An upper-bound analysis for equal-channel angular extrusion

2005 ◽  
Vol 168 (1) ◽  
pp. 137-146 ◽  
Author(s):  
B.S. Altan ◽  
G. Purcek ◽  
I. Miskioglu
Keyword(s):  
Upper Bound ◽  
Equal Channel Angular Extrusion ◽  
Upper Bound Analysis ◽  
Angular Extrusion ◽  
Bound Analysis

Upper-Bound Analysis for Change-Channel Angular Extrusion

2009 ◽  
Vol 610-613 ◽  
pp. 838-843
Author(s):  
Tian Mo Liu ◽  
Yu Liu ◽  
Li Wei Lu ◽  
Fu Sheng Pan
Keyword(s):  
Upper Bound ◽  
Deformation Process ◽  
Extrusion Process ◽  
Extrusion Force ◽  
Upper Bound Theorem ◽  
Upper Bound Analysis ◽  
Outer Corner ◽  
Angular Extrusion ◽  
Deformation Patterns ◽  
Bound Analysis

Deformation of the material during 90° change-channel angular extrusion (CCAE) process is analyzed using upper-bound theorem. The mathematical model was established which includes the effect of friction between the sample and inner surface of the die, radius of inner and outer corner of the die, and the dead metal zone on the deformation patterns during change-channel angular extrusion deformation process. The model of parameters is explored in relation to the deformation of the material during the change-channel angular extrusion process. Results showed that the extrusion force increased with the increase of extrusion ratio (a2/b2), friction factor m, out corner and the reduce of inner corner. Further directions for progress in upper-bound analysis in change-channel angular extrusion deformation process are outlined.

Upper Bound Analysis of the ECAE Process by Considering Strain Hardening Materials and Three-Dimensional Rectangular Dies

2008 ◽  
Vol 130 (5) ◽  
Author(s):  
R. Luri ◽  
C. J. Luis Pérez
Keyword(s):  
Strain Hardening ◽  
Cross Section ◽  
Upper Bound ◽  
Equal Channel Angular Extrusion ◽  
Rectangular Cross Section ◽  
Three Dimensional ◽  
Plastic Deformations ◽  
Material Parameters ◽  
Upper Bound Analysis ◽  
Bound Analysis

Equal channel angular extrusion (ECAE) or pressing is a process used to introduce severe plastic deformations to processed materials with the aim of improving their mechanical properties by reducing the grain size. At present, there are no analytical studies that have considered strain hardening materials in order to determine the required force to carry out the process. All the existing papers have only considered nonstrain hardening materials. Furthermore, all those studies have been done by considering plane strain conditions. In this work, an upper bound analysis of the required force for performing the ECAE process is made by considering a full three-dimensional geometry with a rectangular cross section. From this analysis, the influence of the geometric and the material parameters is studied by considering both friction and strain hardening materials. By using the upper bound method, an analytical formulation was obtained and the influence of all the parameters was determined. With this work, it is possible to have a wider knowledge of the influence of the main affecting parameters in the ECAE process and to optimize them.

Upper-Bound Analysis

Metal Forming ◽  
2012 ◽  
pp. 110-127
Author(s):  
William F. Hosford ◽  
Robert M. Caddell
Keyword(s):  
Upper Bound ◽  
Upper Bound Analysis ◽  
Bound Analysis
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