无机材料学报 ›› 2023, Vol. 38 ›› Issue (10): 1163-1168.DOI: 10.15541/jim20230126 CSTR: 32189.14.10.15541/jim20230126

所属专题: 【结构材料】超高温结构陶瓷(202409)

• 研究论文 • 上一篇    下一篇

大厚度SiC素坯的脱脂分析及其无压高致密制备

黄毅华1(), 黄政仁1, 沙闻浩1,2, 周雅斌1, 谭周茜1,2, 张明康1   

  1. 1.中国科学院 上海硅酸盐研究所, 高性能陶瓷与超微结构国家重点实验室, 上海 200050
    2.中国科学院大学 材料科学与光电技术学院, 北京 100049
  • 收稿日期:2023-03-10 修回日期:2023-05-18 出版日期:2023-10-20 网络出版日期:2023-05-24
  • 作者简介:黄毅华(1982-), 男, 研究员. E-mail: wyu@mail.sic.ac.cn
  • 基金资助:
    国家重点研发计划(2022YFB3706200)

Thick SiC Green Bodies: Degreasing Analysis and Pressureless High Density Sintering

HUANG Yihua1(), HUANG Zhengren1, SHA Wenhao1,2, ZHOU Yabin1, TAN Zhouxi1,2, ZHANG Mingkang1   

  1. 1. State Key Laboratory of High-Performance Ceramics and Ultrastructure, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050, China
    2. College of Materials Science and Opto-Electronic Technology, University of Chinese Academy of Sciences, Beijing 100049, China
  • Received:2023-03-10 Revised:2023-05-18 Published:2023-10-20 Online:2023-05-24
  • About author:HUANG Yihua (1982-), male, professor. E-mail: wyu@mail.sic.ac.cn
  • Supported by:
    National Key Research and Development Program of China(2022YFB3706200)

摘要:

高致密的大厚度SiC陶瓷在装甲防护领域具有显著优势, 但是制备厚度100 mm以上的块体SiC陶瓷具有极大的挑战性。针对大厚度SiC陶瓷烧结易开裂、不致密等问题, 本工作着重对大厚度SiC素坯的脱脂产物、压力-不完全脱脂分析等开展了研究。采用TG-MS分析了大厚度陶瓷脱脂过程中的酚醛树脂裂解残余, 其中甲醛等小分子裂解物易脱除, 而二甲基苯酚等高分子产物易滞留芯部, 导致大厚度陶瓷的烧结不致密。经脱脂优化, 素坯表层-芯部密度一致, 均在1.81~1.84 g/cm3范围。经2150 ℃烧结后, 得到不开裂、不变形的大厚度SiC陶瓷, 块体陶瓷表层与芯部的密度均达到3.14 g/cm3。大厚度陶瓷表层与芯部微观结构相似, 表层抗弯强度为(433±48) MPa、芯部抗弯强度达到(411±84) MPa。经分析认为, 大厚度陶瓷芯部不完全脱脂是导致开裂和不致密的主要原因。

关键词: 大厚度, SiC陶瓷, 脱脂分析, 不完全脱脂

Abstract:

SiC ceramics with high thickness and high density are highly advantageous for armor protection, but it is difficult to produce bulk SiC ceramics with thicknesses more than 100 mm. This work was concentrated on the problems of easy cracking and non-densification in the thick SiC ceramic sintering, and degreasing products as well as pressure-incomplete degreasing process were investigated. In order to degrease thick ceramics, phenolic resin’s pyrolysis residue was examined using TG-MS. Formaldehyde and other small-molecule byproducts of breakdown were quickly eliminated, but macromolecule byproducts like dimethylphenol were easily retained in the core, leading to the noncompact sintering of thick ceramics. After degreasing optimization, the blank’s surface-core density is almost constant, ranging from 1.81 to 1.84 g/cm3. In contrast, the test group shows no cracking or deformation after sintering at 2150 ℃, and both surface and core of the large thickness ceramics obtain a density up to 3.14 g/cm3 with similar microstructure. The fracture strength of the core is (411±84) MPa, while the fracture strength of the surface is (433±48) MPa. According to the investigation, the ceramic core’s insufficient degreasing is the primary reason for the cracking and poor density.

Key words: large thickness, SiC ceramics, degreasing effect analysis, insufficient degreasing

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