scholarly journals Deformation Behavior of Al/Cu Clad Composite During Twist Channel Angular Pressing

Materials ◽  
2020 ◽  
Vol 13 (18) ◽  
pp. 4047 ◽  
Author(s):  
Radim Kocich
Keyword(s):  
Residual Stress ◽  
Cross Section ◽  
Deformation Behavior ◽  
Effective Strain ◽  
Metallic Materials ◽  
Double Pass ◽  
Angular Pressing ◽  
Punch Load ◽  
First Pass ◽  
Al Matrix

The research and development of modern metallic materials goes hand in hand with increasing their lifetime via optimized deformation processing. The presented work deals with preparation of an Al/Cu clad composite with implemented reinforcing Cu wires by the method of twist channel angular pressing (TCAP). Single and double pass extrusion of the clad composite was simulated numerically and carried out experimentally. This work is unique as no such study has been presented so far. Detailed monitoring of the deformation behavior during both the passes was enabled by superimposed grids and sensors. Both the sets of results revealed that already the single pass imparted significant effective strain (higher than e.g., conventional equal channel angular pressing (ECAP)), especially to the Al matrix, and resulted in notable deformation strengthening of both the Al and Cu composite components, which was confirmed by the increased punch load and decreased plastic flow velocity (second pass compared to first pass). Processing via the second pass also resulted in homogenization of the imposed strain and residual stress across the composite cross-section. However, the investigated parameters featured slight variations in dependence on the monitored location across the cross-section.

Three Dimensional Numerical Investigation of Equal Channel Multi-Angular Pressing

2006 ◽  
Vol 503-504 ◽  
pp. 931-936
Author(s):  
Quang Pham ◽  
Seung Chae Yoon ◽  
Sun Ig Hong ◽  
Hyoung Seop Kim
Keyword(s):  
Plastic Deformation ◽  
Deformation Behavior ◽  
Effective Strain ◽  
Three Dimensional ◽  
Workpiece Material ◽  
Angular Pressing ◽  
Commercial Code ◽  
Plastic Deformation Behavior ◽  
Central Regions ◽  
Global Deformation

Plastic deformation behavior during equal channel multi-angular pressing (ECMAP) was analyzed using the three dimensional finite volume method of the commercial code MSC.Superforge. In order to understand local and global deformation characteristics, effective strain and pressing load histories were investigated. The predicted plastic deformation behavior of the workpiece material during ECMAP of route A, route B and route C with a theoretical total strain of ~2.2 upon a single pass at three different friction factors (m=0, 0.1 and 0.2) was compared. The predicted strain results show different values in outside and similar values in central regions of the processed workpieces with different friction and forming routes. The pressing loads are higher under higher friction condition, showing almost no difference with three different pressing routes.

Development of structure and properties in bimetallic Al/Cu sandwich composite during cumulative severe plastic deformation

2021 ◽  
pp. 109963622199388
Author(s):  
Radim Kocich ◽  
Lenka Kunčická
Keyword(s):  
Cross Sections ◽  
Deformation Behaviour ◽  
Effective Strain ◽  
Ct Scanning ◽  
Sandwich Composite ◽  
Homogeneous Distribution ◽  
The Finite Element Method ◽  
Double Pass ◽  
Angular Pressing ◽  
Average Grain Size

Development of modern materials is non-negligibly connected with enhancement of their mechanical and utility properties, which can advantageously be performed via optimized deformation processing. The study presents preparation of Al/Cu sandwich composite, reinforced with Cuwires, by the twist channel angular pressing (TCAP) method. Extrusion of the sandwich composite via single and double pass TCAP was simulated using the finite element method, and performed experimentally. The predicted deformation behaviour was verified by 3 D Micro-CT scanning, as well as detailed microstructure observations. The results showed that already the single TCAP resulted in substantial deformation strengthening of both the component metals, and the effective strain imposed within the Alsheath reached the value of 5 after the second pass. The Alsheath also featured homogeneous distribution of the lowest absolute values of residual stress, and the smallest average grain size of 1.66 µm. The Cu grains within both the composites were also significantly refined, to almost 3 µm after the second pass. Nevertheless, the observed parameters featured slight variations across the composites’ cross-sections, which can be attributed to the plastic flow behaviour phenomena. The severe imposed shear strain also resulted in increase in microhardness and imparted changes in the thermal conductivity.

Observation of secondary slip systems in tungsten bicrystals

1984 ◽  
Vol 42 ◽  
pp. 478-479
Author(s):  
J. R. Fekete ◽  
R. Gibala
Keyword(s):  
Stress Field ◽  
Grain Boundaries ◽  
Deformation Behavior ◽  
Stress Axis ◽  
Polycrystalline Materials ◽  
Slip Systems ◽  
Metallic Materials ◽  
Twist Boundary ◽  
Secondary Slip ◽  
Plane Normal

The deformation behavior of metallic materials is modified by the presence of grain boundaries. When polycrystalline materials are deformed, additional stresses over and above those externally imposed on the material are induced. These stresses result from the constraint of the grain boundaries on the deformation of incompatible grains. This incompatibility can be elastic or plastic in nature. One of the mechanisms by which these stresses can be relieved is the activation of secondary slip systems. Secondary slip systems have been shown to relieve elastic and plastic compatibility stresses. The deformation of tungsten bicrystals is interesting, due to the elastic isotropy of the material, which implies that the entire compatibility stress field will exist due to plastic incompatibility. The work described here shows TEM observations of the activation of secondary slip in tungsten bicrystals with a [110] twist boundary oriented with the plane normal parallel to the stress axis.

scholarly journals Experimental and Numerical Investigation of the ECAP Processed Copper: Microstructural Evolution, Crystallographic Texture and Hardness Homogeneity

Metals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 607
Author(s):  
A. I. Alateyah ◽  
Mohamed M. Z. Ahmed ◽  
Yasser Zedan ◽  
H. Abd El-Hafez ◽  
Majed O. Alawad ◽  
...  
Keyword(s):  
Grain Size ◽  
Equal Channel Angular Pressing ◽  
Cross Section ◽  
Room Temperature ◽  
Pure Copper ◽  
High Density ◽  
Ecap Processing ◽  
Heterogeneous Distribution ◽  
Angular Pressing ◽  
Average Grain Size

The current study presents a detailed investigation for the equal channel angular pressing of pure copper through two regimes. The first was equal channel angular pressing (ECAP) processing at room temperature and the second was ECAP processing at 200 °C for up to 4-passes of route Bc. The grain structure and texture was investigated using electron back scattering diffraction (EBSD) across the whole sample cross-section and also the hardness and the tensile properties. The microstructure obtained after 1-pass at room temperature revealed finer equiaxed grains of about 3.89 µm down to submicrons with a high density of twin compared to the starting material. Additionally, a notable increase in the low angle grain boundaries (LAGBs) density was observed. This microstructure was found to be homogenous through the sample cross section. Further straining up to 2-passes showed a significant reduction of the average grain size to 2.97 µm with observable heterogeneous distribution of grains size. On the other hand, increasing the strain up to 4-passes enhanced the homogeneity of grain size distribution. The texture after 4-passes resembled the simple shear texture with about 7 times random. Conducting the ECAP processing at 200 °C resulted in a severely deformed microstructure with the highest fraction of submicron grains and high density of substructures was also observed. ECAP processing through 4-passes at room temperature experienced a significant increase in both hardness and tensile strength up to 180% and 124%, respectively.

Numerical Simulation of the Effects of Preheating on Electron Beam Additive Manufactured Ti-6Al-4V Build Plate

2016 ◽  
Vol 879 ◽  
pp. 274-278 ◽  
Author(s):  
Jun Cao ◽  
Philip Nash
Keyword(s):  
Numerical Simulation ◽  
Residual Stress ◽  
Finite Element ◽  
Electron Beam ◽  
Cross Section ◽  
Element Model ◽  
Normal Direction ◽  
Thermal Residual Stresses ◽  
Longitudinal Residual Stress ◽  
Middle Cross Section

In an earlier study, a 3-D thermomechanical coupled finite element model was built and experimentally validated to investigate the evolution of the thermal residual stresses and distortions in electron beam additive manufactured Ti-6Al-4V build plates. In this study, an investigation using this robust and accurate model was focused on an efficient preheating method, in which the electron beam quickly scanned across the substrate to preheat the build plate prior to the deposition. Various preheat times, beam powers, scan rates, scanning paths and cooling times (between the end of current preheat scan/deposition layer and the beginning of the next preheat scan/deposition layer) were examined, and the maximum distortion along the centerline of the substrate and the maximum longitudinal residual stress along the normal direction on the middle cross-section of the build plate were quantitatively compared. The results show that increasing preheat times and beam powers could effectively reduce both distortion and residual stress for multiple layers/passes components.

Prediction for Post-Forming Spring Back of CICC in the Superconducting Tokamak Fusion Device via Virtual Manufacturing

2000 ◽  
Author(s):  
Yeong Sung Suh ◽  
Jong Sung Ahn ◽  
Sun Woong Choi ◽  
Hyun Ki Park ◽  
Yong Jin Kim ◽  
...  
Keyword(s):  
Residual Stress ◽  
Cross Section ◽  
Virtual Manufacturing ◽  
Von Mises Stress ◽  
Radius Of Curvature ◽  
Spring Back ◽  
Cross Sectional ◽  
Fusion Device ◽  
Roll Bending ◽  
Superconducting Tokamak

Abstract To construct the CICC for the superconducting Tokamak fusion device, the 3-roll bending, that inherently has a difficulty to form the coil with accurate radius of curvature, is used for continuous winding. In order to obtain precise dimension, a trial-an-error operation is inevitable. To reduce the effort of tryout, a relation between travel of the bending roller and spring back displacement was obtained via virtual manufacturing. The radius of CICC after forming was expressed as a function of the bend-roll travel. Next, the variation of the CICC cross-section (reduction of the conduit cross-section) was investigated during the first turn and during conduit bending with largest curvature. With largest curvature, the cross-sectional area was not much reduced. Finally, the residual stress on the CICC before roll bending was measured in order to examine the influence of the original residual stress on the final deformation behavior. The principal stress and von Mises stress were measured at the surface of CICC using specially designed strain gauge. The measured values were considered in the virtual forming. The results indicate that the residual stresses generated during the fabrication of the CICC (before coiling) do not have much influence on the final stress state.

Study of the Titanium Alloy Deformation Behavior in Equal Channel Angular Extrusion

2007 ◽  
Vol 345-346 ◽  
pp. 177-180 ◽  
Author(s):  
Dyi Cheng Chen ◽  
Yi Ju Li ◽  
Gow Yi Tzou
Keyword(s):  
Plastic Deformation ◽  
Titanium Alloy ◽  
Deformation Behavior ◽  
Equal Channel Angular Extrusion ◽  
Effective Strain ◽  
Processing Conditions ◽  
Rigid Plastic ◽  
Die Geometry ◽  
Extrusion Processing ◽  
Plastic Deformation Behavior

The shear plastic deformation behavior of a material during equal channel angular (ECA) extrusion is governed primarily by the die geometry, the material properties, and the processing conditions. Using commercial DEFORMTM 2D rigid-plastic finite element code, this study investigates the plastic deformation behavior of Ti-6Al-4V titanium alloy during 1- and 2-turn ECA extrusion processing in dies containing right-angle turns. The simulations investigate the distributions of the billet mesh, effective stress and effective strain under various processing conditions. The respective influences of the channel curvatures in the inner and outer regions of the channel corner are systematically examined. The numerical results provide valuable insights into the shear plastic deformation behavior of Ti-6Al-4V titanium alloy during ECA extrusion.

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