Based on the multi-field coupling effect of temperature, diffusion, and phase change, the finite element model of carburizing and quenching was established. The 20CrMnTiH steel helical gear as the research object, prediction accuracy of carburizing, and quenching model of complex helical gear was studied. The material properties database of experimental steel was established by JMatPro, and the material thermophysical parameters needed in the calculation process were obtained. The carburizing and quenching process of transmission helical gear was numerically simulated by thermodynamic three-dimensional coupling analysis method combined with actual heat treatment process. The microstructure morphology, macro hardness, and deformation were characterized. The experimental results show that the microstructure of the hardened surface layer was acicular martensite and a small amount of residual austenite. The highest hardness appears at the surface layer of 778.8 HV, the effective hardened layer depth was 0.9 mm, and the maximum deformation of the gear was 0.055 mm. By comparing the experimental measurement results with the simulation results, they were in good agreement, which verifies the accuracy of the finite element model. This indicates that the model has good prediction ability in carburizing and quenching process.

In this research, Al-doped and (Al, Fe) codoped ZnO films were prepared on glass substrate by the sol–gel method. The surface morphology, structure, and optical property were characterized by scanning electron microscope (SEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and Ultraviolet-Visible-Near-infrared (UV-Vis-NIR) spectroscopy. The film surface morphologies all exhibited granular characteristics. With the Fe doping concentration increasing, the codoped films had smaller grain size and tended to be smoother. XRD analysis revealed that all films had a hexagonal wurtzite structure. The codoping can contribute to more Al and Fe ions entering the ZnO crystal structure, but result in the crystalline degree of the films decreasing. XPS results showed that the Al and Fe irons in the films exist in the form of trivalent. Moreover, the doped films had higher transmission, especially for codoped (Fe:Al = 3) film, but their absorption edge shifted to the short-wavelength direction.

Protective coating is an effective way to extend materials’ high-temperature service life. In order to improve the high-temperature oxidation resistance of AISI 304 stainless steel, mullite films with different layers were successfully prepared by the sol-gel method and the sintering process on the surface of stainless steel. The effect of the film layers on the high-temperature oxidation resistance of stainless steel at 900 °C for 100 h was studied. The analysis results of oxidation kinetics, X-rays diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive analysis (EDS) show that Al_1.4Si_0.3O_2.7 mullite film effectively improved the high-temperature oxidation resistance of stainless steel. The sample with three-layer mullite film has the best high-temperature oxidation resistance. The mass gain and oxidation spalling mass are only 4.6% and 34.5% of those of the uncoated sample after 100 h cyclic oxidation at 900 °C. A chromium oxide layer was formed at the interface of mullite film and the substrate during the sintering process. The generation of selective Cr₂O₃ scale was promoted at the cyclic oxidation stage so that the sample with three-layers has excellent high-temperature oxidation resistance.

Bearing rings are thin-walled components prone to distortion during quenching. Achieving high-precision distortion control for bearing rings remains a critical challenge in high-precision bearing manufacturing. This paper proposes an AI-driven method for distortion control during bearing ring quenching in mesh-belt furnaces. The primary objective is to identify the optimal reverse motor frequency within the furnace. An experimental database is established using distortion results obtained at different reverse motor frequencies. This database serves as training data for deep learning. Subsequently, a large language model (LLM) employs few-shot learning to optimize and predict the reverse motor frequency influencing bearing quenching distortion. Results demonstrate that the LLM method achieves significantly higher prediction accuracy than traditional machine learning approaches. The optimization outcomes validate the effectiveness of generative AI in optimizing the reverse motor frequency of mesh-belt furnaces and controlling distortion during bearing ring quenching.

In this study, Finite elements method (FEM) was used for simulations on the annealing treatment. And the distributions of residual stress were obtained from the resualts of simulitions. Besides, in order to study the mechanical properties. Composite plates of AZ31B magnesium alloys and 6061 aluminum alloys were fabricated by vacuum diffusion bonding method. Then experiments about annealing, measurement of residual stresses and tension test were also carried out. The results of residual stresses obtained by X-ray diffraction (XRD) were compared with the results of simulations. It can be thought that the results of residual stress obtained from simulations and that from experiments are in a good agreement. What’s more, The residual stress after annealing at 250°C is the least of all, while the tensile strength is the strongest. On the basis of results of simulations and experiments, the conclusion can be obtained that 250°C is the most appropriate annealing temperature.