Scholarlink

Abstract <p>The structure and properties of the (ZrB<sub>2</sub>–TiB<sub>2</sub>–SiC)–(<i>h</i>-BN) ceramic composites are studied. In the (ZrB<sub>2</sub>–TiB<sub>2</sub>–SiC)–(<i>h</i>-BN) system, the (Zr<sub>0.83</sub>Ti<sub>0.17</sub>)B<sub>2</sub> substitutional solid solution is formed during sintering. The addition of low-modulus hexagonal boron nitride (<i>h</i>-BN) inclusions increases the fracture toughness (<i>K</i><sub>IC</sub>) and the ultimate flexural strength (σ<sub><i>f</i></sub>). The highest values of <i>K</i><sub>IC</sub> = 6.01 ± 0.09 MPa m<sup>1/2</sup> and σ<sub><i>f</i></sub> = 544 ± 8 MPa of the (ZrB<sub>2</sub>–TiB<sub>2</sub>–SiC)–(<i>h</i>-BN) ceramic composites are achieved with the addition of 5 vol % of <i>h</i>-BN. The addition of low-modulus <i>h</i>-BN inclusions into a high-modulus ceramic (ZrB<sub>2</sub>–TiB<sub>2</sub>–SiC) matrix ensured the dissipation of crack energy at relatively weak internal “matrix–inclusion” boundaries due to crack bifurcation (the Cook–Gordon mechanism). In the (ZrB<sub>2</sub>–TiB<sub>2</sub>–SiC)–(<i>h</i>-BN) system, a noticeable increase in <i>K</i><sub>IC</sub> of the composites being studied is due to the action of two mechanisms: the Cook–Gordon mechanism and the stopping of cracks in the field of residual compressive stresses. It is found that as the volume content of <i>h</i>-BN increases, the contribution of the Cook–Gordon mechanism to the fracture toughness of the (ZrB<sub>2</sub>–TiB<sub>2</sub>–SiC)–(<i>h</i>-BN) ceramic composites increases. However, a further increase in the <i>h</i>‑BN content (over 5 vol %) leads to a significant decrease in the fracture toughness of the (ZrB<sub>2</sub>–TiB<sub>2</sub>–SiC)–(<i>h</i>-BN) ceramic composites.</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

Fracture Toughness of Ceramic Composites Based on ZrB2, TiB2, and SiC with Low-Modulus h-BN Inclusions

  • 期刊论文

  • 发表日期：

    2026年4月26日

查看全文
  • M. P. Lukyanets,
  • A. S. Buyakov,
  • I. A. Fotin,
  • V. V. Shmakov,
  • E. V. Abdulmenova,
  • M. A. Rudmin,
  • S. P. Buyakova

摘要

Abstract

The structure and properties of the (ZrB2–TiB2–SiC)–(h-BN) ceramic composites are studied. In the (ZrB2–TiB2–SiC)–(h-BN) system, the (Zr0.83Ti0.17)B2 substitutional solid solution is formed during sintering. The addition of low-modulus hexagonal boron nitride (h-BN) inclusions increases the fracture toughness (KIC) and the ultimate flexural strength (σf). The highest values of KIC = 6.01 ± 0.09 MPa m1/2 and σf = 544 ± 8 MPa of the (ZrB2–TiB2–SiC)–(h-BN) ceramic composites are achieved with the addition of 5 vol % of h-BN. The addition of low-modulus h-BN inclusions into a high-modulus ceramic (ZrB2–TiB2–SiC) matrix ensured the dissipation of crack energy at relatively weak internal “matrix–inclusion” boundaries due to crack bifurcation (the Cook–Gordon mechanism). In the (ZrB2–TiB2–SiC)–(h-BN) system, a noticeable increase in KIC of the composites being studied is due to the action of two mechanisms: the Cook–Gordon mechanism and the stopping of cracks in the field of residual compressive stresses. It is found that as the volume content of h-BN increases, the contribution of the Cook–Gordon mechanism to the fracture toughness of the (ZrB2–TiB2–SiC)–(h-BN) ceramic composites increases. However, a further increase in the h‑BN content (over 5 vol %) leads to a significant decrease in the fracture toughness of the (ZrB2–TiB2–SiC)–(h-BN) ceramic composites.