The C/C–Ti

3

SiC

2

composites were prepared by reactive melt infiltration (RMI) using TiC powder

Ti powder

Si powder

and Al powder as raw materials. The effects of different molar ratios of raw materials on the phase composition

microscopic morphology

flexural strength

thermophysical properties

and electromagnetic shielding effectiveness of the composites were investigated. The results show that the composites prepared with the ratio 1.8TiC/1.2Ti/1.4Si/0.2Al have a higher Ti

3

SiC

2

content and exhibit better mechanical properties

thermal conduct

ivity

and electromagnetic shielding performance: the flexural strength increases from 103.02 MPa ± 8 MPa to 150.50 MPa ± 7 MPa; the thermal conductivity ranges from 12.651 W/(m·K) to 15.193 W/(m·K) at temperatures from room temperature to 1000 ℃; and the electromagnetic shielding effectiveness increases from 21.40 dB to 26.68 dB in the 8.2–12.4 GHz frequency range. Analysis of the phase composition and microscopic morphology of three groups of samples reveals that as the TiC to Ti molar ratio decreases

the difficulty in forming Ti

3

SiC

2

gradually increases

mainly because the Ti content plays a key role in both the formation of the liquid phase during the reaction and the extent of the reaction.