Influence of pyrocarbon amount in C/C preform on the microstructure and properties of C/ZrC composites prepared via reactive melt infiltration

•The densification of C/ZrC became more difficult with more pyrocarbon in preform.•ZrC content in C/ZrC composites decreased from 35.3 vol.% to 6.3 vol.%.•The σf and E of C/ZrC from preform with 34.1 vol.% pyrocarbon are 181 MPa and 13.0 GP.•The mass loss and linear recession rate of C/ZrC are 0.0031 g/s and 0.0012 mm/s.

C/ZrC composites were prepared via reactive melt infiltration with zirconium from porous C/C preforms with various pyrocarbon contents. As the pyrocarbon amount in C/C preform increased from 34.1 vol.% to 61.7 vol.%, the densification of C/ZrC composites was hindered and the ZrC content in C/ZrC composites decreased gradually from 35.3 vol.% to 6.3 vol.%. Meanwhile, the flexural strength of C/ZrC composites decreased initially and then increased, but the flexural modulus rose continuously. The flexural strength and modulus of the composites fabricated from the preform with 34.1 vol.% pyrocarbon matrix were 181 ± 4 MPa and 13.0 ± 1.2 GPa, respectively, and the mass loss rate and linear recession rate were 0.0031 g/s and 0.0012 mm/s, respectively.