Preparation and characterization of SiO₂/carbon foam and SiC/carbon foam composites

The synthesis and characterization of carbon foam supported silica aerogel (SiO₂/Carbon foam) and silicon carbide composite (SiC/Carbon foam) are presented in this study. The phase composition’ microstructure, thermal and mechanical properties are investigated by XRD, SEM, LFA Laser Flashmeasurements, and Universal Material Testing.The resulting SiO₂/Carbon foam composite shows a higher compressive strength (14.95 MPa) and a smaller thermal conductivity (0.44 W•m^-1•K^-1) at room temperature’ in comparison with the pristine carbon foam. The SiC/Carbon foam composite maintains a compressive strength of 14.66 MPa’ and possesses a low high- temperature thermal conductivity (2.18 W•m^-1•K^-1 at 1 200 °C). Mass loss does not begin until 610 °C for the SiC/Carbon foam composite’ and complete carbon combustion does not occur until 844 °C, indicating a much better thermal stability than the pristine carbon foam in oxidizing atmosphere.