Structures and strain rate effect of biomedical C/C composites

The graphitization degrees of quasi-3D C/C composites were analyzed through X-ray diffractometer, and the element contents of hydrargyrum，  arsenic，plumbum and cadmium in the materials were determined by the atomic fluorescence analyzer. For the C/C composites that have undergone 2400℃ 2 h graphitization heat treatment under the protection of argon，the content of the above-mentioned elements is relatively low. In this light，the heat-treated C/C composites are more applicable for surgery implantation. The compression fracture experiments on the graphitized C/C composites were carried out on the electronic mechanical test machine under the condition of different loading rates and different loading directions. Then the fracture morphologies were observed by means of SEM and the stereological optical microscope. All the results reveal that quasi-3D C/C composites have strain rate sensitivity and the reinforced fibers have remarkable effects in arresting propagating cracks and plasticizing. The compressive strength(28.30 MPa～83.25 MPa) and elastic modulus (257.56 MPa～397.06 MPa) could satisfy the mechanical demands of bone-repairing materials.