Carbon-Carbon Composites (CCC) are widely used in the aviation industry for structural applications. Their main disadvantage is their low resistance to oxidation at elevated temperatures. While the CCCs are in service they might be exposed to different fluids which contain oxidation catalysts. Therefore, this paper examined the influence of service fluids widely used in aviation industry on oxidation and mechanical properties of aircraft brake disks made of 3D CCC. Isothermal oxidation of the CCC was investigated following immersion in either hydraulic fluid MIL-PRF-83282 or cleaning agent MIL-C-87937. The brake disks were evaluated using thermogravimetric analysis revealing that MIL-C-87937 is a catalyst for oxidation of carbon while MIL-PRF-83282 is not. Further investigation was performed by exposure to 700 °C in a cyclic manner followed by morphological characterizations using Scanning Electron Microscope (SEM). Mechanical properties were also characterized using a Dynamic Mechanical Analyzer in a 3-point bending mode and a universal testing machine in compression mode. SEM observations showed amplified oxidation evidence on samples exposed to MIL-C-87937. The morphological changes explain the resultant mechanical degradation: increase in tan (δ) by 220% with oxidation that begins at the fiber–matrix interface and decreased compression strength by 36%. When exposed to MIL-C-87937 cleaning agent, deterioration trend of these properties seems to be accelerated.

碳-碳复合材料（CCC）在航空工业中广泛用于结构应用。它们的主要缺点是在高温下抗氧化性低。在使用CCC时，它们可能会暴露于含有氧化催化剂的不同流体中。因此，本文研究了在航空工业中广泛使用的工作油对3D CCC制成的飞机制动盘的氧化和机械性能的影响。在浸入液压油MIL-PRF-83282或清洁剂MIL-C-87937中后，研究了CCC的等温氧化。使用热重分析法对制动盘进行了评估，结果表明MIL-C-87937是碳氧化的催化剂，而MIL-PRF-83282不是。通过以循环方式暴露于700°C，然后使用扫描电子显微镜（SEM）进行形态表征，进行了进一步的研究。机械性能还通过使用三点弯曲模式下的动态力学分析仪和处于压缩模式下的通用测试机进行了表征。SEM观察表明，暴露于MIL-C-87937的样品具有放大的氧化证据。形态变化解释了最终的机械降解：tan（δ）增加了220％，其中氧化作用始于纤维-基质界面，抗压强度降低了36％。当暴露于MIL-C-87937清洁剂时，这些性能的恶化趋势似乎正在加速。机械性能还通过使用三点弯曲模式下的动态力学分析仪和处于压缩模式下的通用测试机进行了表征。SEM观察表明，暴露于MIL-C-87937的样品具有放大的氧化证据。形态变化解释了最终的机械降解：tan（δ）增加了220％，其中氧化作用始于纤维-基质界面，抗压强度降低了36％。当暴露于MIL-C-87937清洁剂时，这些性能的恶化趋势似乎正在加速。机械性能还通过使用三点弯曲模式下的动态力学分析仪和处于压缩模式下的通用测试机进行了表征。SEM观察表明，暴露于MIL-C-87937的样品具有放大的氧化证据。形态变化解释了最终的机械降解：tan（δ）增加了220％，其中氧化作用始于纤维-基质界面，抗压强度降低了36％。当暴露于MIL-C-87937清洁剂时，这些性能的恶化趋势似乎正在加速。tan（δ）增加220％，而氧化作用始于纤维-基质界面，压缩强度降低36％。当暴露于MIL-C-87937清洁剂时，这些性能的恶化趋势似乎正在加速。tan（δ）增加220％，而氧化作用始于纤维-基质界面，压缩强度降低36％。当暴露于MIL-C-87937清洁剂时，这些性能的恶化趋势似乎正在加速。