Scholarlink

<p>Carbon fiber–reinforced silicon nitride (C<sub>f</sub>/Si<sub>3</sub>N<sub>4</sub>) composites were fabricated by spark plasma sintering (SPS) using α-, β-, and γ-Si<sub>3</sub>N<sub>4</sub> powders to clarify the influence of the initial Si<sub>3</sub>N<sub>4</sub> phase on microstructural evolution and functional properties. The results show that the starting phase significantly affects densification behavior, phase transformation, and mechanical and tribological performance. The composite derived from α-Si<sub>3</sub>N<sub>4</sub> achieved the highest relative density (96.53%) and exhibited an optimal balance of fracture toughness (10.87&#xa0;MPa m<sup>0.5</sup>), thermal conductivity (66 W/m K), and stable friction behavior (COF ≈ 0.46). This performance is attributed to the in-situ formation of a self-reinforced β-Si<sub>3</sub>N<sub>4</sub> microstructure during the α → β phase transformation, which promotes crack deflection, crack bridging, and effective load transfer in synergy with carbon fibers. In contrast, β- and γ-Si<sub>3</sub>N<sub>4</sub>–based composites showed lower densification or excessive hardness associated with increased porosity and secondary phase formation. These findings demonstrate that controlling the initial Si<sub>3</sub>N<sub>4</sub> phase provides an effective microstructural design strategy for developing high-performance C<sub>f</sub>/Si<sub>3</sub>N<sub>4</sub> composites for thermostructural applications such as aerospace brake discs.</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

Concurrent optimization of fracture toughness, thermal conductivity, and tribological behavior in Cf/Si3N4 composites via phase driven selection

  • 期刊论文

  • 出版模式：

    开放获取

  • 发表日期：

    2026年3月28日

查看全文
  • Saeed Hoseinzadeh,
  • Mohammad Reza Loghman Estarki,
  • Ali Ghasemi,
  • Saeed Zahabi,
  • Gholamreza Gordani,
  • Ehsan Mohammad Sharifi

摘要

Carbon fiber–reinforced silicon nitride (Cf/Si3N4) composites were fabricated by spark plasma sintering (SPS) using α-, β-, and γ-Si3N4 powders to clarify the influence of the initial Si3N4 phase on microstructural evolution and functional properties. The results show that the starting phase significantly affects densification behavior, phase transformation, and mechanical and tribological performance. The composite derived from α-Si3N4 achieved the highest relative density (96.53%) and exhibited an optimal balance of fracture toughness (10.87 MPa m0.5), thermal conductivity (66 W/m K), and stable friction behavior (COF ≈ 0.46). This performance is attributed to the in-situ formation of a self-reinforced β-Si3N4 microstructure during the α → β phase transformation, which promotes crack deflection, crack bridging, and effective load transfer in synergy with carbon fibers. In contrast, β- and γ-Si3N4–based composites showed lower densification or excessive hardness associated with increased porosity and secondary phase formation. These findings demonstrate that controlling the initial Si3N4 phase provides an effective microstructural design strategy for developing high-performance Cf/Si3N4 composites for thermostructural applications such as aerospace brake discs.