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Accurate prediction of the remaining useful life (RUL) of bearings is crucial for maintaining the reliability and efficiency of industrial systems. This study introduces a novel methodology integrating advanced machine learning and optimization techniques to address this challenge. (1) A transformer-attention model was developed to process segmented vibration signals, effectively capturing complex patterns. The model showed better performance than traditional approaches, with an RMSE of 0.989. (2) A Deep Neural Network (DNN) was designed to predict the extended RUL of bearings after laser shock peening (LSP) remanufacturing. The fruit fly optimization (FFO) algorithm was employed to optimize the remanufacturing parameters; a 29.33% improvement was achieved in fitness compared to the baseline. (3) The DNN model predictions were validated against Finite Element Analysis (FEA) simulations, with a low relative error of 2.5% to 5.8%; the model showed good accuracy in capturing the effects of optimized LSP parameters on bearing life extension. [ABSTRACT FROM AUTHOR]

Corrugated damage to bearings is a common fault in electrical facilities such as new energy vehicles, wind power, and high-speed railways. The aim of this article is to reveal the microscopic characteristics and formation mechanism of such damages. The corrugation with alternating "light" and "dark" shape was produced on GCr15 bearing races in the experimental conditions. Compared to the light area, the dark area (in the images generated by optical microscope) has more severe electrical erosion, lower hardness, more concave morphology, and lower oxidation. As the voltage increases, the width of the corrugation, the height difference between corrugation, and surface roughness all increase. It is believed that the formation of corrugated damage requires a sufficiently high voltage to induce the periodic destruction and reconstruction of the lubrication film. When the bearing is in a metal-lubrication film–metal contact state, the high voltage causes the lubrication film to break down and induce electrical erosion. Then, the contact area is in metal–metal contact, and the surface is mainly damaged by mechanical rolling. After the reconstruction of lubrication film, the next round of electrical erosion begins. The results are helpful for a deeper understanding of the mechanism of bearing erosion in electrical application. [ABSTRACT FROM AUTHOR]

Lubricant additive plays an important role in reducing the friction and wear for base oil. MAX phase ceramics may have superior advantages for additive application due to their unique nanolayered structure. In this paper, Ti2SnC ceramic is prepared by sintering the elemental mixtures at 1250 °C. In addition, Cu-coated Ti2SnC ceramic is successfully prepared using a chemical plating method for the first time. It is confirmed that the Ti2SnC ceramic has good self-catalytic activity, and a layer of stacking Cu nano-particles can be deposited on the Ti2SnC surface without pretreatment. When the Cu-coated Ti2SnC ceramic powder is doped into PAO10 base oil, the oil can exhibit excellent lubrication properties, where the friction coefficient is as low as 0.095. A layer of tribo-film can be formed during the sliding process when the Cu-coated Ti2SnC ceramic is incorporated into PAO10 base oil, which can reduce the friction coefficient. The superior lubrication properties can be attributed to the synergistic lubrication effect of Ti2SnC ceramic and Cu nano-particles. [ABSTRACT FROM AUTHOR]

The application of C/C composites in finger seals can effectively solve the problem of seal wear due to its excellent tribological and mechanical behaviors. However, the designable characteristics of composites, such as the density and orientation of fabric on the friction plane, have a very important influence on the tribological properties and service life of sealing materials. In order to obtain a better material design scheme for the C/C composite on the finger seal, it is necessary to conduct research on the tribological properties and wear mechanism of the C/C composite based on the working conditions of the finger seal. Therefore, a reciprocating tribo-tester was used to conduct the test by abrading the C/C composite disk with a pin made of 1045,080M46. The effects of material density, fabric orientation, and load and sliding velocity on the tribological properties and wear mechanism of the C/C composite were studied. The results show that the friction coefficient and wear rate of the composite with a perpendicular orientation (non-woven cloth perpendicular to the friction plane) were lower than those with a parallel orientation (non-woven cloth parallel to the friction plane). The tribological properties with higher density are better than those of material with a lower density. The friction coefficient of low-density material increases with the load, whereas it decreases gradually with high-density material. The wear rate increases with the load for two-density materials. With the increase in the sliding velocity, the friction coefficient decreases. The wear rate of low-density material decreases significantly, whereas it changes little with high-density material. The influence of the sliding velocity on the friction and wear properties of the C/C composite is greater than that of the load. This study provides a feasible material design idea for effectively alleviating the wear of finger seals. [ABSTRACT FROM AUTHOR]

MoSN/MoS2 multilayer films were deposited by a sputtering MoS2 target in alternate Ar and Ar/N2 mixed atmospheres with different nitrogen flow rates. The influence of nitrogen flow rates on the microstructure, mechanical and tribological properties of the prepared films were investigated. The multilayer film exhibited the preferred orientation of (002) plane for MoS2 sublayers and amorphous structure for MoSN sublayers. Introducing N2 into the source gas resulted in a much more compact structure for multilayer films due to the suppression of columnar growth of MoS2 film. With the increase of the nitrogen flow rate, the hardness of the multilayer film firstly increased from 2.3 to 10.5 GPa as the nitrogen flow rate increased from 4 to 10 sccm and then turned downwards to 6.5 GPa at 20 sccm. MoSN/MoS2 film deposited with an optimized microstructure exhibited low friction coefficients below 0.03 and a wear life higher than 1.8×105 revolutions in vacuum. Meanwhile, the optimized film showed an ultralow friction coefficient of 0.004~0.01 and wear rate of 4.7 × 10−7 mm3/N·m in an ultrahigh vacuum. Both the enhanced hardness by N-doping and sustainable formed MoS2 tribofilm contributed to the improved tribological property of MoSN/MoS2 multilayer film. [ABSTRACT FROM AUTHOR]