High-temperature mechanical properties and microstructure of 2.5D C/ C-SiC composites applied for the brake disc of high-speed train

This paper uses chemical vapor infiltration method to prepare 2.5D C/C-SiC composites, and conducts various tests to reveal its high-temperature mechanical properties and failure mechanism. The results show that the test temperature significantly affects the mechanical properties. As the test temperature increased from room temperature to 800 degrees C, the tensile strength of the 2.5D C/C-SiC composite dropped from 127.67 +/- 20.87 MPa to 94.74 +/- 28.15 MPa, and the performance dropped by 25.79 %. The compressive strength dropped from 326.92 +/- 17.37 MPa to 192.31 +/- 29.15 MPa, resulting in a performance decrease of 41.18 %. The bending strength dropped from 355.74 +/- 40.80 MPa to 235.88 +/- 23.52 MPa, and the performance dropped by 33.69 %; the interlaminar shear strength dropped from 9.77 +/- 2.79 MPa to 7.80 +/- 3.26 MPa, and the performance dropped by 20.16 %. High-temperature oxidation will lead to interface degradation, destroy the composite matrix and carbon fiber structure, change the interface bonding strength, and ultimately lead to a decline in composite performance.