Badea Teodor Adrian, Maier Lucia Raluca, Crisan Alexa-Andreea
Composite Materials Laboratory for Aeronautical Field, Romanian Research & Development Institute for Gas Turbines-COMOTI, 220D Iuliu Maniu Av., 061126 Bucharest, Romania.
Polymers (Basel). 2025 Sep 11;17(18):2462. doi: 10.3390/polym17182462.
The research investigated the potential of five novel additively manufactured (AM) fiber-reinforced thermoplastic composite (FRTPC) configurations as alternatives for ablative thermal protection system (TPS) applications. The thermal stability and ablative behavior of ten samples developed via fused deposition modeling (FDM) three-dimensional (3D) printing out of fire-retardant thermoplastics were investigated using an in-house oxyacetylene torch bench. All samples featured an innovative internal thermal management architecture with three air chambers. Furthermore, the enhancement of thermal benefits was achieved through several approaches: ceramic coating, mechanical hybridization, or continuous fiber reinforcement. For each configuration, two samples were exposed to flame at 1450 ± 50 °C for 30 s and 60 s, respectively, with the front surface subjected to direct exposure at a distance of 100 mm during the ablation tests. Internal temperatures recorded at two back-side contact points remained below 50 °C, well under the 180 °C maximum allowable back-face temperature for TPS during testing. Continuous reinforced configurations 4 and 5 displayed higher thermal stability the lowest values in terms of thickness, mass loss, and recession rates. Both configurations showed half of the weight losses measured for the other tested configurations, ranging from approximately 5% (30 s) to 10-12% (60 s), confirming the trend observed in the thickness loss measurements. However, continuous glass-reinforced configuration 5 exhibited the lowest weight loss values for both exposure durations, benefiting from its non-combustible nature, low thermal conductivity, and high abrasion resistance intrinsic characteristics. In particular, the AlO surface coated configuration 1 showed a mass loss comparable to reinforced configurations, indicating that an enhanced surface coat adhesion could provide a potential benefit. A key outcome of the study was the synergistic effect of the novel air chamber architecture, which reduces thermal conductivity by forming small internal air pockets, combined with the continuous front-wall fiber reinforcement functioning as a thermal and abrasion barrier. This remains a central focus for future research and optimization.
该研究调查了五种新型增材制造（AM）纤维增强热塑性复合材料（FRTPC）结构作为烧蚀热防护系统（TPS）应用替代品的潜力。使用内部氧乙炔焊炬试验台，研究了通过熔融沉积建模（FDM）三维（3D）打印由阻燃热塑性塑料制成的十个样品的热稳定性和烧蚀行为。所有样品均具有带有三个气室的创新内部热管理结构。此外，通过几种方法实现了热效益的提高：陶瓷涂层、机械混合或连续纤维增强。对于每种结构，分别将两个样品在1450±50°C的火焰中暴露30秒和60秒，在烧蚀测试期间，前表面在100毫米的距离处直接暴露。在两个背面接触点记录的内部温度保持在50°C以下，远低于测试期间TPS允许的180°C最大背面温度。连续增强结构4和5表现出更高的热稳定性，在厚度、质量损失和退缩率方面的值最低。两种结构的重量损失均为其他测试结构测量值的一半，范围从大约5%（30秒）到10 - 12%（60秒），证实了在厚度损失测量中观察到的趋势。然而，连续玻璃纤维增强结构5在两种暴露持续时间下均表现出最低的重量损失值，这得益于其不可燃的性质、低导热性和高耐磨性等固有特性。特别是，AlO表面涂层结构1的质量损失与增强结构相当，表明增强的表面涂层附着力可能会带来潜在益处。该研究的一个关键成果是新型气室结构的协同效应，它通过形成小的内部气穴降低了热导率，再加上连续的前壁纤维增强起到了热障和耐磨障的作用。这仍然是未来研究和优化的核心重点。
