摘要
采用CVI+PIC工艺制备了四种碳毡增强碳基复合材料(C/C),其中对三种样品A、B、C在2 500℃进行了一次石墨化处理,样品D未进行石墨化处理.为与900℃碳化对比,研究了1 500℃碳化对复合材料微观结构及热性能的影响.结果表明:碳化温度由900℃提高到1 500℃后,样品A的开孔率下降11.6%～13.5%,1 000℃的xy向线膨胀系数由1.75×10-6/K增大到2.17×10-6/K;xy向和z向的800℃热导率分别由65.07 W/(m·K)、45.98 W/(m·K)增大到75.44 W/(m·K)、54.86W/(m·K);xy向和z向的比热容分别由1.70 kJ/(kg·K)、1.43 kJ/(kg·K)增大到1.79 kJ/(kg·K)、2.19 kJ/(kg·K).样品B和样品C也表现出基本相同的趋势;随着碳化温度由900℃提高到1 500℃,样品D中微晶尺寸由2 nm增大到4nm.
Four kinds of carbon felt reinforced carbon matrix composites (C/C) are prepared by CVI and PIC, with three kinds (sample A, B, and C) graphitized once during PIC process at 2 500℃, and microstructure and thermal properties of them are characterized . The results show, when the carbonization temperature rises from 900 ~ 1 500℃, the void volume of sample A drops by 11.6%～13.5%, and its linear expansion coefficient of xy direction at 1 000℃ rises from 1.75 ×10 -6~ 2.17×10 -6/K, and its thermal conductivity of xy and z direction at 800℃ correspondently rise from 65.07 ~ 75.44 W/(m·K), 45.98~ 54.86 W/(m·K), and its specific thermal capacity of xy and z direction at 800℃ correspondently rises from 1.70~ 1.79 kJ/(kg·K), 1.43 ~ 2.19 kJ/(kg·K), and sample B and sample C act similarly. The crystal size of ungraphitized sample D grows from 2~ 4 nm, when the carbonization temperature rises from 900~ 1 500℃.
出处
《宇航材料工艺》
CAS
CSCD
北大核心
2005年第2期47-51,共5页
Aerospace Materials & Technology
