采用化学气相渗积工艺制备出密度分别为0.81,1.10,1.26,1.52 g/cm3的C/C复合材料坯体,再以聚碳硅烷(PCS)为先驱体,通过先驱体转化法制备出密度相近的C/C-SiC复合材料,并对它们的弯曲强度和抗氧化性能作了对比分析.结果表明:由密度为0.81 g/cm3的C/C复合材料坯体制得的C/C-SiC复合材料具有最高的弯曲强度,达265 MPa,具有最好的抗氧化性能,在1 000℃氧化2h后失重率为2.61％.

选用聚碳硅烷(PCS)为前驱体,分别将3D编织和2.5D编织的C/C复合材料,由初始密度1.32 g/cm3制备成密度为1.70g/cm3的C/C-SiC复合材料,测试了它们的弯曲强度和抗氧化性能,并分析了微观结构.实验表明:3D编织的C/C-SiC复合材料具有更高的平均弯曲强度,达到226.1 MPa;两种C/C-SiC复合材料均具有相当优异的抗氧化性,1 000℃下,2h最大氧化失重率不到5％,但2.5D编织的C/C-SiC复合材料抗氧化性能更优异.

According to the theory of accessing and expressing the uncertainty,the measurement uncertainty of FS4270 fluorosilicone rubber Shore-A hardness was attained.It was found that the thickness,surface,testing time,accuracy of the measuring instrument and temperature affected the accuracy of the result.Therefore we should carry out the experiment strictly according to the standards