scholarly journals Characterization of microstructure and crack propagation in alumina using orientation imaging microscopy (OIM). December 1996

1996 ◽  
Author(s):  
S.J. Glass ◽  
J.R. Michael ◽  
M.J. Readey ◽  
S.I. Wright ◽  
D.P. Field
Keyword(s):  
Crack Propagation ◽  
Orientation Imaging Microscopy ◽  
Orientation Imaging

scholarly journals Characterization of Microstructure and Crack Propagation in Alumina Using Orientation Imaging Microscopy (OIM)

1998 ◽  
pp. 803-813 ◽  
Author(s):  
S. Jill Glass ◽  
Joseph R. Michael ◽  
Michael J. Readey ◽  
Stuart I. Wright ◽  
David P. Field
Keyword(s):  
Crack Propagation ◽  
Orientation Imaging Microscopy ◽  
Orientation Imaging

Spatially Resolved Characterization of Microstructure, Defects and Tilts in GaN Layers Grown on Si(111) Substrates by Maskless Cantilever Epitaxy

2006 ◽  
Vol 934 ◽  
Author(s):  
Rozaliya Barabash ◽  
C. Roder ◽  
G. E. Ice ◽  
S. Einfeldt ◽  
J. D. Budai ◽  
...  
Keyword(s):  
Orientation Imaging Microscopy ◽  
Growth Conditions ◽  
Threading Dislocations ◽  
Misfit Dislocations ◽  
X Ray ◽  
Orientation Imaging ◽  
Spatially Resolved ◽  
Dislocation Arrays ◽  
Tilt Boundaries

ABSTRACTThe spatially resolved distribution of strain, misfit and threading dislocations, and crystallographic orientation in uncoalesced GaN layers grown on Si(111) substrates by maskless cantilever epitaxy was studied by white-beam Laue x-ray microdiffraction, scanning electron microscopy, and orientation imaging microscopy. Tilt boundaries formed at the column/wing interface with the misorientation strongly depending on the growth conditions. A depth-dependent deviatoric strain gradient is found in the GaN. Types and density of misfit dislocations as well as their arrangement within different dislocation arrays was quantified. The results are discussed with respect to the miscut of the Si(111) surface and misfit dislocations formed at the interface.

Recovery and Recrystallization Study after Low Deformation Amount by Cold Rolling in an IF-Ti Steel

2004 ◽  
Vol 467-470 ◽  
pp. 183-188 ◽  
Author(s):  
Amel Samet-Meziou ◽  
Anne Laure Etter ◽  
Thierry Baudin ◽  
Richard Penelle
Keyword(s):  
Cold Rolling ◽  
Boundary Migration ◽  
Orientation Imaging Microscopy ◽  
Continuous Growth ◽  
Orientation Imaging ◽  
Transmission Electron ◽  
Deformation Amount ◽  
Deformed State ◽  
Electron Back Scattered Diffraction

The first steps of recovery and recrystallization in an IF-Ti steel after 40% cold rolling have been studied using the Electron Back Scattered Diffraction (EBSD), Orientation Imaging Microscopy(™) (OIM) and the Transmission Electron Microscopy (TEM). As it is well known, for low deformation amounts by cold rolling, recrystallization texture exhibits the g fiber (ND // <111>) with a reinforcement of the {111}<110> orientation. In order to understand this {111}<110> development during recrystallization, characterization of the deformed state was performed. Different microstructures were distinguished: lamellar bands for the {111}<112> grains of the g fiber and coarse elongated cells for the {111}<110> orientation that belongs to the a and g fibers. Whatever the initial dislocation structure, the recovery step seems to be characterized by coalescence and growth of existing cells in the recovered matrix. Then nucleus growth seems to occur by sub-boundary migration. The first steps of recrystallization mainly take place by continuous growth of subgrains including or not the bulging of grain boundaries.

scholarly journals Mapping the Mesoscale Interface Structure in Polycrystalline Materials

1999 ◽  
Vol 5 (S2) ◽  
pp. 260-261
Author(s):  
C. T. Wu ◽  
B. L. Adams ◽  
C. L. Bauer ◽  
D. Casasent ◽  
A. Morawiec ◽  
...  
Keyword(s):  
Orientation Imaging Microscopy ◽  
Polycrystalline Materials ◽  
Section Plane ◽  
Grid Spacing ◽  
New Approach ◽  
Orientation Imaging ◽  
Mapping System ◽  
Dimensional Section ◽  
Contrast Image

Using the new method known as Orientation Imaging Microscopy (OIM), characterization of mesoscale aspect of the internal structure of polycrystalline materials in the two-dimensional section plane has become routine. However, in some applications which primarily focus either on the characterization of interface types or on their connectivity, OIM is rather inefficient since only the scan points that lie adjacent to the interfaces are used to determine interface character. When the OIM grid spacing is dictated by the precision with which the interfacial in-plane inclination must be determined in the section plane, the efficiency with which conventional OIM can harvest interfacial data is rather poor.In this paper a new approach and system of microscopy is described, called the Mesoscale Interface Mapping System (MIMS). MIMS overcomes the challenges associated with OIM by directing the beam to the vicinity of interfaces which have been identified by a microstructural contrast image.

In situ observation of orientation changes on metallic surfaces

1995 ◽  
Vol 53 ◽  
pp. 246-247
Author(s):  
H. Weiland ◽  
D.P. Field ◽  
B.L. Adams
Keyword(s):  
Bulk Material ◽  
Orientation Imaging Microscopy ◽  
In Situ Observation ◽  
Metallic Surfaces ◽  
Orientation Imaging ◽  
Diffraction Patterns ◽  
Characterization Of Materials ◽  
Crystalline Aggregates ◽  
Crystallographic Orientations

The characterization of crystalline aggregates by the crystallographic orientations of their grains and subgrains has become a subject of increasing interest. The information obtained is not only used for the characterization of materials, but also more importantly for the determination of properties. To mention only a few, applications have been found in the areas of fracture analysis, recrystallization, and plastic deformation.Most commonly, crystallographic orientations are determined from Backscattered Kikuchi Diffraction (BKD) in the SEM and from Kikuchi patterns obtained by microdiffraction in the TEM. Since the development of fully automatic pattern analysis routines for the BKD, the SEM based techniques currently finds the most applications. In conjunction with computer controlled stage or beam displacements, the technique is known as Orientation Imaging Microscopy (OIM). In this manner, thousands of diffraction patterns are analyzed automatically within a short time. This leads to a statistical description of the distribution of crystallographic orientations, which sufficiently represent the bulk material.

scholarly journals Material parametrization of natural rubber based compound and characterization of crack propagation under consideration of dissipative effects

2021 ◽  
Author(s):  
Dan Pornhagen ◽  
Konrad Schneider ◽  
Markus Stommel
Keyword(s):  
Energy Dissipation ◽  
Crack Propagation ◽  
Natural Rubber ◽  
Experimental Tests ◽  
Material Behavior ◽  
Prony Series ◽  
Material Forces ◽  
Cracking Behavior ◽  
Dissipative Effects

AbstractMost concepts to characterize crack propagation were developed for elastic materials. When applying these methods to elastomers, the question is how the inherent energy dissipation of the material affects the cracking behavior. This contribution presents a numerical analysis of crack growth in natural rubber taking energy dissipation due to the visco-elastic material behavior into account. For this purpose, experimental tests were first carried out under different load conditions to parameterize a Prony series as well as a Bergström–Boyce model with the results. The parameterized Prony series was then used to perform numerical investigations with respect to the cracking behavior. Using the FE-software system ANSYS and the concept of material forces, the influence and proportion of the dissipative components were discussed.

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