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B Davis - One of the best experts on this subject based on the ideXlab platform.
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particle effects on recrystallization in magnesium Manganese Alloys particle pinning
Materials Science and Engineering A-structural Materials Properties Microstructure and Processing, 2011Co-Authors: J D Robson, Dominic Henry, B DavisAbstract:Abstract Dispersoid particles are widely used in wrought aluminium Alloys to control grain structure during thermomechanical processing. The aim of this work was to investigate whether this approach could be utilized in wrought magnesium Alloys to obtain better control of recrystallization. A binary magnesium–Manganese alloy was heat treated to produce a fine dispersion of Manganese precipitates. The effect of this dispersion on dynamic and static recrystallization during channel die deformation (at a slow strain rate), hot rolling, and annealing was studied and compared with that of an alloy free of fine particles. It was found that the presence of particles did not suppress dynamic recrystallization during channel die deformation. Fine particles did lead to a much reduced recrystallized fraction after hot rolling, attributed to a retardation of static recrystallization kinetics. Although the presence of pinning particles greatly slowed recrystallization kinetics on annealing, for no conditions studied was it possible to prevent recrystallization of the as-deformed structure using particles.
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particle effects on recrystallization in magnesium Manganese Alloys particle stimulated nucleation
Acta Materialia, 2009Co-Authors: J D Robson, Dominic Henry, B DavisAbstract:The influence of large (>1μm diameter) particles on the recrystallization behaviour of magnesium Alloys deformed in plane strain compression has been studied. Deformation zones characterized by a misorientation gradient were observed surrounding large particles, which were similar to those seen in other Alloys where particle-stimulated nucleation (PSN) of recrystallization occurs. During annealing, new grains formed by PSN, but only at a small fraction of the coarse particles. Recrystallization was instead dominated by growth of existing dynamically recrystallized grains and nucleation of new grains from the deformed grain mantle region.
J D Robson - One of the best experts on this subject based on the ideXlab platform.
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particle effects on recrystallization in magnesium Manganese Alloys particle pinning
Materials Science and Engineering A-structural Materials Properties Microstructure and Processing, 2011Co-Authors: J D Robson, Dominic Henry, B DavisAbstract:Abstract Dispersoid particles are widely used in wrought aluminium Alloys to control grain structure during thermomechanical processing. The aim of this work was to investigate whether this approach could be utilized in wrought magnesium Alloys to obtain better control of recrystallization. A binary magnesium–Manganese alloy was heat treated to produce a fine dispersion of Manganese precipitates. The effect of this dispersion on dynamic and static recrystallization during channel die deformation (at a slow strain rate), hot rolling, and annealing was studied and compared with that of an alloy free of fine particles. It was found that the presence of particles did not suppress dynamic recrystallization during channel die deformation. Fine particles did lead to a much reduced recrystallized fraction after hot rolling, attributed to a retardation of static recrystallization kinetics. Although the presence of pinning particles greatly slowed recrystallization kinetics on annealing, for no conditions studied was it possible to prevent recrystallization of the as-deformed structure using particles.
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particle effects on recrystallization in magnesium Manganese Alloys particle stimulated nucleation
Acta Materialia, 2009Co-Authors: J D Robson, Dominic Henry, B DavisAbstract:The influence of large (>1μm diameter) particles on the recrystallization behaviour of magnesium Alloys deformed in plane strain compression has been studied. Deformation zones characterized by a misorientation gradient were observed surrounding large particles, which were similar to those seen in other Alloys where particle-stimulated nucleation (PSN) of recrystallization occurs. During annealing, new grains formed by PSN, but only at a small fraction of the coarse particles. Recrystallization was instead dominated by growth of existing dynamically recrystallized grains and nucleation of new grains from the deformed grain mantle region.
Shigemi Mizukami - One of the best experts on this subject based on the ideXlab platform.
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detecting quadrupole a hidden source of magnetic anisotropy for Manganese Alloys
Scientific Reports, 2020Co-Authors: Jun Okabayashi, Akimasa Sakuma, Yoshio Miura, Yohei Kota, K Suzuki, Shigemi MizukamiAbstract:Mn-based Alloys exhibit unique properties in the spintronics materials possessing perpendicular magnetic anisotropy (PMA) beyond the Fe and Co-based Alloys. It is desired to figure out the quantum physics of PMA inherent to Mn-based Alloys, which have never been reported. Here, the origin of PMA in ferrimagnetic Mn3− δ Ga ordered Alloys is investigated to resolve antiparallel-coupled Mn sites using x-ray magnetic circular and linear dichroism (XMCD/XMLD) and a first-principles calculation. We found that the contribution of orbital magnetic moments in PMA is small from XMCD and that the finite quadrupole-like orbital distortion through spin-flipped electron hopping is dominant from XMLD and theoretical calculations. These findings suggest that the spin-flipped orbital quadrupole formations originate from the PMA in Mn3− δ Ga and bring the paradigm shift in the researches of PMA materials using x-ray magnetic spectroscopies.
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detecting quadrupole a hidden source of magnetic anisotropy for Manganese Alloys
arXiv: Materials Science, 2020Co-Authors: Jun Okabayashi, Akimasa Sakuma, Yoshio Miura, Yohei Kota, K Suzuki, Shigemi MizukamiAbstract:Mn-based Alloys exhibit unique properties in the spintronics materials possessing perpendicular magnetic anisotropy (PMA) beyond the Fe and Co-based Alloys. It is desired to figure out the quantum physics of PMA inherent to Mn-based Alloys, which have never been reported. Here, the origin of PMA in ferrimagnetic Mn$_{3-{\delta}}$Ga ordered Alloys is investigated to resolve antiparallel-coupled Mn sites using x-ray magnetic circular and linear dichroism (XMCD/XMLD) and a first-principles calculation. We found that the contribution of orbital magnetic moments in PMA is small from XMCD and that the finite quadrupole-like orbital distortion through spin-flipped electron hopping is dominant from XMLD and theoretical calculations. These findings suggest that the spin-flipped orbital quadrupole formations originate from the PMA in Mn$_{3-{\delta}}$Ga and bring the paradigm shift in the researches of PMA materials using x-ray magnetic spectroscopies.
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long lived ultrafast spin precession in Manganese Alloys films with a large perpendicular magnetic anisotropy
Physical Review Letters, 2011Co-Authors: Shigemi Mizukami, D Watanabe, Hiroshi Naganuma, Mikihiko Oogane, F Wu, Akimasa Sakuma, Jakob Walowski, Takahide Kubota, Xuefeng Zhang, Yasuo AndoAbstract:: Spin precession with frequencies up to 280 GHz is observed in Mn(3-δ)Ga alloy films with a perpendicular magnetic anisotropy constant K(u)∼15 M erg/cm(3). The damping constant α, characterizing macroscopic spin relaxation and being a key factor in spin-transfer-torque systems, is not larger than 0.008 (0.015) for the δ=1.46 (0.88) film. Those are about one-tenth of α values for known materials with large K(u). First-principles calculations well describe both low α and large K(u) for these Alloys.
Jan Bohlen - One of the best experts on this subject based on the ideXlab platform.
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effect of aluminium and calcium on the microstructure texture plastic deformation and related acoustic emission of extruded magnesium Manganese Alloys
Journal of Alloys and Compounds, 2014Co-Authors: Kseniya Illkova, Karl Ulrich Kainer, Dietmar Letzig, Patrik Dobroň, Frantisek Chmelik, J Balik, Jan BohlenAbstract:Abstract Alloying modifications with Ca and Al of a binary Mg-1 wt.% Mn have been used to investigate the microstructure development during extrusion and the relation between these microstructures and the mechanical properties. Acoustic emission (AE) measurements were used to analyse dislocation or twin dominated deformation in differently textured fractions of the microstructure during tensile and compression testing. Ca appears to have a texture modifying effect and leads to the formation of unusual texture components with a tilt of basal planes out of the extrusion direction. This texture development has previously been described for rare earth containing magnesium Alloys after extrusion. Al as an alloying element does not lead to the formation of such a component. Both elements have in common, that the alignment of basal plane normals perpendicular to the extrusion direction is reduced, having a substantial effect on the mechanical properties. Partially recrystallised microstructures obtained in Mg-1 wt.% Mn-0.3 wt.% Ca and Mg-1 wt.% Mn-1 wt.% Al after slow extrusion exhibit bimodal grain size distributions. Only in the case of Mg-1 wt.% Mn-8 wt.% Al a fully recrystallised microstructure is found, indicating differences in the grain nucleation rate during recrystallisation. In this alloy, the weakest texture and, correspondingly, the lowest asymmetry in mechanical properties was also observed.
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effect of rare earth elements on the microstructure and texture development in magnesium Manganese Alloys during extrusion
Materials Science and Engineering A-structural Materials Properties Microstructure and Processing, 2010Co-Authors: Jan Bohlen, Sangbong Yi, Dietmar Letzig, Karl Ulrich KainerAbstract:Abstract Single additions of the rare earth (RE) elements cerium, yttrium or neodymium have been made to magnesium–Manganese Alloys in order to investigate their influence on the microstructure and texture formed during indirect extrusion and the resulting mechanical properties. Whereas the binary Mg–Mn alloy M1 exhibits a 〈10.0〉 or 〈10.0〉–〈11.0〉 fibre texture depending on the extrusion rate, the RE-containing Alloys exhibit weaker recrystallisation textures and the formation of a new texture component. The preferential growth of grains having 〈11.0〉 parallel to the extrusion direction was hindered in these Alloys. For the rare earth elements used in this work it appears that Nd is a much stronger texture modifier compared to Ce or Y in Mg–Mn Alloys. The weaker texture leads to increased ductility, lower yield and ultimate stresses, but a decrease in the asymmetric yield behaviour of the extruded bars.
Dominic Henry - One of the best experts on this subject based on the ideXlab platform.
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particle effects on recrystallization in magnesium Manganese Alloys particle pinning
Materials Science and Engineering A-structural Materials Properties Microstructure and Processing, 2011Co-Authors: J D Robson, Dominic Henry, B DavisAbstract:Abstract Dispersoid particles are widely used in wrought aluminium Alloys to control grain structure during thermomechanical processing. The aim of this work was to investigate whether this approach could be utilized in wrought magnesium Alloys to obtain better control of recrystallization. A binary magnesium–Manganese alloy was heat treated to produce a fine dispersion of Manganese precipitates. The effect of this dispersion on dynamic and static recrystallization during channel die deformation (at a slow strain rate), hot rolling, and annealing was studied and compared with that of an alloy free of fine particles. It was found that the presence of particles did not suppress dynamic recrystallization during channel die deformation. Fine particles did lead to a much reduced recrystallized fraction after hot rolling, attributed to a retardation of static recrystallization kinetics. Although the presence of pinning particles greatly slowed recrystallization kinetics on annealing, for no conditions studied was it possible to prevent recrystallization of the as-deformed structure using particles.
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particle effects on recrystallization in magnesium Manganese Alloys particle stimulated nucleation
Acta Materialia, 2009Co-Authors: J D Robson, Dominic Henry, B DavisAbstract:The influence of large (>1μm diameter) particles on the recrystallization behaviour of magnesium Alloys deformed in plane strain compression has been studied. Deformation zones characterized by a misorientation gradient were observed surrounding large particles, which were similar to those seen in other Alloys where particle-stimulated nucleation (PSN) of recrystallization occurs. During annealing, new grains formed by PSN, but only at a small fraction of the coarse particles. Recrystallization was instead dominated by growth of existing dynamically recrystallized grains and nucleation of new grains from the deformed grain mantle region.