Microstructure and mechanical properties of in situ produced SiC/TiSi2 nanocomposites

The microstructure and mechanical properties of in situ produced SiC/TiSi2 nanocomposites have been studied. The results indicate that SiC/TiSi2 composites can be fabricated by reactively hot pressing mixed powders of TiC, elemental Si and elemental Ti. The in situ produced SiC particles are close to nanosize. Without elemental Ti powder, the composite obtained consists of TiSi2 66 vol% and SiC 34 vol% without residual Si or TiC. At ambient temperature, the highest bending strength of SiC/TiSi2 composites was 400 MPa, twice that of monolithic TiSi2. Also fracture toughness of SiC/TiSi2 composites exceeds that of pure TiSi2. At 1200°C, the yield strength of composites was improved due to the presence of the SiC particles.