Erratum to “Accurate electron channeling contrast analysis of dislocations in fine grained bulk materials” [Scripta Mater. 84–85 (2014) 11–14]

2014 ◽  
Vol 89 ◽  
pp. 77-78 ◽  
Author(s):  
H. Mansour ◽  
J. Guyon ◽  
M.A. Crimp ◽  
N. Gey ◽  
B. Beausir ◽  
...  
Keyword(s):  
Bulk Materials ◽  
Electron Channeling ◽  
Fine Grained ◽  
Contrast Analysis ◽  
Scripta Mater

scholarly journals Accurate electron channeling contrast analysis of dislocations in fine grained bulk materials

2014 ◽  
Vol 84-85 ◽  
pp. 11-14 ◽  
Author(s):  
H. Mansour ◽  
J. Guyon ◽  
M.A. Crimp ◽  
N. Gey ◽  
B. Beausir ◽  
...  
Keyword(s):  
Bulk Materials ◽  
Electron Channeling ◽  
Fine Grained ◽  
Contrast Analysis

Microcrack Nucleation and Crack Propagation in Equiaxed γ TiAl

2002 ◽  
Vol 753 ◽  
Author(s):  
Martin A. Crimp ◽  
Boon-Chi Ng ◽  
Benjamin A. Simkin ◽  
Thomas R. Bieler
Keyword(s):  
Ex Situ ◽  
Contrast Imaging ◽  
Active Deformation ◽  
Electron Channeling ◽  
Microcrack Initiation ◽  
Grain Orientations ◽  
Contrast Analysis ◽  
Defect Imaging

ABSTRACTTo gain a better understanding of the ductility limitations in TiAl alloys, the mechanisms involved in deformation strain transfer and/or microcrack initiation at grain boundaries have been examined in an equiaxed near-γ alloy. These studies have been carried out on both in-situ and ex-situ deformed bulk samples using scanning electron microscopy (SEM) techniques for both orientation analysis and deformation defect imaging. Selected area electron channeling patterns (SACPs) have allowed determination of grain orientations, eliminating ambiguity between the a and c axes. Deformation twins and dislocations have been imaged in the bulk samples using electron channeling contrast imaging (ECCI). A combination of ECCI contrast analysis and trace analysis based on orientations determined from SACP has allowed identification of the active deformation systems. Microcracks have been found to initiate at γ-γ boundaries as a result of an inability to adequately transfer twin strain from grain to grain. Once initiated, cracks propagate through cleavage and re-nucleation of grain boundary microcracks in front of the advancing crack. A geometric based predictive factor has been developed that accounts for microcrack initiation at γ-γ boundaries based in deformation twinning and strain accommodation by ordinary dislocations.

BKD in the SEM: Toward a smaller information volume

1994 ◽  
Vol 52 ◽  
pp. 606-607 ◽  
Author(s):  
K. Troost ◽  
J.-D. Kamminga
Keyword(s):  
Texture Analysis ◽  
Beam Current ◽  
Electron Gun ◽  
Lateral Resolution ◽  
Bulk Materials ◽  
Interaction Volume ◽  
Fine Grained ◽  
Information Depth ◽  
Lower Beam ◽  
Optical Brightness

Upto now, the recording of backscatter Kikuchi diffraction (BKD) patterns (also called electron backscattering patterns, EBSP) for microscale texture analysis is mostly performed at high primary beam voltages U > 20 kV using an SEM with a tungsten or LaB6 electron gun. Under these circumstances, a lateral resolution of 0.2-0.5 μm has been reported. However, the texture analysis of fine-grained bulk materials or vacuum-deposited thin metallic layers as used in the IC-industry requires a higher spatial resolution. A fieldemission electron gun (FEG) with a much higher electron-optical brightness can deliver the 1-nA beam current needed for EBSP recording in a spot of about 10 nm, enabling a lateral resolution of 20×80 nm3 and an information depth of 10 nm at 20 kV. In Ref. 2, the possibility of using lower beam voltages to obtain an even higher resolution is mentioned. Monte Carlo simulations indeed show that the interaction volume decreases at least linearly with decreasing U.

Rotary-Die Equal Channel Angular Pressing Method for Light Metals

2010 ◽  
Vol 638-642 ◽  
pp. 1614-1617
Author(s):  
Akira Watazu ◽  
Ichinori Shigematsu ◽  
Masataka Hakamada ◽  
Kazutaka Suzuki ◽  
Xin Sheng Huang ◽  
...  
Keyword(s):  
Magnesium Alloys ◽  
Aluminium Alloys ◽  
Light Metals ◽  
Bulk Materials ◽  
Ecap Processing ◽  
Pressing Method ◽  
Fine Grained ◽  
Angular Pressing ◽  
Ecap Process ◽  
Process Method

A new ECAP process method called rotary-die ECAP (RD-ECAP) was developed to form fine-grained bulk materials such as aluminium alloys, magnesium alloys, aluminium composites, and titanium, all of which can be processed under conditions of 573-773K, at an approximately 0.9-2.4 mm/s punch speed of 300MPa or lower. By the RD-ECAP method, ECAP processing of up to 2 passes can be done without sample removal and samples processed over 30 cycles were obtained.

scholarly journals Accurate electron channeling contrast analysis of a low angle sub-grain boundary

2015 ◽  
Vol 109 ◽  
pp. 76-79 ◽  
Author(s):  
H. Mansour ◽  
M.A. Crimp ◽  
N. Gey ◽  
N. Maloufi
Keyword(s):  
Grain Boundary ◽  
Electron Channeling ◽  
Contrast Analysis

scholarly journals Thermoelectric Properties of Fine-Grained PbTe Bulk Materials Fabricated by Cryomilling and Spark Plasma Sintering

2011 ◽  
Vol 52 (4) ◽  
pp. 795-801 ◽  
Author(s):  
Chia-Hung Kuo ◽  
Hsiu-Shan Chien ◽  
Chii-Shyang Hwang ◽  
Ya-Wen Chou ◽  
Ming-Shan Jeng ◽  
...  
Keyword(s):  
Spark Plasma Sintering ◽  
Thermoelectric Properties ◽  
Bulk Materials ◽  
Fine Grained ◽  
Plasma Sintering ◽  
Spark Plasma

scholarly journals Analysis of deformation characteristics of Asymmetric Gradient Extrusion in preparing ultra-fine grained bulk materials

2021 ◽  
Author(s):  
Junkai Fan ◽  
Chengpeng Wang ◽  
Wu Zhao ◽  
Wei Liu
Keyword(s):  
Strain Distribution ◽  
Extrusion Direction ◽  
Deformation Characteristics ◽  
Bulk Materials ◽  
Element Analysis ◽  
Line Field ◽  
Fine Grained ◽  
Accumulated Strain ◽  
Novel Method ◽  
Inclined Planes

Abstract A novel method to prepare ultra-fine grained bulk materials, which is named Asymmetric Gradient Extrusion (AGE), is proposed in this article. In AGE, the cross section of extrusion channel is rectangle and two inclined planes are stagger arranged along extrusion direction. To realize repeating extrusion, the thickness of workpiece is restricted to equal the width of channel’s outlet. The deformation characteristics of AGE was first theoretically analyzed by slip line field. Then, these results were verified and supplemented by finite element analysis. The results reveal that deformation characteristics of workpiece in channel is largely related to the two inclined planes. Two independent deformation zones (TIDZ) can be formed with increasing distance between the two inclined planes. In addition, the accumulated strain generated in the TIDZ is complementary in value. Furthermore, the shearing effects of workpiece subjected in one pass extrusion has been improved. A more uniform strain distribution and higher shearing effect can be generated in AGE, which make it as a very promising method to produce ultra-fine grained bulk materials.

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