无机材料学报 ›› 2023, Vol. 38 ›› Issue (5): 569-576.DOI: 10.15541/jim20220548 CSTR: 32189.14.10.15541/jim20220548

• 研究论文 • 上一篇    下一篇

高温热处理对国产KD-SA型SiC纤维组成结构与力学性能的影响

吴爽(), 苟燕子(), 王永寿, 宋曲之, 张庆雨, 王应德()   

  1. 国防科技大学 空天科学学院, 新型陶瓷纤维与及其复合材料重点实验室, 长沙 410073
  • 收稿日期:2022-09-19 修回日期:2022-11-10 出版日期:2022-11-16 网络出版日期:2022-11-16
  • 通讯作者: 苟燕子, 副研究员. E-mail: y.gou2012@hotmail.com;
    王应德, 教授. E-mail: wangyingde@nudt.edu.cn
  • 作者简介:吴 爽(1996-), 女, 博士研究生. E-mail: alanwu37@163.com
  • 基金资助:
    国家自然科学基金(51772327);湖南省自然科学基金面上项目(2022JJ30662);科工局稳定支持科研项目(WDZC20205500504);科工局稳定支持科研项目(WDZC20215250507)

Effect of Heat Treatment on Composition, Microstructure and Mechanical Property of Domestic KD-SA SiC Fibers

WU Shuang(), GOU Yanzi(), WANG Yongshou, SONG Quzhi, ZHANG Qingyu, WANG Yingde()   

  1. Science and Technology on Advanced Ceramic Fibers and Composites Laboratory, College of Aerospace Science and Engineering, National University of Defense Technology, Changsha 410073, China
  • Received:2022-09-19 Revised:2022-11-10 Published:2022-11-16 Online:2022-11-16
  • Contact: GOU Yanzi, associate professor. E-mail: y.gou2012@hotmail.com;
    WANG Yingde, professor. E-mail: wangyingde@nudt.edu.cn
  • About author:WU Shuang(1996-), female, PhD candidate. E-mail: alanwu37@163.com
  • Supported by:
    National Natural Science Foundation of China(51772327);Natural Science Foundation of Hunan Province(2022JJ30662);Fund of Industry for National Defence(WDZC20205500504);Fund of Industry for National Defence(WDZC20215250507)

摘要:

高结晶近化学计量比SA型SiC纤维以其优异的耐温性, 在新一代航空发动机和高超声速飞行器等领域得到广泛应用。对比国产第二代SiC纤维(F-II), 本工作研究了第三代SA型SiC纤维(F-III)高温热处理前后的微观结构演变和拉伸强度及断裂行为。结果表明, F-III纤维主要由β-SiC晶粒(~200 nm)和少量游离碳组成, F-II纤维则由β-SiC晶粒(~5 nm)、游离碳和SiCxOy无定形相组成。与F-II纤维相比, F-III纤维具有更大的晶粒尺寸与孔隙, 室温下的拉伸强度较低。但经1800 ℃热处理后, F-III纤维结构和强度基本保持不变, 而F-II纤维由于发生了SiCxOy相的分解和晶粒长大, 强度明显降低。SA型SiC纤维的耐高温性能优异, 可归因于纤维组成结构上的高结晶、大晶粒和低碳氧含量。

关键词: SiC纤维, 高温热处理, 微观结构, 拉伸强度

Abstract:

Polycrystalline near stoichiometric SA type SiC fibers have a prospective application in the fields of the new generation aero engine and hypersonic vehicles due to their excellent temperature resistance. In this work, microstructure evolution, tensile strength as well as fracture behavior of the second-generation domestic F-II SiC and the third-generation SA (F-III) SiC fibers before and after heat treatment were studied. The results showed that F-III fiber was mainly composed of β-SiC grains (~200 nm) and a small amount of free carbon, while F-II fiber was composed of β-SiC grains (~5 nm), free carbon and amorphous SiCxOy phase. Compared with the F-II fiber, the F-III fiber showed lower tensile strength at room temperature, owing to their larger grain size and pores. However, after heat treatment at 1800 ℃, the structure and strength of F-III fiber remained almost unchanged, while the strength of F-II fiber decreased sharply due to decomposition of SiCxOy phase and grain growth. The excellent high temperature resistance of SA type fiber could be attributed to high crystallinity, large grain size, low carbon and oxygen content in microstructure and composition.

Key words: SiC fibers, heat treatment, microstructure, tensile strength

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