医用C/C复合材料组织结构与应变率效应

采用X射线衍射仪和原子荧光分析仪对石墨化处理前后准三维C/C复合材料的石墨化程度及其所含的汞、砷、铅和镉元素含量进行了分析。在氩气保护条件下经过2400℃ 2 h石墨化处理的C/C复合材料所含以上元素含量较低， 更适宜作为外科植入材料使用。利用电子力学试验机在不同准静态应变率和加载方向条件下，对石墨化处理后C/C复合材料进行了压缩断裂试验研究，采用光学体视显微镜和扫描电子显微镜对该材料的断口形貌进行观察分析。结果表明，C/C复合材料具有压缩应变率效应，增强纤维阻止裂纹扩展和增韧效果明显。材料的抗压强度(28.30 MPa～83.25 MPa)和弹性模量(257.56 MPa～397.06 MPa)可以满足其作为骨修复材料的使用要求。 

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.