Artificial intelligence algorithms including two artificial neural network and two machine learning algorithms were employed to predict the four-ball tribology behavior of MoS₂-Al₂O₃ hybrid nanofluid. MoS₂-Al₂O₃ composite nanoparticles were synthesized using solvothermal method and then dispersed in water-based fluids. 27 groups of tribology tests were conducted according to Box-Behnken experimental design were set as the training groups. The input variables (velocity of friction pairs, test force, test temperature, nanoparticle concentration) and output parameters (friction coefficient, wear scar diameter, wear surface roughness) were selected as the main variables. It was found that the random forest (RF) had better predict accuracy and stability for the four-ball tribology behavior of MoS₂-Al₂O₃ nanofluid than multilayer perceptron (MLP), back propagation (BP) and k-nearest neighbors (KNN) algorithms. Besides, Pearson correlation analysis was carried out to reveal the relationship between input and output as well as different output variables. Through in-depth characterization of worn surface, a tribofilm in the thickness of 15 ∼ 20 nm composed of amorphous phases, ultra-fine nanoparticles and iron compounds was found. Finally, the lubrication mechanism of MoS₂-Al₂O₃ nanofluid were discussed based on analyzing the tribology behavior data and tribofilm structure. Through the above findings, we hope to promote the application and development of artificial intelligence techniques in lubricants design and performance evaluation in the future.

中文翻译：

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利用人工智能预测MoS2-Al2O3混合纳米流体的摩擦学行为

摘要采用人工智能算法（包括两种人工神经网络和两种机器学习算法）来预测MoS2-Al2O3混合纳米流体的四球摩擦学行为。采用溶剂热法合成MoS2-Al2O3复合纳米粒子，然后分散在水基流体中。按照Box-Behnken实验设计进行27组摩擦学测试作为训练组。选择输入变量（摩擦副速度、试验力、试验温度、纳米粒子浓度）和输出参数（摩擦系数、磨痕直径、磨损表面粗糙度）作为主要变量。结果发现，随机森林（RF）对于MoS2-Al2O3纳米流体的四球摩擦学行为比多层感知器（MLP）、反向传播（BP）和k近邻（KNN）算法具有更好的预测精度和稳定性。此外，还进行了皮尔逊相关分析，以揭示输入和输出以及不同输出变量之间的关系。通过对磨损表面的深入表征，发现了由非晶相、超细纳米颗粒和铁化合物组成的厚度为15~20 nm的摩擦膜。最后，通过分析摩擦学行为数据和摩擦膜结构，讨论了MoS2-Al2O3纳米流体的润滑机理。通过以上研究结果，我们希望未来能够推动人工智能技术在润滑油设计和性能评估中的应用和发展。