【摘要】 通过化学气相渗积法(CVI)制备C/C多孔体，经高温热处理后，利用反应熔渗法(RMI)制得C/C-SiC复合材料。通过设置1 600,1 800,2 200℃3个温度点对C/C多孔体进行高温热处理，研究了中高温区间的变化对C/C-SiC复合材料微观结构和性能的影响。结果表明：通过对C/C多孔体热处理，可以改善基体炭结构，Si晶体的衍射峰偏移可能受到内应力的影响；随着热处理温度的增加，C/C多孔体的孔隙率和石墨化程度不断上升，C/C-SiC复合材料孔隙率不断下降，SiC含量不断上升，2 200℃前热处理下C/C-SiC复合材料孔隙率由6.57%降低至3.29%,SiC基体含量由26.93%升高至40.32%,未经前热处理的C/C-SiC复合材料最大弯曲强度为258.07 MPa,表现出一定脆性特点，经1 800℃前热处理的C/C-SiC复合材料弯曲强度值最高，达到303.02 MPa, 2 200℃前热处理后C/C-SiC复合材料弯曲模量最大为38.24 GPa,但强度没有显著提高，原因可能是高温对纤维的损伤作用削弱了纤维的强度。更多还原

【Abstract】 C/C porous bodies were prepared by chemical vapor infiltration(CVI),and then subjected to high-temperature heat treatment.Subsequently, C/C-SiC composites were fabricated by reaction melt infiltration(RMI).The effects of changes in the medium and high-temperature range on the microstructure and properties of C/C-SiC composites were investigated by setting three temperature points of 1 600,1 800,and 2 200 ℃ for high-temperature heat treatment of C/C porous bodies.The results show that the pre-heat treatment of C/C porous bodies can improve the structure of the matrix carbon, and the shift of the Si crystal diffraction peak may be affected by internal stress.With the increase of pre-heat treatment temperature, the porosity and graphitization degree of C/C porous bodies continuously increase, while the porosity of C/C-SiC composites continuously decreases and the SiC content continuously increases.After pre-heat treatment at 2 200 ℃,the porosity of C/C-SiC composites decrease from 6.57% to 3.29%,and the SiC matrix content increases from 26.93% to 40.32%.The maximum flexural strength of C/C-SiC composites without pre-heat treatment is 258.07 MPa, showing certain brittle characteristics.The C/C-SiC composites pre-heat treated at 1 800 ℃ have the highest flexural strength of 303.02 MPa.After pre-heat treatment at 2 200 ℃,the flexural modulus of C/C-SiC composites is the largest, reaching 38.24 GPa, but the strength dose not increase significantly, possibly due to the damage effect of high temperature on the fibers, which weakens the strength of the fibers.更多还原