Two-parameter Rigid Block Approach to Upper Bound Analysis of Equal Channel Angular Extrusion Through a Segal 2θ-die

Abstract

This article deals with a phenomenological description of experimentally determined complex geometric shape of material dead zone during Equal Channel Angular Extrusion (ECAE) through a Segal 2θ-die with a channel intersection angle of 2θ>0° and 2θ<180°. Taking into account the complex dead zone geometry in a 2θ-die, a two-parameter Rigid Block Method (RBM) approach to a two-parameter Upper Bound Method (UBM) has been introduced with Discontinuous Velocity Field (DVF) for planar flow of plastic incompressible continua. The two-parameter UBM has allowed us to derive the numerical estimations for such energy-power parameters of ECAE as punching pressure and accumulated plastic strain for 2θ-dies. The obtained computational data have been compared with the one-parameter analytic UBM solution. Good agreement between the two computational results has been found.

CFD 2D Description of Local Flow of Polymer Workpiece through a modified U-Shaped Die During Equal Channel Multiple Angular Extrusion

“…(3,4) ) determine the kinematic and dynamic features of the local flow, rotation angles of the principal axes of the flow, and the heterogeneity of material rotation during workpiece forming through the U-die. However the dynamics of macroscopic rotation during workpiece ECMAE through a U-shaped multiple-angle die is still not fully addressed in the previous known research (1,(3)(4)(5)(6)(7)(8)(9)(10) , which emphasizes the importance and novelty of the present article.…”

“…Computational Fluid Dynamics (CFD) techniques (3)(4)(5)(6)(7)(8)(9)(10)(11) are finding new and important industrial applications in the materials science related fields of Severe Plastic Deformation (SPD) (1,3,(5)(6)(7)(8)(9)(10) . Minakowski (2014) has applied CFD-based techniques to a mathematical description of the flow of an aluminum workpiece during Equal Channel Angular Extrusion (ECAE) through a 2-turn angular die with internal and external radii in the channel intersection zones (3) .…”

“…Possible applications for ECMAE worked polymers are associated with aeronautical and chemical industry equipment production (1,(4)(5)(6)(7)(8) . The solution of the above mentioned technological problems is within the aims and scopes of research, conducted by Beloshenko et (5)(6)(7)(8)(9) , and Rejaeian and Aghaiae-Khafri (2014) (10) , and a number of other researchers (2,4,12,13) . The 2-turn, 3-turn, ..., and n-turn ECMAE dies with geometries of S -, U -, T -, X -, W -types could be classified as multiple angle dies (1,3,6,7) .…”

Predicting the shape formation of hollow parts with a flange in the process of combined radial-reverse extrusion

“…Based on the analysis of literary data of recent years, it is possible to outline a range of major issues in the study of basic cold extrusion schemes and combination extrusion processes with several degrees of metal flow [9][10][11][12][13][14][15][16][17][18][19].…”

“…This allows the production of articles with the lowest energy and labor-intensive indicators, the highest metal utilization rate, and high surface quality. Studies in recent years relate to the traditional methods of cold extrusion (longitudinal and transverse) [9,10] and the processes of combined extrusion with several degrees of freedom of metal flow [11]. At the same time, the analysis of force and deformation regimes and the shape formation of parts is often performed on the basis of finite-element modeling and experimentally.…”