摘要
采用真空热压烧结工艺制备了碳纤维体积分数分别为 2 0 %、4 0 %和 6 0 %的高致密Cf/SiO2 复合材料 ,研究了碳纤维含量对其组织结构、力学性能、热膨胀特性和抗氧化性能的影响规律。结果表明 :SiO2基体及 2 0 %Cf/SiO2 复合材料中 ,SiO2 仍保持非晶态 ,碳纤维含量为 4 0 %和 6 0 %时 ,SiO2 发生部分析晶 ;Cf/SiO2 复合材料的抗弯强度、断裂韧性和断裂应变 ,随碳纤维含量增加均呈现先降低后又增加的趋势 ,而弹性模量则先增后降 ;6 0 %Cf/SiO2 表现出明显伪塑性 ;碳纤维含量增大 ,使复合材料的热膨胀系数成倍增加 。
Highly consensed SiO 2 matrix composites with various volume contents of short carbon fibers (C f), 20%, 40% and 60%, are prepared by vacuum hot pressing. Influence of carbon fiber content on microstructure, mechanical properties, thermal expansion coefficient and thermal oxidation resistance is investigated for the composites.Experimental results indicate that unreinforced SiO 2 matrix and the SiO 2 in its composite with 20% of carbon fibers keep uncrystallized, but the SiO 2 in composites with 40% and 60% of carbon fibers appears to crystallize partially. With increase of carbon fiber content,the bending strength, fracuture toughness and strain would decrease at first and then increase ,but the bending modulus is in the reverse.The composite with 60% of carbon fiber behaves like a pseudoplastic. Thermal expansion coefficient would increase by a few times,and thermal oxidation resistance would degrade with the increase of carbon fiber of composites.
出处
《宇航材料工艺》
CAS
CSCD
北大核心
2001年第4期30-35,共6页
Aerospace Materials & Technology
