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人工晶体学报 ›› 2021, Vol. 50 ›› Issue (8): 1525-1533.

• 研究论文 • 上一篇    下一篇

成型压力对SiCnf增韧SiC陶瓷基复合材料微观结构和性能的影响

侯红臣, 郑旭鹏, 楼永伟, 程伟强, 陈建军   

  1. 浙江理工大学材料科学与工程学院,先进陶瓷材料与纤维研究所,杭州 310018
  • 收稿日期:2021-03-05 出版日期:2021-08-15 发布日期:2021-09-14
  • 通讯作者: 陈建军,教授。E-mail:chen@zstu.edu.cn
  • 作者简介:侯红臣(1994—),男,安徽省人,硕士研究生。E-mail:hhc20202020@163.com
  • 基金资助:
    国家自然科学基金(51872262,51572243)

Effect of Molding Pressure on Microstructure and Properties of SiC Nanofiber-Reinforced SiC Ceramic Matrix Composites

HOU Hongchen, ZHENG Xupeng, LOU Yongwei, CHENG Weiqiang, CHEN Jianjun   

  1. Institute of Advanced Ceramic Materials & Fibers, School of Materials Science & Engineering, Zhejiang Sci-Tech University, Hangzhou 310018, China
  • Received:2021-03-05 Online:2021-08-15 Published:2021-09-14

摘要: 研究采用不同成型压力制备不同体积分数的SiC纳米纤维预制体,并通过前驱体浸渍裂解和反应熔渗联用工艺制备了SiC纳米纤维增韧SiC陶瓷基复合材料。研究了成型压力对SiC陶瓷基复合材料结构和性能的影响。结果表明,通过模压成型可实现高体积分数的SiC纳米纤维预制体的制备。当成型压力为40 MPa时,预制体SiC纳米纤维体积分数高达22.13%,但过高的成型压力也会导致SiC纳米纤维断裂。相较于单一前驱体浸渍裂解工艺,采用前驱体浸渍裂解和反应熔渗联用工艺制备的复合材料孔隙率显著降低,材料平均孔隙率从14.19%降至1.43%。当成型压力为30 MPa时,复合材料中游离硅含量低且SiC纳米纤维断裂少,材料抗弯强度和断裂韧性分别达到最大值178 MPa和21.6 MPa·m1/2

关键词: SiC纳米纤维, 成型压力, 前驱体浸渍裂解, 反应熔渗, 碳化硅陶瓷基复合材料

Abstract: SiC nanofibers preforms with different volume fraction of nanofibers were fabricated by the different molding pressures. SiC nanofiber-toughened SiC ceramic matrix composites were prepared by the combined processes of precursor infiltration and pyrolysis with reactive melt infiltration. The effect of molding pressure on the structure and properties of SiC ceramic matrix composites was investigated. Results show that the preforms with high volume fraction of SiC nanofibers can be fabricated by compression molding. When the molding pressure is 40 MPa, the volume fraction of SiC nanofibers is 22.13%. However, there exists the fracture of SiC nanofibers if the molding pressure is too high. The porosity of the composites prepared by the combined processes of precursor infiltration and pyrolysis with reactive melt infiltration is much lower than that by the simple process of precursor infiltration and pyrolysis. The average porosity of the composite materials prepared by these two methods is 1.43% and 14.19%, respectively. When the molding pressure is 30 MPa, the composites have low content of free silicon and the long SiC nanofibers have high length-diameter ratio. Meanwhile, the corresponding value of the bending strength and fracture toughness of the composites is 178 MPa and 21.6 MPa· m1/2, which is the largest under the different molding pressures.

Key words: SiC nanofiber, molding pressure, precursor infiltration and pyrolysis, reactive melt infiltration, silicon carbide ceramic matrix composite

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