Abstract In this paper, the dense SiC/SiBCN(O) nanocomposite without obvious crack and/or void was prepared by employing SiBCN(O) amorphous ceramics as starting material. Via controlling heat treatment time of the raw material at 1400 °C, nano β-SiC grains were in situ generated and uniformly dispersed within the amorphous SiBCN(O) ceramic matrix, and the target materials were thus obtained, which may provide a new strategy for fabricating the dense SiBCN(O) based nanocomposties. The influence of dwelling time on chemical composition, grain precipitation and mechanical properties of the materials were also investigated. The experimental results showed that the prepared SiC/SiBCN(O) nanocomposite was dense and pore/crack free, and with the increase in holding time at 1400 °C, the chemical composition of the materials became more uniform and its mechanical properties were significantly improved as well. Particularly, after holding at 1400 °C for 8 h,a number of β-SiC particles with an average size of 28 nm were in-situ precipitated and homogeneously dispersed in the amorphous SiBCN(O) matrix, compared with their counterpart experienced 2 h heat treatment, its nano-hardness, micro-region elastic modulus, flexural stress and elastic modulus were enhanced from ~5 GPa, ~50 GPa, ~40 MPa and ~10.7 GPa, to ~25 GPa, ~190 GPa, ~145 MPa and ~22 GPa, respectively.

中文翻译：

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SiC/SiBCN(O)纳米复合材料的原位制备及力学性能分析

摘要 本文以SiBCN(O)非晶陶瓷为原料，制备了致密且无明显裂纹和/或空隙的SiC/SiBCN(O)纳米复合材料。通过控制原材料在 1400°C 的热处理时间，纳米 β-SiC 晶粒原位生成并均匀分散在非晶 SiBCN(O) 陶瓷基体中，从而获得目标材料，这可能提供一种新的策略用于制造致密的 SiBCN(O) 基纳米复合材料。还研究了停留时间对材料化学成分、晶粒沉淀和力学性能的影响。实验结果表明，制备的 SiC/SiBCN(O) 纳米复合材料致密且无孔/裂纹，并且随着在 1400 ℃保温时间的增加，材料的化学成分变得更加均匀，其机械性能也显着提高。特别是，在 1400°C 保持 8 小时后，许多平均尺寸为 28 nm 的 β-SiC 颗粒原位沉淀并均匀分散在无定形 SiBCN(O)基体中，而它们的对应物经历了 2 小时热处理后，其纳米硬度、微区弹性模量、弯曲应力和弹性模量从~5 GPa、~50 GPa、~40 MPa和~10.7 GPa提高到~25 GPa、~190 GPa、~145 MPa和~22 GPa，分别。