Mechanical and thermal properties of silicon-carbide composites fabricated with short Tyranno® Si-Zr-C-O fibre
Mechanical and thermal properties of silicon-carbide composites fabricated with short Tyranno® Si-Zr-C-O fibre
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DOI：
10.1023/a:1017909430037
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发表时间：
2001-08
影响因子：
4.5
通讯作者：
K. Itatani;K. Hattori;D. Harima;M. Aizawa;I. Okada;I. Davies;H. Suemasu;A. Nozue
中科院分区：
文献类型：
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作者：
K. Itatani;K. Hattori;D. Harima;M. Aizawa;I. Okada;I. Davies;H. Suemasu;A. Nozue
采用热压技术制备了碳化硅 (SiC) 复合材料，其中含有 10–50 质量%（10.5–51.2 体积%）的 Tyranno® Si-Zr-C-O 短纤维（平均长度~0.5 mm）和 0–10 摩尔% 的 Al4C3 作为烧结助剂。首先，固定Al4C3含量为5 mol%，考察Si-Zr-C-O纤维的添加对1800 ℃热压30 min SiC复合材料相对密度（堆积密度/真密度）的影响。尽管添加 10 质量％的 Si-Zr-C-O 时，相对密度降低至 87.4％，但进一步增加 Si-Zr-C-O 纤维的量，在添加 40 质量％的纤维时，密度增加至最大 92.8％。其次，通过将Si-Zr-C-O纤维的量固定为40质量%，研究了改变Al4C3添加量对相对密度的影响。制备致密 SiC 复合材料的最佳 Al4C3 添加量为 5 mol%。添加20~40质量%Si-Zr-C-O纤维（Al4C3用量为5 mol%）的热压SiC复合材料的断裂韧性为3.2~3.4 MPa·m1/2，比未添加Si-Zr-C-O纤维的热压SiC复合材料的断裂韧性（2.39 MPa·m1/2）提高约1.5倍。 SEM 观察显示 Si-Zr-C-O 纤维在断裂表面脱粘和拔出的证据。添加 5 mol% Al4C3 和 40 质量% Si-Zr-C-O 纤维的热压 SiC 复合材料由于在暴露表面及其附近形成了 SiO2 层，因此在空气中 1300 °C 下表现出优异的耐热性。
Silicon carbide (SiC) composites reinforced with 10–50 mass% (10.5–51.2 vol%) of short Tyranno® Si-Zr-C-O fibre (average length ∼0.5 mm) and 0–10 mol% of Al4C3as a sintering aid were fabricated using the hot-pressing technique. Firstly, the effect of Si-Zr-C-O fibre addition on the relative density (bulk density/true density) of the SiC composite hot-pressed at 1800 °C for 30 min was examined by fixing the amount of Al4C3to be 5 mol%. Although the relative density was reduced to 87.4% for 10 mass% of Si-Zr-C-O addition, further increases in the amount of Si-Zr-C-O fibre increased density to a maximum of 92.8% at 40 mass% of fibre addition. Secondly, the effect of varying the amount of Al4C3addition on the relative density was examined by fixing the amount of Si-Zr-C-O fibre to be 40 mass%. The optimum amount of Al4C3addition for the fabrication of dense SiC composite was found to be 5 mol%. The fracture toughness of the hot-pressed SiC composites with 20–40 mass% of Si-Zr-C-O fibre addition (amount of Al4C3: 5 mol%) was 3.2–3.4 MPa · m1/2and approximately 1.5 times higher than that (2.39 MPa · m1/2) of the hot-pressed SiC composite with no Si-Zr-C-O fibre addition. SEM observation showed evidence of Si-Zr-C-O fibre debonding and pull-out at the fracture surfaces. The hot-pressed SiC composite with 5 mol% of Al4C3and 40 mass% of Si-Zr-C-O fibre additions showed excellent heat-resistance at 1300 °C in air due to the formation of a SiO2layer at and near exposed surfaces.