The Finite Element Simulation And Experimental Investigation In Equal Channel Angular Pressing For Pure Al

Equal Channel Angular Pressing (ECAP) is a new processing procedure fabricating ultrafine grain material, it introduces severe shear deformation with lateral pressing, under the circumstance of not changing material composition and its size, it is the most effective method to refine grains and improve mechanical properties of material.According to the basic theory of ECAP, there are various factors which can influence grain refinement of ECAP technology, such as mold structure, pressing pass, and process route and so on. The influence of process route on grain refinement was studied in this paper. The software Deform-2D was adapted to study the rigid-plastic finite element simulation on the deformation process of99.7%commercial pure Al. The plastic flow, pressing force and the law of stress and the strain can be obtained. And combined with plastic forming theory, we can analyses the deformation mechanism of ECAP and design a new process route135. The cross-section shape dimension Φ40mm of99.7%commercial pure Al was used as the experimental material to do ECAP experiment at room temperature. In the ECAP, the new process route and the traditional four process routes (route A, BC, BA, C) was used and samples were left. The polarized light organization, hardness and TEM organization of the samples were observed to make comparative analysis. Commercial pure Al after ECAP was used as ordinary annealing material in order to analyze its complete recrystallization temperature and thermal stability. Commercial pure Al and high pure Al after ECAP were used as electromagnetic annealing material to analyze the influence of magnetic field in recrystallization process.The finite element simulation and experimental results show that the numerical simulation and the experimental results are identical with each other. In terms of grain refinement effect, the new route135is superior to route BC (had been considered to be the best of grain refinement). General annealing experiments show that the perfect recrystallization temperature of commercial pure Al after ECAP is between300℃and325℃, and the most even small grains are the annealing structure of the eighth sample of route135. Electromagnetic annealing experiments show that DC magnetic field has a certain extent of inhibition on recrystallization process of commercial pure Al and high pure Al, and has an effect on the grain feature of high pure Al after recrystallization.