Abstract Directional SiC honeycomb/Al–Mg–Si composites with different Si alloying contents (2–12 wt%) were prepared by spontaneous infiltration. The effect of Si alloying content on the phase composition, microstructure and thermophysical properties of the composites were investigated. The results showed that the equilibrium contact angles between the SiC ceramic and different Al alloys were in the range of 60.5–72° at 1273 K, benefitting the infiltration process. Meanwhile, the Si alloying content not only changed the phase composition of the composites, but also influenced the microstructure of the infiltrated Al alloys, especially changing the microstructure of Mg2Si phase from small flake-like eutectic phase (Mg2SiE) to large polygon-like primary phase (Mg2SiP). Due to the anisotropic feature of SiC honeycomb and the tunable phase composition and microstructure of the infiltrated Al alloys, the composites exhibited anisotropic and tailored thermophysical characteristics. The composites with the Si alloying content of 7 wt% possessed the optimum properties, with the highest TC of 140.95 W m−1 K−1 in axial direction and relatively low CTE of 11.1 × 10−6/K in radial direction. Additionally, the reduction of anisotropy of composites’ CTEs in two principal directions with the increase of Si alloying content was also discussed.

中文翻译：

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Si合金化含量对自发渗透制备的SiC蜂窝/Al-Mg-Si复合材料组织和热物理性能的影响

摘要 通过自发渗透制备了具有不同 Si 合金含量（2-12 wt%）的定向 SiC 蜂窝/Al-Mg-Si 复合材料。研究了Si合金化含量对复合材料相组成、显微组织和热物理性能的影响。结果表明，在 1273 K 时，SiC 陶瓷与不同铝合金之间的平衡接触角在 60.5-72° 范围内，有利于渗透过程。同时，Si合金化含量不仅改变了复合材料的相组成，而且影响了渗入铝合金的显微组织，尤其是将Mg2Si相的显微组织从小的片状共晶相（Mg2SiE）转变为大的多边形初晶相。相 (Mg2SiP)。由于 SiC 蜂窝的各向异性特征以及渗透铝合金的可调相组成和微观结构，复合材料表现出各向异性和定制的热物理特性。Si 合金含量为 7 wt% 的复合材料具有最佳性能，轴向最高 TC 为 140.95 W m-1 K-1，径向 CTE 较低，为 11.1 × 10-6/K。此外，还讨论了随着Si合金含量的增加，复合材料CTE在两个主要方向上的各向异性降低。轴向为 95 W m-1 K-1，径向 CTE 相对较低，为 11.1 × 10-6/K。此外，还讨论了随着Si合金含量的增加，复合材料CTE在两个主要方向上的各向异性降低。轴向为 95 W m-1 K-1，径向 CTE 相对较低，为 11.1 × 10-6/K。此外，还讨论了随着Si合金含量的增加，复合材料CTE在两个主要方向上的各向异性降低。