-SiC. Again, the density was reduced by increasing the Si content. Figure 5 illustrates the microstructure of ceramic specimens processed for 2 and 4 h at 1400°C. It is clear that the amount of porosity was reduced at longer times of RS. It is important to note that unreacted Si and C phases were present even after RS for 4 h (Figure 5(b)). As it can be seen in Figure 3, XRD patterns show β-SiC reflections only after 4 h RS at 1400°C.