径棒法编织C/C复合材料热膨胀性能

Thermal expansion property of C/C composites woven with radial carbon rods

热膨胀系数是表征C/C复合材料热稳定性的关键性能参数。为了解材料的热膨胀行为,以径棒法编织C/C复合材料为实验材料,分析了该材料的热膨胀性能。结果表明,径棒法编织C/C复合材料热膨胀性能呈现明显各向异性特征,径向方向材料的热膨胀系数最大。随着温度升高,材料热膨胀系数呈现增大趋势,800～1 000℃热膨胀性能趋于稳定。在本次实验中,材料密度由1.89 g/cm3提高至1.96 g/cm3,热膨胀系数增大。对完成致密的样品进行900℃热处理,材料1 000℃下径向热膨胀系数由热处理前的8.486×10-6℃-1降低至3.488×10-6℃-1。

The thermal expansion coefficient is the key parameter related to the thermal stability of C/C composite.The thermal expansion performance characteristics of radial rod preform composite were analyzed in order to understand the linear expansion behavior of C/C composite.Results show that the thermal expansion properties of the radial rod preform composite present significant anisotropic character,and the radial expansion coefficient is the highest.The thermal expansion coefficient increases with the increase of temperature,and it is stable between 800 ℃ and 1 000 ℃.The thermal expansion coefficient of this material increases when the density increases from 1.89 g/cm^3 to 1.96 g/cm^3.The radial expansion coefficient of this material at 1 000 ℃ decreases from 8.486×10^-6 ℃^-1 to 3.488×10^-6 ℃^-1 after the heat treatment at 900 ℃.