摘要
以SiC粉末、醇溶性酚醛树脂粉末以及炭纤维毡、炭纤维无纬布为原料,采用料浆刷涂-针刺-温压固化-高温碳化工艺,在料浆中酚醛树脂的体积分数分别为10%和15%、温压固化压力分别为8 MPa和20 MPa条件下制备C_(f)/SiC多孔预制体,然后通过化学气相渗透法沉积SiC,快速制备C_(f)/SiC陶瓷基复合材料。观察和分析复合材料的形貌和组织结构,测定材料的密度、孔隙率、抗弯强度和断裂韧性等性能。结果表明:料浆中的酚醛树脂体积分数较低时,C_(f)/SiC复合材料的性能较好,并且随固化压力增加而提高。在酚醛树脂体积分数为10%、温压固化压力为20 MPa条件下得到开孔隙率为13.1%的高致密C_(f)/SiC复合材料,该材料的基体较致密,且纤维束和基体之间基本没有孔隙;当材料受到外加载荷时,通过纤维拔出、纤维脱粘和裂纹偏转来提高复合材料的强度和韧性,断裂方式为假塑性断裂,抗弯强度和断裂韧性都较高,分别为570 MPa和18.6 MPa·m^(1/2)。
C_(f)/SiC ceramic matrix composites were prepared byslurry brushing-needle punching-warm pressure curinghigh temperature carbonization proces using SiC powders,alcohol-soluble phenolic resin powders,carbon fiber felt and carbon fibers weft free cloth as raw materials.The C_(f)/SiC porous preform was prepared by slurry brush coating,puncture,temperature pressure curing and high temperature carbonization.The volume fraction of phenolic resin in the slurry was respectively 10%and 15%,and temperature and pressure curing pressures was 8 MPa and 20 MPa,respectively.And then SiC was deposited by chemical vapor infiltration method to quickly prepare C_(f)/SiC ceramic matrix composites.The morphology and microstructure of the materials were observed and analyzed.The properties such as density,porosity,bending strength and fracture toughness of the materials were measured.The results show that the properties of C_(f)/SiC composites are better when the volume fraction of phenolic resin in the slurry is low,and the properties increase with the increase of curing pressure.When the volume fraction of phenolic resin was 10%and the curing pressure was 20 MPa,a high density C_(f)/SiC composite with open porosity of 13.1%is obtained.The matrix of C_(f)/SiC composite was relatively compact,and there was almost no pores between the fiber bundles and the matrix.When the composite was subjected to the applied load,the strength and toughness of the composite were improved by fiber pulling out,fiber debonding and crack deflection.The fracture mode of the composite was pseudoplastic fracture,with the highest bending strength and fracture toughness of 570 MPa and 18.6 MPa·m^(1/2),respectively.
作者
王洋
李国栋
于士杰
姜毅
WANG Yang;LI Guodong;YU Shijie;JIANG Yi(State Key Laboratory of Powder Metallurgy,Central South University,Changsha 410083,China)
出处
《粉末冶金材料科学与工程》
2022年第1期92-101,共10页
Materials Science and Engineering of Powder Metallurgy
基金
轻质高强结构材料国家重点实验室基金资助项目。
