Microstructure and properties of plain-weave carbon fabric reinforced ceramic composites containing Cu-Si alloy

Aiming to improve the physical properties, the soft Cu3Si phase was successfully introduced into C/C-SiC composites to partially replace SiC and residual Si via a simultaneously infiltration of Si and Cu. The microstructure and physical properties of the as-prepared C/C-SiC-Cu3Si composites (CSCS) were investigated in comparison to the C/C-SiC composites with same fiber architecture. The results indicated that the thermal diffusivity of CSCS is improved from 8.32 to 11.02 mm2/s, while both SiC and Si content in CSCS composites were obviously reduced to 23.2 wt% and 10.8 wt%, respectively. Moreover, compared to the C/C-SiC, the flexural strength which is fiber-dependent is significantly enhanced, while the compressive strength which is matrix-dependent is slight decreased in CSCS. The microstructural investigations revealed that fibers with less aggressiveness by liquid silicon and lower capacity to uniformly deformation of matrix in CSCS are main reasons for higher flexural strength and lower compressive strength, respectively.