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3D FEM simulations for the homogeneity of plastic deformation in Al–Cu alloys during ECAP
Mahallawy, Nahed El,Shehata, Farouk A.,Hameed, Mohamed Abd El,Aal, Mohamed Ibrahim Abd El,Kim, Hyoung Seop Elsevier 2010 Materials science & engineering. properties, micro Vol.527 No.6
<P><B>Abstract</B></P><P>Equal channel angular pressing (ECAP) is a material processing method that allows very high strains to be imposed, leading to extreme work hardening and microstructural refinement. To investigate the deformation homogeneity in the transverse direction, rigid-viscoplastic 3D finite element simulations were conducted for the different numbers of ECAP passes of Al with Cu contents 0–5%. The simulation results indicated that the material on the outer side of the die channel undergoes less deformation than that in the inner side due to the formation of a corner gap. It was also found that the homogeneity increased with increasing the number of ECAP passes and the copper content due to the decrease in the size of the corner gap. To verify the 3D finite element simulation results, the microhardness homogeneity across the transverse direction of the billet was measured. The same trend was observed: the homogeneity in hardness increased with increasing the number of ECAP passes and Cu contents from 0% to 5%. The homogeneity of deformation indicated by microhardness and by FEM results was higher for route A compared with route Bc and increases with the number of ECAP passes. The homogeneity in route A was higher than that in route Bc by 10% after 2 passes up to 8 passes.</P>
Tensile Properties and Fracture Characteristics of ECAP-Processed Al and Al-Cu Alloys
Mohamed Ibrahim Abd El Aal,Nahed El Mahallawy,Farouk A. Shehata,Mohamed Abd El Hameed,윤은유,이정환,김형섭 대한금속·재료학회 2010 METALS AND MATERIALS International Vol.16 No.5
In the present paper, billets of pure Al, and cast-homogenized Al-2 wt.%, 3 wt.%, and 5 wt.% Cu alloys were successfully processed by equal channel angular pressing (ECAP) up to 10 passes without fracture at room temperature using a die with a channel angle of 110o. Giant strains imposed on workpieces lead to extreme dislocation densities, microstructural refinement, and finally ultrafine grained materials. Tensile tests were employed to examine the fracture modes and fracture surface morphologies of the ECAP-processed Al and Al-Cu alloy samples. In particular, the effects of the number of ECAP passes and the Cu content were investigated.