scholarly journals In Situ Synchrotron Diffraction Analysis of Zn Additions on the Compression Properties of NK30

Materials ◽  
2019 ◽  
Vol 12 (23) ◽  
pp. 3935
Author(s):  
Domonkos Tolnai ◽  
Marie-Anne Dupont ◽  
Serge Gavras ◽  
Klaudia Fekete-Horváth ◽  
Andreas Stark ◽  
...  
Keyword(s):  
Room Temperature ◽  
Deformation Twin ◽  
Deformation Mechanisms ◽  
Synchrotron Diffraction ◽  
Compression Properties ◽  
Zn Addition ◽  
Synchrotron Radiation Diffraction ◽  
Twin Growth ◽  
Zn Alloys

In situ synchrotron radiation diffraction was performed during the compression of as-cast Mg–3Nd–Zn alloys with different amounts (0, 0.5, 1, and 2 wt %) of Zn addition at room temperature. During the tests, the acoustic emission signals of the samples were recorded. The results show that the addition of Zn decreased the strength of the alloys but, at the same time, increased their ductility. In the earlier stages of deformation, twin formation and basal slip were the dominant deformation mechanisms. The twins tended to grow during the entire compression stage; however, the formation of new twins dominated only at the beginning of the plastic deformation. In order to accommodate the strain levels, the alloys containing Zn underwent nonbasal slip in the later stages of deformation. This can be attributed to the presence of precipitates containing Zn in the microstructure, inhibiting twin growth.

scholarly journals Phase Formation during Solidification of Mg-Nd-Zn Alloys: An In Situ Synchrotron Radiation Diffraction Study

Materials ◽  
2018 ◽  
Vol 11 (9) ◽  
pp. 1637 ◽  
Author(s):  
Domonkos Tolnai ◽  
Tungky Subroto ◽  
Serge Gavras ◽  
Ricardo Buzolin ◽  
Andreas Stark ◽  
...  
Keyword(s):  
Rare Earth ◽  
Synchrotron Radiation ◽  
Diffraction Study ◽  
Phase Formation ◽  
Theoretical Calculations ◽  
Alloy System ◽  
Zn Addition ◽  
Synchrotron Radiation Diffraction ◽  
Zn Alloys

Mg-4Nd base alloys with Zn additions of 3, 5 and 8 wt % were investigated with in situ synchrotron radiation diffraction during solidification. This method enabled the investigation of phase formation and transformation in the alloys. The diffraction results were supported with TEM observations on the as-solidified samples. The results show the effect of increased Zn addition on stabilizing the Mg3RE phase (RE—rare earth). The experimental results agree only partially with the theoretical calculations indicating the need to improve the existing thermodynamic database on the alloy system.

Room Temperature Deformation Mechanisms of Alumina Particles Observed from In Situ Micro-compression and Atomistic Simulations

2015 ◽  
Vol 25 (1-2) ◽  
pp. 82-93 ◽  
Author(s):  
Pylin Sarobol ◽  
Michael Chandross ◽  
Jay D. Carroll ◽  
William M. Mook ◽  
Daniel C. Bufford ◽  
...  
Keyword(s):  
Room Temperature ◽  
Deformation Mechanisms ◽  
Atomistic Simulations ◽  
Temperature Deformation ◽  
Alumina Particles

Combined In Situ Neutron Diffraction and Acoustic Emission of Twin Nucleation & Twin Growth in Extruded ZM20 Mg Alloy

2010 ◽  
Vol 652 ◽  
pp. 149-154 ◽  
Author(s):  
Ondrej Muránsky ◽  
Matthew R. Barnett ◽  
David G. Carr ◽  
Sven C. Vogel ◽  
E.C. Oliver
Keyword(s):  
Acoustic Emission ◽  
Neutron Diffraction ◽  
Room Temperature ◽  
Coarse Grained ◽  
Fine Grained ◽  
Grain Sizes ◽  
Twin Nucleation ◽  
Twin Growth ◽  
In Situ Neutron Diffraction

In the present work in situ neutron diffraction and acoustic emission were used concurrently to study deformation twinning in two ZM20 Mg alloys with significantly different grain sizes at room temperature. The combination of these techniques allows differentionation between the twin nucleation and the twin growth mechanisms. It is shown, that yielding and immediate post-yielding plasticity in compression is governed primarily by twin nucleation, whereas the plasticity at higher strains is governed by twin growth. The current results further suggest that yielding by twinning happens in a slightly different manner in the fine-grained as compared to the coarse-grained alloy.

scholarly journals Wardite (NaAl3(PO4)2(OH)4·2H2O) at High Pressure: Compressional Behavior and Structure Evolution

Minerals ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 877
Author(s):  
G. Diego Gatta ◽  
Davide Comboni ◽  
Paolo Lotti ◽  
Alessandro Guastoni ◽  
Nicola Rotiroti ◽  
...  
Keyword(s):  
High Pressure ◽  
Pressure Range ◽  
Diamond Anvil Cell ◽  
Atomic Scale ◽  
Deformation Mechanisms ◽  
Structure Evolution ◽  
Synchrotron Diffraction ◽  
Diamond Anvil ◽  
Murnaghan Equation

The high-pressure behavior of wardite, NaAl3(PO4)2(OH)4·2H2O (a = 7.0673(2) Å, c = 19.193(9) Å, Sp. Gr. P41212), has been investigated by in-situ single-crystal synchrotron diffraction experiments up to 9 GPa, using a diamond anvil cell under quasi-hydrostatic conditions. This phosphate does not experience any pressure-induced phase transition, or anomalous compressional behavior, within the pressure-range investigated: its compressional behavior is fully elastic and all the deformation mechanisms, at the atomic scale, are reversible upon decompression. A second-order Birch–Murnaghan Equation of State was fitted to the experimental data, weighted by their uncertainty in pressure (P) and volume (V), with the following refined parameters: V0 = 957.8(2) Å3 and KV0 = −V0(∂P/∂V)P0,T0 = 85.8(4) GPa (βV0 = 1/KV0 = 0.01166(5) GPa−1). Axial bulk moduli were also calculated, with: K0(a) = 98(3) GPa (β0(a) = 0.0034(1) GPa−1) and K0(c) = 64(1) GPa (β0(c) = 0.0052(1) GPa−1). The anisotropic compressional scheme is: K0(a):K0(c) = 1.53:1. A series of structure refinements were performed on the basis of the intensity data collected in compression and decompression. The mechanisms at the atomic scale, responsible for the structure anisotropy of wardite, are discussed.

scholarly journals Influence of Volume Fraction of Long-Period Stacking Ordered Structure Phase on the Deformation Processes during Cyclic Deformation of Mg-Y-Zn Alloys

Crystals ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 11
Author(s):  
Daria Drozdenko ◽  
Gergely Farkas ◽  
Pavol Šimko ◽  
Klaudia Fekete ◽  
Jan Čapek ◽  
...  
Keyword(s):  
Path Dependence ◽  
Volume Fraction ◽  
Deformation Mechanisms ◽  
Electron Backscattered Diffraction ◽  
Long Period ◽  
Lpso Structure ◽  
Deformation Processes ◽  
In Situ Neutron Diffraction ◽  
Zn Alloys

Deformation mechanisms in extruded Mg-Y-Zn alloys with different volume fractions of the long-period stacking ordered (LPSO) structure have been investigated during cyclic loading, i.e., compression followed by unloading and reverse tensile loading. Electron backscattered diffraction (EBSD) and in situ neutron diffraction (ND) techniques are used to determine strain path dependence of the deformation mechanisms. The twinning-detwinning mechanism operated in the α-Mg phase is of key importance for the subsequent hardening behavior of alloys with complex microstructures, consisting of α-Mg and LPSO phases. Besides the detailed analysis of the lattice strain development as a function of the applied stress, the dislocation density evolution in particular alloys is determined.

scholarly journals Deformation Mechanisms in Metastable Austenitic TRIP/TWIP Steels under Compressive Load Studied by in situ Synchrotron Radiation Diffraction

2018 ◽  
Vol 21 (5) ◽  
pp. 1801101 ◽  
Author(s):  
Christiane Ullrich ◽  
Stefan Martin ◽  
Christian Schimpf ◽  
Andreas Stark ◽  
Norbert Schell ◽  
...  
Keyword(s):  
Synchrotron Radiation ◽  
Compressive Load ◽  
Deformation Mechanisms ◽  
Synchrotron Radiation Diffraction ◽  
Twip Steels

Deformation Mechanisms of Aluminum at High Temperatures: in situ Straining Experiments in H.V.E.M.

1975 ◽  
Vol 33 ◽  
pp. 56-57
Author(s):  
D. Caillard ◽  
P. Muchin ◽  
J. L. Martin
Keyword(s):  
High Temperature ◽  
Dislocation Density ◽  
Single Crystals ◽  
High Temperatures ◽  
Room Temperature ◽  
Dislocation Climb ◽  
Deformation Mechanisms ◽  
High Angle ◽  
The One

Aluminium single crystals have been deformed on a straining holder between room temperature and 550° C in a H.V.E.M. Observations are recorded on still photographs or movies.Evidence is shown of crosslip and dislocation climb.1) The formation of dislocation subboundaries has been observed at high temperature and low stresses. The increase with time of dislocation density of each boundary is explained and the coalescence of low angle subboundaries into high angle ones, is described on the basis of our observations by a model involving dislocation climb, different from the one proposed formerly by Dunn and Hibbard.

scholarly journals Microstructural Changes Influencing the Magnetoresistive Behavior of Bulk Nanocrystalline Materials

2020 ◽  
Vol 10 (15) ◽  
pp. 5094
Author(s):  
Stefan Wurster ◽  
Martin Stückler ◽  
Lukas Weissitsch ◽  
Timo Müller ◽  
Andrea Bachmaier
Keyword(s):  
Nanocrystalline Materials ◽  
Giant Magnetoresistance ◽  
Room Temperature ◽  
Annealing Temperature ◽  
High Pressure Torsion ◽  
Ex Situ ◽  
Thermal Treatments ◽  
Synchrotron Diffraction ◽  
Bulk Nanocrystalline

Bulk nanocrystalline materials of small and medium ferromagnetic content were produced using severe plastic deformation by high-pressure torsion at room temperature. Giant magnetoresistive behavior was found for as-deformed materials, which was further improved by adjusting the microstructure with thermal treatments. The adequate range of annealing temperatures was assessed with in-situ synchrotron diffraction measurements. Thermally treated Cu–Co materials show larger giant magnetoresistance after annealing for 1 h at 300 °C, while for Cu-Fe this annealing temperature is too high and decreases the magnetoresistive properties. The improvement of magnetoresistivity by thermal treatments is discussed with respect to the microstructural evolution as observed by electron microscopy and ex-situ synchrotron diffraction measurements.

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