Variation in microstructural features of 2024 aluminum alloy plastically deformed by equal channel angular pressing (ECAP) at room temperature, was investigated by X-Ray diffraction in this work. These include dislocation density dislocation characteristic and the cell size of crystalline domains. Dislocations contrast factor was calculated using elastic constants of the alloy such as C 11, C 2...

The main aim of the current project has been to produce a batch of bulk billets with ultrafine-grained (UFG) microstructure and enhanced strength made of two refractory metals such as tungsten and tantalum. To process bulk W billets with UFG structure having a long-length size more than 100 mm we have developed and successfully used a new approach based on a combination of equal angular pressin...

Despite extensive literature consisting of many excellent academic and practical papers, there are still many commonly heard fallacies in practice such as: “To aggregate risks, all I need are correlations”. “I assume dependence/independence, hence there is no copula”. “I need to use a Variance-Covariance approach with tail-end correlations to capture fat tails and tail dependence”. “The mere ex...

Recent developments in nanostructured products draw considerable attention to ultrafine grained materials. These materials are normally manufactured by different severe plastic deformation (SPD) methods. In the present study, analytical models and finite element method (FEM) are used to calculate strain imposed to a specimen that was deformed by equal channel angular pressing (ECAP). In additio...

The focus of this study was on the effect channel angle stress distribution in material aluminum alloy 5083. mechanical properties a mate- rial are related to grain size. Equal angular pressing (ECAP) is method for deforming materials such way that strong prop- erties formed while dimensions work piece stay fixed order make ultra-fine-grained materials. One parameters ECAP angle. It’s crucial u...

Equal Channel Angular Pressing (ECAP) is currently being widely investigated because of its potential to produce ultrafine grained microstructures in metals and alloys. A sound knowledge of the plastic deformation and strain distribution is necessary for understanding the relationships between strain inhomogeneity and die geometry. Considerable research has been reported on finite element analy...

2007 was the first international congress on the “square of oppositions”. A first attempt to structure debate using n-opposition theory was presented along with the results of a first experiment on the web. Our proposal for this paper is to define relations between arguments through a structure of opposition (square of oppositions is one structure of opposition). We will be trying to answer the...