Equal Channel Angular Pressing(ECAP) is currently one of the most popular methods for fabricating Ultra-Fine Grained(UFG) materials.In this work,ECAP process has been performed on commercial pure aluminum up to 8 passes by route A.After verification of FEM work,the influences of four die channel angles,three outer corner angles and pass number up to 8 have been analyzed to investigate strain distribution behavior of ECAPed material.Two methods for quantifying the strain homogeneity namely inhomogeneity index(Ci) and standard deviation(S.D.) are compared.It is shown that Ci is not a good candidate for examining the strain distribution uniformity.Moreover,it is suggested that designing of ECAP die geometry to achieve optimum strain distribution homogeneity is more suitable than the optimum effective strain magnitude.The best strain distribution uniformity in the transverse plane is obtained with Ф=60° and Ψ=15° and for the bulk of the sample,Ф=120° and Ψ=15° or 60°,gives the highest strain dispersal uniformity.

Equal channel angular pressing (ECAP) is a type of severe plastic deformation procedure for achieving ultra-fine grain structures. This article investigates artificial neural network (ANN) modeling of ECAP process based on experimental and three-dimensional (3D) finite element methods (FEM).In order to do so, an ECAP die was designed and manufactured with the channel angle of 90° and the outer corner angle of 15°. Commercial pure aluminum was ECAPed and the obtained data was used for validating the FEM model. After confirming the validity of the model with experimental data, a number of parameters are considered. These include the die channel angles (angle between the channels Φ and the outer corner angle Ψ) and the number of passes which were subsequently used for training the ANN. Finally, experimental and numerical data was used to train neural networks. As a result, it is shown that a feed forward back propagation ANN can be used for efficient die design and process determination in the ECAP. There is satisfactory agreement between results according to comparisons.

Hydrogen is expected to be a viable solution for green-energy investment in future. However, hydrogen storage is a big challenge for stationary and mobile applications. Severe Plastic Deformation (SPD) techniques are well-known to be effective in enhancement of hydrogenation in metals hydrides. This paper shows the effect of a novel SPD technique named “High Pressure Torsion Extrusion-HPTE” on the hydrogenation of metal hydrides and compare it with the conventional method of ECAP. Results of mechanical testing and X-ray diffraction patterns showed significant enhancement in hardness and microstructural refinement in materials after HPTE. Accordingly, hydrogenation kinetics improved dramatically. This achievement could be an initiative to implement HPTE in synthesis of metal hydrides for clean energy applications.