ABSTRACT One of the key reasons for the failure of lube oils is their thermal degradation owing to elevated heat conditions in vehicle engines. In this study, the thermal degradation studies of the lube oils were performed using a simultaneous thermal analyzer (TGA/DTG/DSC). Furthermore, the engine thermal efficiency was determined experimentally using an AVL dynamometer under different operating conditions. TGA results showed that the oxidation onset temperature and burnout temperature of Al2O3/TiO2 hybrid nanolubricants could be delayed by 54.9 °C and 38.7 °C, respectively, as compared with the reference oil (5W-30). Comparing the engine results, the Al2O3/TiO2 nanolubricants presented enhancement of heat transport characteristics and brake thermal efficiency by 9–14% and 3.9–8.6%, respectively, compared with the reference oil. Hence, the high thermal stability of Al2O3/TiO2 nanolubricants allows to be used in a wide temperatures range with a higher fuel economy, optimize lube oil drain intervals and reduce maintenance costs in vehicles.

中文翻译：

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使用Al2O3/TiO2纳米材料提高汽车发动机油的传热能力和热稳定性

摘要 润滑油失效的主要原因之一是由于车辆发动机高温条件下的热降解。在这项研究中，润滑油的热降解研究是使用同步热分析仪 (TGA/DTG/DSC) 进行的。此外，发动机热效率是使用 AVL 测功机在不同操作条件下通过实验确定的。TGA 结果表明，与参考油 (5W-30) 相比，Al2O3/TiO2 混合纳米润滑剂的氧化起始温度和燃尽温度可分别延迟 54.9°C 和 38.7°C。比较发动机结果，与参考油相比，Al2O3/TiO2 纳米润滑剂的传热特性和制动热效率分别提高了 9-14% 和 3.9-8.6%。因此，