Microstructure and mechanical properties of C/C composite bolts

Using laminated carbon cloth with punctured carbon fibers as preform, high density C/C composites were prepared by thermal gradient chemical vapor infiltration (TCVI) technology. C/C composites bolts were fabricated by machining processing along different fiber reinforced direction. The methods were proposed to evaluate mechanical properties of C/C composite mechanical joints and the mechanical properties were measured by special clamps. The microstructure and rupture morphology were observed and analyzed by polarization microscope (PLM) and scanning electron microscope (SEM). The results show that C/C composite bolts machined along the direction of carbon cloth (xy direction) have better mechanical properties. The tensile strength and shear strength of C/C composite bolts are 52.3 MPa and 49.8 MPa respectively. The shear strength of C/C composite straight pin is 52.2 MPa.