scholarly journals Evolution of the Material Microstructures and Mechanical Properties of AA1100 Aluminum Alloy within a Complex Porthole Die during Extrusion

Materials ◽  
2018 ◽  
Vol 12 (1) ◽  
pp. 16 ◽  
Author(s):  
Ding Tang ◽  
Wenli Fang ◽  
Xiaohui Fan ◽  
Tianxia Zou ◽  
Zihan Li ◽  
...  
Keyword(s):  
Plastic Deformation ◽  
Electron Backscatter Diffraction ◽  
Flow Line ◽  
Mechanical Tests ◽  
Element Analysis ◽  
Line Model ◽  
Porthole Die ◽  
Final Property ◽  
Backscatter Diffraction ◽  
Aa1100 Aluminum Alloy

Microchannel tube (MCT) is widely employed in industry due to its excellent efficiency in heat transfer. An MCT is commonly produced through extrusion within a porthole die, where severe plastic deformation is inevitably involved. Moreover, the plastic deformation, which dramatically affects the final property of the MCT, varies significantly from location to location. In order to understand the development of the microstructure and its effect on the final property of the MCT, the viscoplastic self-consistent (VPSC) model, together with the finite element analysis and the flow line model, is employed in the current study. The flow line model is used to reproduce the local velocity gradient within the complex porthole die, while VPSC model is employed to predict the evolution of the microstructure accordingly. In addition, electron backscatter diffraction (EBSD) measurement and mechanical tests are used to characterize the evolution of the microstructure and the property of the MCT. The simulation results agree well with the corresponding experimental ones. The influence of the material’s flow line on the evolution of the orientation and morphology of the grains, and the property of the produced MCT are discussed in detail.

scholarly journals Evolution of the Material Microstructures and Mechanical Properties of A1100 Aluminum Alloy within a Complex Porthole Die during Extrusion

2018 ◽  
Author(s):  
Ding Tang ◽  
Wenli Fang ◽  
Xiaohui Fan ◽  
Tianxia Zou ◽  
Zihan Li ◽  
...  
Keyword(s):  
Plastic Deformation ◽  
Electron Backscatter Diffraction ◽  
Flow Line ◽  
Mechanical Tests ◽  
Element Analysis ◽  
Line Model ◽  
Porthole Die ◽  
Final Property ◽  
Channel Tube ◽  
Backscatter Diffraction

Micro channel tube (MCT) is widely employed in industry due to its excellent efficiency in heat transfer. An MCT is commonly produced through extrusion within a porthole die, where severe plastic deformation is inevitably involved. Moreover, the plastic deformation, which dramatically affects the final property of the MCT, varies significantly from location to location. In order to understand the development of the microstructure and its effect on the final property of the MCT, the viscoplastic self-consistent (VPSC) model, together with the finite element analysis and the flow line model, is employed in the current study. The flow line model is used to reproduce the local velocity gradient within the complex porthole die, while VPSC model is employed to predict the evolution of the microstructure accordingly. In addition, electron backscatter diffraction (EBSD) measurement and mechanical tests are used to characterize the evolution of the microstructure and the property of the MCT. The simulation results agree well with the corresponding experimental ones. The influence of the material’s flow line on the evolution of the orientation and morphology of the grains, and the property of the produced MCT are discussed in detail.

scholarly journals A New Experimental Method for Determining the Thickness of Thin Surface Layers of Intensive Plastic Deformation Using Electron Backscatter Diffraction Data

Symmetry ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 677
Author(s):  
Alexander Smirnov ◽  
Evgeniya Smirnova ◽  
Sergey Alexandrov
Keyword(s):  
Plastic Deformation ◽  
Electron Backscatter Diffraction ◽  
Thin Layers ◽  
New Method ◽  
Metallic Materials ◽  
Surface Layers ◽  
Kernel Average Misorientation ◽  
Electron Backscatter ◽  
Properties Of Materials ◽  
Backscatter Diffraction

It is, in general, essential to investigate correlations between the microstructure and properties of materials. Plastic deformation often localizes within thin layers. As a result, many material properties within such layers are very different from the properties in bulk. The present paper proposes a new method for determining the thickness of a thin surface layer of intensive plastic deformation in metallic materials. For various types of materials, such layers are often generated near frictional interfaces. The method is based on data obtained by Electron Backscatter Diffraction. The results obtained are compared with those obtained by an alternative method based on microhardness measurements. The new method allows for determining the layer thickness of several microns in specimens after grinding. In contrast, the measurement of microhardness does not reveal the presence of this layer. The grain-based and kernel-based types of algorithms are also adopted for determining the thickness of the layer. Data processed by the strain contouring and kernel average misorientation algorithms are given to illustrate this method. It is shown that these algorithms do not clearly detect the boundary between the layer of intensive plastic deformation and the bulk. As a result, these algorithms are unable to determine the thickness of the layer with high accuracy.

scholarly journals Graphite Morphology's Influence on Shot Peening Results in Cast Irons

2013 ◽  
Vol 768-769 ◽  
pp. 542-549 ◽  
Author(s):  
Matthias Lundberg ◽  
Ru Lin Peng ◽  
Maqsood Ahmad ◽  
Daniel Bäckström ◽  
Taina Vuoristo ◽  
...  
Keyword(s):  
Plastic Deformation ◽  
Cast Iron ◽  
Shot Peening ◽  
Electron Backscatter Diffraction ◽  
Plastic Deformation Zone ◽  
Cast Irons ◽  
The Matrix ◽  
Electron Imaging ◽  
Backscatter Diffraction ◽  
Graphite Inclusions

The different shot peening responds of a grey cast iron (GI) with its flake graphite and a compacted cast iron (CGI) with its vermicular graphite was analyzed and compared in this paper. For peening using identical parameters, CGI showed a larger plastic deformation zone with higher subsurface compressive stresses than GI. Electron backscatter diffraction (EBSD) mapping and backscatter electron imaging revealed that plastic deformation of the matrix near graphite inclusions is affected by the size and geometry of the graphite. The different behaviors of graphite are explained by their capability to damp mechanical force but at the same time to cause stress concentration in the matrix. The better shot peening results for CGI may be attributed to a lower damping effect of its graphite inclusions and capability of the matrix for larger plastic deformation.

How low can you go? - Extending downwards the limits of plastic deformation in pyrite

2009 ◽  
Vol 73 (6) ◽  
pp. 895-913 ◽  
Author(s):  
C. D. Barrie ◽  
A. P. Boyle ◽  
M. Salter
Keyword(s):  
Plastic Deformation ◽  
Electron Backscatter Diffraction ◽  
Ore Deposits ◽  
Deformation Mechanisms ◽  
Dislocation Glide ◽  
Orientation Contrast ◽  
Brittle Ductile Transition ◽  
History Of ◽  
Diffusive Processes ◽  
Backscatter Diffraction

AbstractUnderstanding the deformation mechanisms that may operate in pyrite (FeS2) across a range ofP-Tconditions is important in deciphering the history of deformed ore deposits. Pyrite has frequently been considered a hard mineral, which deforms by cataclastic flow or diffusive processes, if at all, at temperatures <425°C. However, utilizing SEM-based orientation-contrast (OC) imaging and electron-backscatter diffraction (EBSD) techniques, plastic deformation can now be readily identified within pyrite grains. In this study, a series of pyrite-rich polymetallic ore deposits, deformed at low temperature metamorphic conditions (∼200—420°C), have been investigated. Results indicate that pyrite grains in all the ore deposits preserve internal lattice ‘distortion’ or ‘bending’ and therefore plastic deformation mechanisms have operated. Many pyrite grains in the ore deposits also contain low-angle (∼2°) sub-grain boundaries or ‘dislocation walls', indicating that both dislocation glide and creep have been the dominant deformation mechanisms at peak metamorphic conditions within the pyrite grains. These results suggest that the brittle-ductile transition in pyrite occurs at temperatures potentially as low as ∼200°C, far lower than implied from previous studies or the current pyrite deformation-mechanism map.

scholarly journals Effect of Incremental Shrinking Process on Mechanical Properties and Microstructure of Alloy through Electron Backscatter Diffraction Analysis

2021 ◽  
Vol 2083 (2) ◽  
pp. 022079
Author(s):  
Zhengwei Gu ◽  
Yusheng Li ◽  
Ziming Tang ◽  
Ge Yu
Keyword(s):  
Mechanical Properties ◽  
Aluminum Alloy ◽  
Electron Backscatter Diffraction ◽  
Mechanical Tests ◽  
Mechanical Anisotropy ◽  
Forming Process ◽  
Ebsd Data ◽  
Electron Backscatter ◽  
Shrinking Process ◽  
Backscatter Diffraction

Abstract In recent years, the incremental shrinking process has been widely used in the forming process of aluminum alloy components for the railway vehicles. The effect of the incremental shrinking process on the performance and microstructure of 6082-T6 aluminum alloy was investigated through mechanical tests and electron backscatter diffraction (EBSD) analysis. The tensile test specimens prepared in different rolling orientations (0˚,45˚and 90˚) along the original and deformed sheets exhibited the mechanical anisotropy. After the incremental shrinking process, the average microhardness, tensile strength, and yield strength of this alloy were respectively increased by nearly 8.78%,2.26%,2.72%, while the Elongation was decreased by almost 31.67%. By analyzing the EBSD data, the strength of the material is increased by the incremental shrinking process and its mechanical anisotropy is improved, whereas its plasticity is greatly deteriorated.

scholarly journals Understanding the Machinability of Austempered Ductile Iron (ADI)

2018 ◽  
Vol 925 ◽  
pp. 311-317 ◽  
Author(s):  
Dika Handayani ◽  
Robert C. Voigt ◽  
Kathy Hayrynen
Keyword(s):  
Plastic Deformation ◽  
Martensitic Transformation ◽  
Severe Plastic Deformation ◽  
Ductile Iron ◽  
Cutting Tool ◽  
Electron Backscatter Diffraction ◽  
Austempered Ductile Iron ◽  
Finish Machining ◽  
Electron Backscatter ◽  
Backscatter Diffraction

Guidelines for production milling, turning and drilling of the standard grades of austempered ductile irons (ADI) have been established. Electron Backscatter Diffraction (EBSD) characterization has clearly shown that severe plastic deformation in the machining-affected-zone, ahead of and beneath the cutting tool, will cause strain-induced martensitic transformation of the austenite in the ausferrite structure that inhibits machinability. This phenomenon is particularly of concern during finish machining where small depths of cut are strongly influenced by surface martensite from prior machining passes.

Observations of Dislocation Structure in AA 7050 by EBSD

2011 ◽  
Vol 702-703 ◽  
pp. 493-498 ◽  
Author(s):  
C.C. Merriman ◽  
David P. Field
Keyword(s):  
Plastic Deformation ◽  
Aluminum Alloy ◽  
Dislocation Density ◽  
Cell Walls ◽  
Electron Backscatter Diffraction ◽  
Geometrically Necessary Dislocation ◽  
Dislocation Densities ◽  
Electron Backscatter ◽  
Dislocation Density Tensor ◽  
Backscatter Diffraction

During and after plastic deformation of metals, dislocations tend to evolve into generally well-defined structures that may include tangles, bands, cell walls, and various additional features. Observation of these structures by electron backscatter diffraction is only accomplished by analysis of changes in orientation from one position to the next. Excess (or geometrically necessary) dislocation densities can be inferred from 2D measurements or obtained directly from 3D measurements as indicated by Nye’s dislocation density tensor. Evolution of excess dislocation densities was measured for a split channel die specimen of aluminum alloy 7050 in the T7451 temper. Densities evolved by a factor or 1.6 for compressive deformations of 15%.

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