您的位置:首页  > 论文页面

SiC包覆对SiCnf/SiC复合材料结构和性能的影响

发表时间:2021-09-30  浏览量:116  下载量:13
全部作者: 侯红臣,陈建军,郑旭鹏,程伟强,楼永伟
作者单位: 浙江理工大学材料科学与工程学院
摘 要: 以SiC纳米纤维(SiC nanofiber,SiCnf)气凝胶为增韧材料,通过模压成型工艺制备SiCnf预制体,克服了SiCnf气凝胶难以采用常规方法编织以及机械搅拌易造成损伤的问题。采用前驱体浸渍裂解(precursor infiltration and pyrolysis,PIP)及反应熔渗(reactive melt infiltration,RMI)工艺制备SiCnf增韧SiC陶瓷基复合材料,研究了SiC界面相包覆次数对复合材料结构和性能的影响。结果表明,模压成型制备的预制体中SiCnf完整度好、长径比高,SiCnf体积分数高达19.95%,有效改进了原位生长方式制备的SiCnf含量少、长度短、拔出效应弱的不足。对SiCnf进行2次SiC界面相包覆时,热解产生的SiC不能完全包覆SiCnf,纳米纤维与基体间界面结合强度较高,限制了SiCnf的强韧化效果的发挥;对SiCnf进行4次SiC界面相包覆时,纳米纤维与基体间适宜的界面结合强度使得SiCnf的拔出和裂纹偏转机制得到有效发挥,材料表现为韧性断裂,复合材料抗弯强度及断裂韧性分别达到最大值175.9 MPa和15.4 MPa·m1/2,提升至未包覆SiC界面相复合材料的1.3倍和2.2倍;对SiCnf进行6次SiC界面相包覆时,体系中碳含量仅为7%,限制了材料的致密化。
关 键 词: 无机非金属材料;SiC纳米纤维;界面相;前驱体浸渍裂解;反应熔渗;SiC陶瓷基复合材料
Title: ffect of SiC coating on structure and properties of SiCnf/SiC composites
Author: HOU Hongchen, CHEN Jianjun, ZHENG Xupeng, CHENG Weiqiang, LOU Yongwei
Organization: School of Materials Science & Engineering, Zhejiang Sci-Tech University
Abstract: In the first place, using SiC nanofiber (SiCnf) aerogel as toughening material, the SiCnf preforms were prepared by compression molding, which overcamed the problems that the SiCnf aerogel was difficult to be braided by conventional methods and easily damaged by mechanical stirring. In the second place, the SiCnf-toughened SiC ceramic matrix composites were prepared by precursor infiltration and pyrolysis (PIP) and reactive melt infiltration (RMI). The effect of SiC interfacial phase coating times on the structure and properties of the composites was investigated. The results showed that the integrity and length-diameter ratio of SiCnf in the preforms prepared by compression molding were good, and the volume fraction of SiCnf was as high as 19.95%, the deficiency of SiCnf prepared by in situ growth method with less content, short length and weak pull-out effect was effectively improved. When SiCnf were coated twice with SiC interfacial phase, the pyrolysis SiC could not completely coat the SiCnf, and the interfacial bonding strength between the nanofibers and the matrix was high, which limited the strength and toughening effect of the SiCnf. When SiCnf were coated with SiC interfacial phase for 4 times, the appropriate interfacial bonding strength between the nanofibers and the matrix maked the pull-out and crack deflection mechanisms of the SiCnf play an effective role, and the material belonged ductile fracture. The flexural strength and fracture toughness of the composites reached the maximum values of 175.9 MPa and 15.4 MPa·m1/2, respectively, which were 1.3 times and 2.2 times of those of composites uncoated with SiC interfacial phase. When SiCnf were coated with SiC interfacial phase for 6 times, the carbon content in the system was only 7%, which restricted the densification of the material.
Key words: inorganic nonmetallic materials; SiC nanofibers; interfacial phase; precursor infiltration and pyrolysis; reactive melt infiltration; SiC ceramic matrix composites
发表期数: 2021年9月第3期
引用格式: 侯红臣,陈建军,郑旭鹏,等. SiC包覆对SiCnf/SiC复合材料结构和性能的影响[J]. 中国科技论文在线精品论文,2021,14(3):408-416.
 
0 评论数 0
暂无评论
友情链接