In this study, a nanoscale ionic liquid (NIL) GO@SiO₂ hybrid was synthesized by attaching silica nanoparticles onto graphene oxide (GO). It was then functionalized to exhibit liquid-like behavior in the absence of solvents. The physical and chemical properties of the synthesized samples were characterized by means of a transmission electron microscope, X-ray diffraction, Fourier transform infra-red, Raman spectroscopy, and thermogravimetric analysis. The tribological properties of the NIL GO@SiO₂ hybrid as a water-based (WB) lubricant additive were investigated on a ball-on-disk tribometer. The results illustrate that the NIL GO@SiO₂ hybrid demonstrates good dispersity as a WB lubricant, and can decrease both the coefficient of friction (COF) and wear loss.

This study investigates the Inconel 718 alloy coated with NiCrBSi powder using the ABAQUS software. An accurate conical heat source model is constructed based on the three-dimensional Fourier heat conduction law. The heat source subroutine Dflux.for is successfully integrated to achieve a highly realistic simulation of the welding heat source. Using this model, the analysis focuses on the temperature distribution in electron beam melting. Furthermore, the accuracy and reliability of the simulation are validated through actual coating experiments. By examining the impact of various procedural factors on the temperature distribution, it is found that optimal coating results and a tightly formed elliptical molten zone are attained at an electron beam current of 18 mA, and the scanning speed is 300 mm/min. The peak temperature in the melt pool in the coating area is 5087 K, while the lowest temperature on the isothermal in the heat-affected zone is 1409 K. Over time, there is a swift rise in temperature for the data points taken along both the X and Z trajectories, followed by rapid cooling after rapid heating. Coating experiments conducted under the optimal parameters demonstrate a dense coating layer and good bonding with the substrate, thereby validating the accuracy of the simulation.

High-carbon–chromium martensitic stainless steel (MSS) is widely used in many fields due to its excellent mechanical properties, while the coarse eutectic carbide in MSS deteriorates corrosion resistance. In this work, nitrogen was added to the MSS to improve corrosion resistance. The effects of nitrogen on the microstructure and corrosion resistance of MSS were systematically studied. The results showed that the addition of nitrogen promoted the development of Cr₂N and reversed austenite, effectively inhibiting the formation of δ-ferrite. Therefore, the durability of the passivation film was improved, the passivation zone was expanded, and the susceptibility to metastable pitting was decreased. As a consequence, nearly two orders of magnitude have been achieved in the pitting potential (E_pit) of MSS containing nitrogen, and the polarization resistance value (R_p) has gone up from 4.05 kΩ·cm² to 1.24 × 10² kΩ·cm². This means that in a corrosive environment, nitrogen-treated MSS stainless steel is less likely to form pitting pits, which further extends the service life of the material.

Nickel-based superalloys have excellent high temperature resistance and corrosion resistance, and can be used as candidate materials for superheater and reheater pipes of advanced ultra-supercritical thermal power units. This research focuses on the hot-compression behavior of nickel-based alloys in the deformation process range of strain rate 0.01–10 s⁻¹, deformation temperature 950–1150 °C, and deformation amount of 60%. The stress-strain curve collected during the hot compression process showed an obvious unimodal phenomenon, and showed obvious hardening and softening characteristics. The flow stress is very sensitive to the change of strain rate. The experimental results are used to develop plastic flow stress models for various existing constitutive models, namely Modified Johnson-Cook (MJC), Modified Zerilli-Armstrong (MZA), Strain-Compensated Arrhenius (SCA), Modified Fields-Backofen (MFB), Modified Hansel-Spittel (MHS), Piecewise Function (PF). Combined with correlation coefficient, average absolute relative error and relative error, the prediction accuracy of each model was further analyzed, and it was found that SCA and PF had better accuracy. The reasons for the errors of each model are further discussed. In addition, compared with SCA model, PF model has higher accuracy in predicting hardening stage and less calculation. The PF model has great potential in predicting the flow properties of materials.