摘要
碳/碳复合材料以其优异的性能广泛应用于航空航天、装备等领域,但碳纤维预制体成本高等因素限制了碳/碳复合材料的发展。碳泡沫具有三维网状结构,其韧带表现出与碳纤维相似的性质,可以作为增强相制备新型碳/碳复合材料。本文以酚醛树脂作为碳源,NaCl作为造孔剂,制备出不同碳纤维体积含量(0vol%、1vol%、3vol%、5vol%、7vol%)的碳泡沫作为碳/碳复合材料预制体,利用热梯度化学气相渗积(TGCVI)快速致密化技术制备碳/碳复合材料,考察了碳纤维含量对碳纤维/碳泡沫预制体及其致密化后密度、微观结构和力学性能的影响。结果表明:随着碳纤维含量的增加,碳纤维/碳泡沫预制体中的微裂纹数量明显增加,密度由0.51 g/cm^(3)逐渐降低至0.31 g/cm^(3),抗压强度由51.33 MPa下降至1.35 MPa,抗弯强度由42.53 MPa下降至6.32 MPa。致密化之后碳/碳复合材料抗压强度与抗弯强度显著提升,最高分别为183.67 MPa和123.46 MPa,其密度为1.09 g/cm^(3),因此具有高比强度。致密化后复合材料的热导率从0.298 W/(m·K)(致密化前)增大到2.484 W/(m·K),提升了734%,这是由于致密化后碳纤维与热解碳形成了三维导热网络。
Carbon/carbon composites has been widely used in aerospace,weaponry and other fields with their excellent properties.However,the development of carbon/carbon composites has been limited by the high cost of carbon fiber preforms.Carbon foam has a three-dimensional network structure,and its ligaments show similar properties to carbon fibers,which can be used as the reinforcing phase to prepare carbon/carbon composites.In this paper,carbon foams with different carbon fiber volume contents(0vol%,1vol%,3vol%,5vol%,7vol%)were prepared as carbon/carbon composites preforms by using phenolic resin as the carbon source and NaCl as the pore-forming agent,and the carbon/carbon composites were prepared by using the rapid densification technique of thermal gradient chemical vapour infiltration(TG-CVI),which investigated the effects of carbon fiber content on the carbon fiber/carbon foam preform and its density,microstructure and mechanical properties after densification.The effects of carbon fiber content on the density,microstructure and mechanical properties of the carbon fiber/carbon foam preform and its densification were investigated.The results showed that with the increase of carbon fiber content,the number of microcracks in the carbon fiber/carbon foam precast body increased significantly,the density gradually decreased from 0.51 g/cm^(3)to 0.31 g/cm^(3),and the compressive strength decreased from 51.33 MPa to 1.35 MPa,flexural strength decreased from 42.53 MPa to 6.32 MPa.The compressive and flexural strengths of the carbon/carbon composites were significantly increased after densification,up to 183.67 MPa and 123.46 MPa,respectively,while the density was 1.09 g/cm^(3),resulting in high specific strength.The thermal conductivity of the composites increased from 0.298 W/(m·K)(before densification)to 2.484 W/(m·K),an increase of 734%,which was attributed to the formation of a three-dimensional thermal conductivity network between the carbon fibers and pyrolytic carbon after densification.
作者
王兴俊
贾建刚
潘子康
刘第强
臧树俊
WANG Xingjun;JIA Jiangang;PAN Zikang;LIU Diqiang;ZANG Shujun(School of Materials Science and Engineering,Lanzhou University of Technology,Lanzhou 730050,China;State Key Laboratory of Advanced Processing and Recycling of Non-ferrous Metals,Lanzhou University of Technology,Lanzhou 730050,China;Harbin Boiler Plant CO.,LTD.,Harbin 150046,China)
出处
《复合材料学报》
EI
CAS
CSCD
北大核心
2024年第8期4180-4188,共9页
Acta Materiae Compositae Sinica
基金
国家自然科学基金(52162005)
甘肃省青年科技基金(23JRRA777)。
关键词
C/C复合材料
酚醛树脂
碳纤维
碳泡沫
化学气相增密
力学性能
C/C composites
phenolic resins
carbon fiber
carbon foam
chemical vapour phase densification
mechanical properties
