Scholarlink

<p>In this study, a C/SiC composite part was fabricated using needle-punched preforms, pyrocarbon interphase deposition, and subsequent SiC densification via chemical vapor infiltration (CVI). Unlike conventional flat-plate rectangular specimen tests, interlaminar shear strength (ILSS) was evaluated using specimens machined directly from the actual composite component, thereby capturing the effects of real processing conditions and geometric constraints. The results demonstrate that Z-directional fiber reinforcements effectively suppress interlaminar slippage, improving shear resistance in the through-thickness direction. In addition, a tailored tearing test method was developed to assess the Z-directional bonding quality of needle-punched preforms, providing a more realistic metric for preform integrity. Combustion testing was conducted to simulate high-temperature operating environments, and ILSS degradation was quantitatively evaluated by extracting shear specimens from post-test components. The optimized preform structure exhibited an improved normalized tearing strength of 2.37 <InlineEquation ID="IEq1"> <EquationSource Format="TEX">\(\pm\)</EquationSource> <EquationSource Format="MATHML"><math> <mo>±</mo> </math></EquationSource> </InlineEquation> 0.11&#xa0;N/mm and achieved an interlaminar shear strength (ILSS) of approximately 44&#xa0;MPa after CVI densification. After combustion exposure, the ILSS exhibited a substantial reduction of approximately 57%, indicating significant interfacial degradation under severe oxidative thermal conditions. Furthermore, microstructural analyses of the SiC coating revealed degradation mechanisms such as erosion and cracking, which are critical to maintaining structural integrity during service. These findings highlight the importance of component-level ILSS evaluation and coating durability assessment for ensuring the reliability of CVI-processed C/SiC composites in high-temperature structural applications.</p> Graphical abstract <p></p>

错误：搜索内容不能为空，请输入英文关键词
错误：关键词超出字数限制，请精简
高级检索

Part-level evaluation of interlaminar shear strength and SiC coating stability in CVI-densified C/SiC composites

  • 期刊论文

  • 发表日期：

    2026年7月8日

查看全文
  • Jungmin Lee

摘要

In this study, a C/SiC composite part was fabricated using needle-punched preforms, pyrocarbon interphase deposition, and subsequent SiC densification via chemical vapor infiltration (CVI). Unlike conventional flat-plate rectangular specimen tests, interlaminar shear strength (ILSS) was evaluated using specimens machined directly from the actual composite component, thereby capturing the effects of real processing conditions and geometric constraints. The results demonstrate that Z-directional fiber reinforcements effectively suppress interlaminar slippage, improving shear resistance in the through-thickness direction. In addition, a tailored tearing test method was developed to assess the Z-directional bonding quality of needle-punched preforms, providing a more realistic metric for preform integrity. Combustion testing was conducted to simulate high-temperature operating environments, and ILSS degradation was quantitatively evaluated by extracting shear specimens from post-test components. The optimized preform structure exhibited an improved normalized tearing strength of 2.37 \(\pm\) ± 0.11 N/mm and achieved an interlaminar shear strength (ILSS) of approximately 44 MPa after CVI densification. After combustion exposure, the ILSS exhibited a substantial reduction of approximately 57%, indicating significant interfacial degradation under severe oxidative thermal conditions. Furthermore, microstructural analyses of the SiC coating revealed degradation mechanisms such as erosion and cracking, which are critical to maintaining structural integrity during service. These findings highlight the importance of component-level ILSS evaluation and coating durability assessment for ensuring the reliability of CVI-processed C/SiC composites in high-temperature structural applications.

Graphical abstract