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Constrained groove pressing is a simple and effective method of grain refinement. Using the experimental data obtained by regression analysis, this paper analyzes the simulation of the four pass constrained groove pressing deformation of 7050 aluminum alloy. The simulation results show that the grain size of the billet is refined significantly after four pass constrained groove pressing deformation and decreases from the original 90 μm to a minimum of 14.0 μm. With the increase of the number of deformation passes, refinement effect becomes weakened gradually, the grain size tends to stabilize and the organization is more uniform.

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The paper focuses on the research of using the coupled thermo mechanical analysis method of rigid viscoplastic finite element and the evolution of dynamic recrystallization to establish the calculation model coupling factors of deformation, heat conduction, dynamic recrystallization in the DEFORM, and on the hot-forging simulation of AISI4140. Through the simulation, it makes a valid prediction of dynamic recrystallization volume fraction and the grain size of recrystallized during the metal hot-forging process.

Color difference on surface of aluminum alloy stripes when lubricated with oil-water mixtures in cold continuous rolling process was researched. The surface profile, 3D and micro morphology were observed by surface surface profiler, laser scanning confocal microscopeand scanning electron microscope. The chemical composition of aluminum surface was analyzed by X-ray energy dispersive spectrometer, and then the formation mechanism of color difference was studied. The results indicate that lubricated with oil-water mixture, oil and water can't mix sufficiently and lubrication failure was found in deformation zone because of lubrication oil shortage. Working roller and fresh surface of stripes contacted directly and leaded to adhesive, so lots of irregular shaped micro-cracks were found after rolling, the residual composition of oil-water mixture adsorbed in the micro-cracks and not easy to be cleaned up, so the organic matter of residue composition carbonized and manifested as color difference in the visible. The fringes of color difference are distributed approximately along the rolling direction and the average roughness was very nearly the same between different kinds of fringes.