Scholarlink

<p>High-temperature-resistant needled C/SiC composites are critical for aerospace applications, but their mechanical properties and failure mechanisms at elevated temperatures remain insufficiently explored. This study aims to optimize the needling process parameters for spreading carbon fiber fabric/web needled felts to enhance their mechanical performance and understand their high-temperature behavior. Various needling parameters, including needling density (25–40 needles/cm²), depth (11 and 15&#xa0;mm), and needle hook type (F and G), were tested. The microstructure and mechanical properties of the felts were characterized by Micro-CT, tensile, and interlaminar peel tests. On this basis, the NP-M15G felt (needling density 30–35 needles/cm², needling depth 15&#xa0;mm, G-type hook needle) was selected as the preform to fabricate needled C/SiC composites via the polymer infiltration and pyrolysis (PIP) process, followed by three-point bending tests at room temperature and 1600&#xa0;°C. The results show that the felt compactness, tensile strength, and interlaminar peel strength first increase and then decrease with increasing needling density. Increasing the needling depth promotes the formation of longer needled fiber bundles and improves structural compactness, thereby enhancing the overall mechanical performance. In addition, the G-type needle introduces more Z-direction fiber bundles, further improving interlaminar properties. The NP-M15Gs composite exhibits non-brittle fracture behavior at both room temperature and 1600&#xa0;°C; however, the flexural strength and modulus decrease by approximately 32.49% and 51.40% at high temperature, respectively. This degradation is mainly attributed to matrix softening, weakened interfacial bonding, and the combined effects of activated creep and thermal-mismatch stresses, which intensify interfacial sliding, fiber debonding, and delamination.</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

High-Temperature Mechanical Properties and Damage Mechanisms of Spreading Carbon Fiber Fabric/Web Needled Felt Composites

  • 期刊论文

  • 发表日期：

    2026年8月4日

查看全文
  • Xiaomeng Wang,
  • Zhongwei Fang,
  • Yusen Wang,
  • Shun Chen,
  • Junjie Xu,
  • Ling Wang,
  • Haipeng Qiu,
  • Diantang Zhang

摘要

High-temperature-resistant needled C/SiC composites are critical for aerospace applications, but their mechanical properties and failure mechanisms at elevated temperatures remain insufficiently explored. This study aims to optimize the needling process parameters for spreading carbon fiber fabric/web needled felts to enhance their mechanical performance and understand their high-temperature behavior. Various needling parameters, including needling density (25–40 needles/cm²), depth (11 and 15 mm), and needle hook type (F and G), were tested. The microstructure and mechanical properties of the felts were characterized by Micro-CT, tensile, and interlaminar peel tests. On this basis, the NP-M15G felt (needling density 30–35 needles/cm², needling depth 15 mm, G-type hook needle) was selected as the preform to fabricate needled C/SiC composites via the polymer infiltration and pyrolysis (PIP) process, followed by three-point bending tests at room temperature and 1600 °C. The results show that the felt compactness, tensile strength, and interlaminar peel strength first increase and then decrease with increasing needling density. Increasing the needling depth promotes the formation of longer needled fiber bundles and improves structural compactness, thereby enhancing the overall mechanical performance. In addition, the G-type needle introduces more Z-direction fiber bundles, further improving interlaminar properties. The NP-M15Gs composite exhibits non-brittle fracture behavior at both room temperature and 1600 °C; however, the flexural strength and modulus decrease by approximately 32.49% and 51.40% at high temperature, respectively. This degradation is mainly attributed to matrix softening, weakened interfacial bonding, and the combined effects of activated creep and thermal-mismatch stresses, which intensify interfacial sliding, fiber debonding, and delamination.