scholarly journals Finding and Characterising Active Slip Systems: A Short Review and Tutorial with Automation Tools

Materials ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 407
Author(s):  
James S. K.-L. Gibson ◽  
Risheng Pei ◽  
Martin Heller ◽  
Setareh Medghalchi ◽  
Wei Luo ◽  
...  
Keyword(s):  
A Priori ◽  
Short Review ◽  
Deformation Mechanisms ◽  
Small Scale ◽  
Slip Systems ◽  
Complex Crystal Structure ◽  
Slip Planes ◽  
Automation Tools ◽  
Complex Crystal ◽  
Active Slip

The behaviour of many materials is strongly influenced by the mechanical properties of hard phases, present either from deliberate introduction for reinforcement or as deleterious precipitates. While it is, therefore, self-evident that these phases should be studied, the ability to do so—particularly their plasticity—is hindered by their small sizes and lack of bulk ductility at room temperature. Many researchers have, therefore, turned to small-scale testing in order to suppress brittle fracture and study the deformation mechanisms of complex crystal structures. To characterise the plasticity of a hard and potentially anisotropic crystal, several steps and different nanomechanical testing techniques are involved, in particular nanoindentation and microcompression. The mechanical data can only be interpreted based on imaging and orientation measurements by electron microscopy. Here, we provide a tutorial to guide the collection, analysis, and interpretation of data on plasticity in hard crystals. We provide code collated in our group to help new researchers to analyse their data efficiently from the start. As part of the tutorial, we show how the slip systems and deformation mechanisms in intermetallics such as the Fe7Mo6 μ-phase are discovered, where the large and complex crystal structure precludes determining a priori even the slip planes in these phases. By comparison with other works in the literature, we also aim to identify “best practises” for researchers throughout to aid in the application of the methods to other materials systems.

Dislocation Boundaries and Slip Systems in Uniaxially Deformed Crystals

2001 ◽  
Vol 683 ◽  
Author(s):  
Grethe Winther ◽  
Xiaoxu Huang ◽  
Søren Fæster Nielsen ◽  
John Wert
Keyword(s):  
Single Crystal ◽  
Single Crystals ◽  
Crystal Orientation ◽  
Boundary Plane ◽  
Slip Systems ◽  
Crystal Boundary ◽  
Secondary Slip ◽  
Slip Planes ◽  
Planar Dislocation ◽  
Active Slip

ABSTRACTThe dislocations in the extended planar dislocation boundaries formed during deformation are generated by the active slip systems. Investigation of the boundaries is therefore a tool to obtain information on the active slip systems. Here, the orientation of the dislocation boundaries in uniaxially deformed aluminum poly- and single crystals are compared. It is found that the single crystal boundary planes are consistent with those found in polycrystals, indicating that the active slip systems in single and polycrystals are the same. However, boundaries are closer to the slip planes in the single crystals. This is taken as an indication that the secondary slip systems are more active in the polycrystal. The orientation of the boundary plane varies with the crystal orientation in a way that is consistent with activation of the five most stressed slip systems.

Indentation Techniques for the Study of Deformation Across Grain Boundaries

2003 ◽  
Vol 778 ◽  
Author(s):  
K. A. Nibur ◽  
D. F. Bahr
Keyword(s):  
Grain Boundaries ◽  
Nanocrystalline Materials ◽  
Orientation Imaging Microscopy ◽  
Slip Systems ◽  
Slip Direction ◽  
Force Microscopy ◽  
Orientation Imaging ◽  
Atomic Force ◽  
Slip Planes ◽  
Active Slip

AbstractThe mechanism by which deformation is transferred across grain boundaries and ways in which boundaries of different misorientations impact this process has been studied using indentation testing. This information could be useful in designing texture of nanocrystalline materials to maximize their mechanical properties for specific applications. Atomic force microscopy (AFM) and orientation imaging microscopy (OIM) has been combined to identify slip systems activated around indentations. When indentations are placed near grain boundaries, slip steps can be imaged on both sides of the boundary and the associated slip systems of each grain can be determined. Dislocation pile ups have been observed around indentations near boundaries which do not share a common slip direction with the active slip planes of either grain, and slip steps have been seen to traverse boundaries when these shared slip directions are present.

scholarly journals Prospects of Using Small Scale Testing to Examine Different Deformation Mechanisms in Nanoscale Single Crystals—A Case Study in Mg

Crystals ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 61
Author(s):  
Daniel Kiener ◽  
Jiwon Jeong ◽  
Markus Alfreider ◽  
Ruth Konetschnik ◽  
Sang Ho Oh
Keyword(s):  
Deformation Mechanisms ◽  
Dislocation Slip ◽  
Small Scale ◽  
Crystal Unit Cell ◽  
Slip Planes ◽  
Detailed Assessment ◽  
Stress States ◽  
Electron Microscopes ◽  
Polycrystalline Structures

The advent of miniaturised testing techniques led to excessive studies on size effects in materials. Concomitantly, these techniques also offer the capability to thoroughly examine deformation mechanisms operative in small volumes, in particular when performed in-situ in electron microscopes. This opens the feasibility of a comprehensive assessment of plasticity by spatially arranging samples specifically with respect to the crystal unit cell of interest. In the present manuscript, we will showcase this less commonly utilised aspect of small-scale testing on the case of the hexagonal metal Mg, where, besides dislocation slip on different slip planes, twinning also exists as a possible deformation mechanism. While it is close to impossible to examine individual deformation mechanisms in macroscale tests, where local multiaxial stress states in polycrystalline structures will always favour multiple mechanisms of plasticity, we demonstrate that miniaturised uniaxial experiments conducted in-situ in the scanning electron microscope are ideally suited for a detailed assessment of specific processes.

A Novel Example of Metal-Mediated Aromatic Thiolation in a Ruthenium Complex. Crystal Structure of RuII(SC6H4NNC6H4N)2†

1996 ◽  
Vol 35 (10) ◽  
pp. 3050-3052 ◽  
Author(s):  
Bidyut Kumar Santra ◽  
Ganesh A. Thakur ◽  
Prasanta Ghosh ◽  
Amitava Pramanik ◽  
Goutam Kumar Lahiri
Keyword(s):  
Crystal Structure ◽  
Ruthenium Complex ◽  
Complex Crystal Structure ◽  
Complex Crystal
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