Abstract:
By means of scanning electronic microscope (SEM),laser scanning confocal microscope (LSCM) and mechanical properties measuring,the microstructure morphology and the compressive mechanical properties of the 3D C/C composite along x,y and z directions were studied. The results show that there are obvious defects,and there is weak adhesion in the fiber/matrix interface of the 3D C/C composite. The compressive strength and fracture strain along z direction are all much greater than those along x direction and y direction. The compressive fracture mechanism of 3D C/C composite was also investigated based on the macro-pictures of the fracture surface of specimens. The results show that the compressive stress-strain curves exhibit the almost linear characteristics at the beginning,and show nonlinear characteristics with the time. Failure models of the samples under compressive load along x,y and z directions present shear fracture. The fiber/matrix interfacial strength has a great effect on the compressive failure mechanism.