1：Experimental Design and Method Selection:

The study used spark plasma sintering (SPS) to produce ceramic composite materials (CCM) with SiC matrix and additives like B4C, AlN, Si3N4, Y2O3, Al2O3, and HfB2. Thermophysical properties (specific heat, thermal diffusivity, thermal conductivity) were measured in the temperature range 20–1300°C using laser flash method, differential scanning calorimetry (DSC), and adiabatic calorimetry. Thermal conductivity was calculated from measured thermal diffusivity, specific heat, and density.

2：Thermophysical properties (specific heat, thermal diffusivity, thermal conductivity) were measured in the temperature range 20–1300°C using laser flash method, differential scanning calorimetry (DSC), and adiabatic calorimetry. Thermal conductivity was calculated from measured thermal diffusivity, specific heat, and density. Sample Selection and Data Sources:

2. Sample Selection and Data Sources: Samples were prepared from silicon carbide powder (F 1200) with average particle size 4 μm, silicon carbide whiskers (SiCw from Viking JSC), and additives with specified particle sizes. Compositions included various volumetric percentages of SiC with different additives.

3：List of Experimental Equipment and Materials:

Equipment included a hybrid spark plasma sintering apparatus (model H-HPD 25-SD, FCT, Germany), pyrometers (IGA6), electronic balance (GR-200, AND, Japan), laser flash apparatus (LFA 427, Netzsch, Germany), adiabatic calorimeter (SH-3000M, Sinku-Riko, Japan), and differential scanning calorimeter (DSC 404 F1, Netzsch, Germany). Materials included SiC, B4C, AlN, Si3N4, Y2O3, Al2O3, HfB2 powders, platinum for coating, and graphite for blackening.

4：Experimental Procedures and Operational Workflow:

Samples were sintered using SPS at 100 K/min heating rate in argon flow at 1650–1800°C. Density was measured by hydrostatic weighing. Thermal diffusivity was measured by laser flash method on platinum-coated samples. Specific heat was measured by laser flash, DSC, and adiabatic calorimetry. Thermal conductivity was calculated using the formula λ = a * Cp * ρ.

5：Data Analysis Methods:

Data were analyzed using least-squares method to fit expressions for specific heat and thermal conductivity. Thermal conductivity was compared with theoretical values using E. Ya. Litovskii's method.