CVD PyC对炭泡沫结构及性能的影响

Microstructure and Properties of Carbon Foams Reinforced by CVD PyC

以AR中间相沥青为原料,采用中间相沥青自发泡法在发泡压力为0.1、3.0MPa,发泡温度为450℃的条件下制备了两种不同体积密度的炭泡沫CF-1和CF-2.将CF-1经过10h和70h化学气相沉积热解炭(CVD PyC)处理后得到炭泡沫CF-1-PC1和CF-1-PC2.测定了炭泡沫的抗压强度和导热系数,利用SEM和光学显微镜观察了炭泡沫的孔结构,考察了CVD PyC对炭泡沫结构及性能的影响.研究结果表明,CVD PyC处理可以增加炭泡沫韧带宽度,封填孔壁微裂纹;沥青炭和热解炭之间无明显界面,结合良好;经过CVD PyC处理后得到的CF-1-PC1和CF-1-PC2的体积密度、抗压强度、导热系数分别为:0.196g·cm^(-3)、1.89MPa、0.314W·m^(-1)·K^(-1)和0.461g·cm(-3)、11.93MPa、1.581W·m^(-1)·K^(-1).

Two carbon foams with different bulk density,marked as CF-1 and CF-2 were prepared from AR mesophase pitch by self-foaming method at 450℃under different foaming pressures,0.1MPa and 3MPa,respectively.Then CF-1 was reinforced by chemical vapor deposition（CVD）PyC for 10h and 70h,getting two carbon foams marked as CF-1-PC1 and CF-1-PC2.The pore structures of four carbon foams were characterized by scanning electron microscope（SEM）and optical microscope（OM）,and compressive strength and thermal conductivity were measured in further.The influences of CVD PyC process on carbon foams were investigated.The results show that CVD PyC can widen the ligament of carbon foams and close cracks in pore walls,No obvious interface exists between pitch carbon and PyC. The corresponding bulk density,compressive strength and thermal conductivity of CF-1-PC1 and CF- 1-PC2 are 0.196g·cm（-3）,1.89MPa,0.314W·m（-1）·K（-1）and 0.461g·cm（-3）,11.93MPa,1.581W·m（-1）·K（-1）, respectively.