Search

The metal flow is complicated and will be affected by the dimensions of the rolling deformation zone during the rolling of doubly curved sheet metal surfaces. The dimensions of the rolling deformation zone are mainly affected by the rolling reduction and the central cross-section diameters of rollers. The work studied the influences of central cross-section diameters of rollers on the longitudinal bending deformation of formed spherical surfaces and the stability of the rolling process combined with the rolling reduction. The results showed that the larger the central cross-section diameters of rollers, the more stable the rolling process, and the better the shape accuracy of formed spherical surfaces. When the central cross-section diameters of rollers were relatively small, the longitudinal bending deformation of formed spherical surfaces increased with the increased central cross-section diameters of rollers. However, an excessively large roller diameter restrained the longitudinal bending deformation of the sheet. When the central cross-section diameters of rollers were relatively large, the longitudinal bending deformation of formed spherical surfaces decreased with the increased central cross-section diameters of rollers. The results can be used as a reference for designing rollers to ensure that formed doubly curved surfaces can obtain greater longitudinal bending deformations and better shape accuracy under the same rolling reduction. [ABSTRACT FROM AUTHOR]

The 3D curved parts rolling based on rigid arc-shaped rollers is a novel plastic forming process for rapidly manufacturing curved parts with double curvature. This work proved that the method can form different types of 3D curved parts through small adjustments of the rolling reduction without replacing the rollers. The study found that when the generatrix radius of the convex roller is smaller than that of the concave roller, the distribution rule of uneven roll gap could vary with the change of the rolling reduction. Therefore, the forming method can change the distribution rule of uneven roll gaps by adjusting the rolling reduction to form different types of curved parts (spherical parts, saddle-shaped parts, or cylindrical parts). The relationship between the rolling reduction and the distribution rule of roll gaps is studied by analytical, finite element, and experiment method. And the influence of the rolling reduction on the bending deformation of different types of curved parts is studied. The research results show that the longitudinal bending deformation of formed curved parts is greatly affected by the rolling reduction. The longitudinal curvature of formed saddle-shaped parts decreases with the increase of the rolling reduction, and the longitudinal curvature of formed spherical parts increases with the increases of the rolling reduction. The transverse bending deformation of formed curved parts is little affected by the rolling reduction. [ABSTRACT FROM AUTHOR]

A one-dimensional yolk-shell Sb2O3/TiO2 composite with excellent lithium-storage properties has been successfully fabricated, including preparation of one-dimensional Sb2O3 precursor and coating of TiO2 film. As an anode material for lithium-ion batteries (LIBs), the Sb2O3/TiO2 composite can display the initial discharge specific capacity of 1285 mAh g−1 at a current density of 100 mA g−1 and maintain a discharge specific capacity of 579 mAh g−1 after 100 cycles, approximately 2.7 times as high as the pure Sb2O3. The excellent lithium-storage properties can be attributed to the synergistic effect between the one-dimensional structural Sb2O3 and the TiO2 film, in which the external TiO2 shell can effectively restrain the volume expansion during the charge and discharge cycle, making the electrochemical reaction highly reversible. [ABSTRACT FROM AUTHOR]