Abstract Silicone-based composites material as Thermal Protection System (TPS) found a large use in the aerospace industry to protect wall structures from severe heating (airframe or propulsion parts, including ramjet type). The matrix of the composite material is often reinforced with fillers, such as Carbon Fibres (CFs) and Silicon Carbide Powder (SCP). This formulation aims to improve the thermomechanical properties which leads to significant impact on the thermophysical parameters (λ, ρ, cp). The present work consists of studying the effect of the CFs and SCP contents on the thermophysical properties evolution. For this purpose, three samples of silicone-based composites, referenced as M1, M2 and M3, are prepared by MBDA–France. The difference among the three samples is in the CFs and SCP contents in each sample. Firstly, some experimental studies were conducted to determine the thermophysical properties (λ, ρ, cp) in a temperature range from room temperature to 1000 °C. Dedicated experimental apparatus are used: dilatometry for density measurement, Calvet calorimeter combined with Differential Scanning Calorimetry (DSC) experiments for specific heat capacity determination, and finally laser flash analysis for thermal diffusivity measurement leading to the thermal conductivity calculation. Secondly, the measured thermophysical properties are used in a 1D numerical procedure using Amaryllis modulus of the SAMCEF™ finite element code in order to investigate the thermal efficiency of the materials as TPS. The comparison of the results confirms that the three silicone-based composites, M1, M2, M3, behave as efficient thermal barriers when exposed to severe heat fluxes. The lower the amount of CF, the higher the thermal efficiency. To a lesser extent, an increase in the amount of SCP tends to improve the insulation efficiency.

中文翻译：

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增强硅基复合材料热降解的实验和数值分析：碳纤维和碳化硅粉末含量的影响

摘要 作为热保护系统 (TPS) 的硅基复合材料在航空航天工业中被广泛用于保护壁结构免受严重加热（机身或推进部件，包括冲压式喷气发动机）。复合材料的基体通常用填料增强，例如碳纤维 (CFs) 和碳化硅粉末 (SCP)。该配方旨在改善热机械性能，从而对热物理参数（λ、ρ、cp）产生重大影响。目前的工作包括研究 CFs 和 SCP 含量对热物理性质演变的影响。为此，MBDA-France 制备了三个有机硅基复合材料样品，分别称为 M1、M2 和 M3。三个样本之间的差异在于每个样本中的 CF 和 SCP 含量。首先，进行了一些实验研究以确定从室温到 1000 °C 的温度范围内的热物理特性（λ、ρ、cp）。使用专用的实验设备：密度测量膨胀法，Calvet 量热仪结合差示扫描量热法 (DSC) 实验确定比热容，最后激光闪光分析用于热扩散率测量，导致热导率计算。其次，使用SAMCEF™ 有限元代码的阿玛丽利斯模量在1D 数值程序中使用测量的热物理特性，以研究作为TPS 的材料的热效率。结果的比较证实，三种硅基复合材料 M1、M2、M3 在暴露于严重的热通量时表现出有效的隔热层。CF的量越少，热效率越高。在较小程度上，SCP 量的增加倾向于提高绝缘效率。