Magnetic Properties and Microstructure of a FeCo Ferritic Steel after Severe Plastic Deformation

2006 ◽  
Vol 503-504 ◽  
pp. 299-304 ◽  
Author(s):  
A. Vorhauer ◽  
K. Rumpf ◽  
P. Granitzer ◽  
Siegfried Kleber ◽  
H. Krenn ◽  
...  
Keyword(s):  
Plastic Deformation ◽  
Magnetic Properties ◽  
Severe Plastic Deformation ◽  
Ferritic Steel ◽  
Coarse Grained ◽  
Soft Magnetic ◽  
Microstructural Refinement ◽  
Coarse Grained State ◽  
Deformed State ◽  
Magnetization Behavior

A commercial FeCo ferritic steel with an initial grain size of 10 μm was subjected to Severe Plastic Deformation in a temperature range between 293 K (0.16Tm, Tm: melting temperature in K) and 723 K (0.4Tm) up to strain levels where a saturation of the microstructural refinement is observed. The microstructure of the severely deformed state is analyzed by Back Scattered Electrons micrographs captured in a SEM. The magnetic properties were characterized by means of SQUID-magnetometer providing information about the magnetization behavior of the material in the as processed state. Depending on the deformation temperature mean microstructural sizes in the steady state of 50 nm and 270 nm were observed after SPD at 293 K and 723 K, respectively. These small microstructural sizes influences significantly the magnetic properties of the material: it shifts the behavior from soft-magnetic in the initial coarse grained state towards a hard-magnetic with decreasing size of the crystallites. For sizes of the crystallites smaller than about 100 nm the magnetic properties become again more soft-magnetic.

Tailoring the Magnetic Properties of Ferritic Alloys by HPT

2008 ◽  
Vol 584-586 ◽  
pp. 923-928 ◽  
Author(s):  
Stephan Scheriau ◽  
K. Rumpf ◽  
Siegfried Kleber ◽  
Reinhard Pippan
Keyword(s):  
Grain Size ◽  
Magnetic Properties ◽  
Liquid Nitrogen Temperature ◽  
Magnetic Behaviour ◽  
Coarse Grained ◽  
Soft Magnetic ◽  
Ferritic Alloys ◽  
Coarse Grained State ◽  
Crystallite Sizes ◽  
Deformed State

Industrial available FeSi, FeCo and FeNi alloys with an initial grain size of 20-50 m were subjected to Severe Plastic Deformation (SPD) up to strain levels where a saturation of the microstructural refinement is observed. For both SPD conditions, ambient temperature (293 K) and liquid nitrogen temperature (77 K), the microstructure of the severely deformed state is analysed by Back Scattered Electrons (BSE) micrographs captured in a SEM. Additionally, samples that were deformed at 77 K are examined in a Transmission Electron Microscope (TEM). The magnetic properties were characterised by means of SQUID-magnetography providing information about the magnetization behaviour of the material in the as-processed state. Depending on the SPD conditions the mean microstructural sizes in the steady state are about 100-150 nm and 30-80 nm at 293 K and 77 K, respectively. The small microstructural sizes influence significantly the magnetic properties of these ferritic alloys. The initial soft-magnetic behaviour of the coarse grained state shifts towards a hard-magnetic with decreasing crystallite size. For crystallite sizes smaller than ~80 nm the magnetic properties become again more soft-magnetic. The experiments show that very low coercitivity can be obtained by SPD if the grain size is smaller than ~50 nm.

scholarly journals Sampling the Cu–Fe–Co phase diagram by severe plastic deformation for enhanced soft magnetic properties

2021 ◽  
Vol 12 ◽  
pp. 1235-1242
Author(s):  
Martin Stückler ◽  
Lukas Weissitsch ◽  
Stefan Wurster ◽  
Heinz Krenn ◽  
Reinhard Pippan ◽  
...  
Keyword(s):  
Phase Diagram ◽  
Plastic Deformation ◽  
Magnetic Properties ◽  
Severe Plastic Deformation ◽  
Soft Magnetic Properties ◽  
Soft Magnetic

Structure and Hardness of Cryorolled and Heat-Treated 2xxx Aluminum Alloy

2010 ◽  
Vol 667-669 ◽  
pp. 925-930
Author(s):  
S.V. Krymskiy ◽  
Elena Avtokratova ◽  
M.V. Markushev ◽  
Maxim Yu. Murashkin ◽  
O.S. Sitdikov
Keyword(s):  
Heat Treatment ◽  
Solid Solution ◽  
Plastic Deformation ◽  
Aluminum Alloy ◽  
Severe Plastic Deformation ◽  
Coarse Grained ◽  
Aging Response ◽  
Heat Treated ◽  
Aluminum Solid Solution ◽  
A Cell

The effects of severe plastic deformation (SPD) by isothermal rolling at the temperature of liquid nitrogen combined with prior- and post-SPD heat treatment, on microstructure and hardness of Al-4.4%Cu-1.4%Mg-0.7%Mn (D16) alloy were investigated. It was found no nanostructuring even after straining to 75%. Сryodeformation leads to microshear banding and processing the high-density dislocation substructures with a cell size of ~ 100-200 nm. Such a structure remains almost stable under 1 hr annealing up to 200oC and with further temperature increase initially transforms to bimodal with a small fraction of nanograins and then to uniform coarse grained one. It is found the change in the alloy post–SPD aging response leading to more active decomposition of the preliminary supersaturated aluminum solid solution, and to the alloy extra hardening under aging with shorter times and at lower temperatures compared to T6 temper.

Modern Models of Grain Boundary Diffusion

2011 ◽  
Vol 312-315 ◽  
pp. 1116-1125
Author(s):  
Vladimir V. Popov
Keyword(s):  
Plastic Deformation ◽  
Grain Boundary ◽  
Severe Plastic Deformation ◽  
Nanocrystalline Materials ◽  
Boundary Diffusion ◽  
Grain Boundary Diffusion ◽  
Coarse Grained ◽  
Gas Condensation ◽  
Non Equilibrium

Recent models of grain-boundary diffusion are briefly reviewed. Models of diffusion along equilibrium boundaries of recrystallization origin in coarse-grained materials and along non-equilibrium boundaries in nanocrystalline materials obtained by gas condensation and compacting or by severe plastic deformation are considered separately.

scholarly journals Aging Behaviour of Al-Mg-Si Alloys Subjected to Severe Plastic Deformation by ECAP and Cold Asymmetric Rolling

2011 ◽  
Vol 2011 ◽  
pp. 1-8 ◽  
Author(s):  
S. Farè ◽  
N. Lecis ◽  
M. Vedani
Keyword(s):  
Plastic Deformation ◽  
Severe Plastic Deformation ◽  
Isothermal Aging ◽  
Room Temperature ◽  
Coarse Grained ◽  
Peak Shape ◽  
Asymmetric Rolling ◽  
Ultrafine Grained ◽  
Aging Kinetics ◽  
Reduced Intensity

A study was carried out on aging behaviour of a 6082 alloy processed by two different severe plastic deformation techniques: ECAP and asymmetric rolling. Both techniques were able to generate an ultrafine-grained structure in samples processed at room temperature. It was stated that severe straining promotes marked changes in the postdeformation aging kinetics. The peaks of β′′/β′ transition phases were anticipated and of progressively reduced intensity over the coarse grained alloy. A further peak accounting for onset of recrystallization also appeared in the most severely deformed samples. Full consistency in peak shape and position was found when comparing materials processed by ECAP and asymmetric rolling. Isothermal aging treatments performed at 180°C revealed that in the severely deformed samples, aging became so fast that the hardness curves continuously decreased due to overwhelming effects of structure restoration. On the contrary, aging at 130°C offers good opportunities for fully exploiting the precipitate hardening effects in the ultrafine-grained alloy.

The Effect of Structural State on Magnetic and Magnetocaloric Properties of Micro-and Nanocrystalline Gd

2012 ◽  
Vol 190 ◽  
pp. 315-318 ◽  
Author(s):  
S.A. Nikitin ◽  
A.I. Smarzhevskaya ◽  
T.P. Kaminskaya ◽  
A.S. Semisalova ◽  
V.V. Popov ◽  
...  
Keyword(s):  
Plastic Deformation ◽  
Magnetic Properties ◽  
Severe Plastic Deformation ◽  
Structural State ◽  
Magnetic Entropy ◽  
Marked Influence ◽  
Magnetocaloric Properties

The effect of micro-and nanocrystalline structural state on magnetic properties and magnetic entropy (ΔSM) of Gd is investigated. The marked influence of severe plastic deformation on ΔSM is demonstrated.

Micro-Nanostructure Formation Mechanism of High-Mg Al Alloy

2019 ◽  
Vol 11 (10) ◽  
pp. 1338-1348
Author(s):  
Zeyi Hu ◽  
Wenliang Liu ◽  
Caihe Fan
Keyword(s):  
Mechanical Properties ◽  
Plastic Deformation ◽  
Severe Plastic Deformation ◽  
Formation Mechanism ◽  
Microstructure Evolution ◽  
Coarse Grained ◽  
Al Alloy ◽  
Nanostructure Formation ◽  
Superior Mechanical Properties ◽  
Alloy Strength

Micro-nanostructured materials have superior mechanical properties compared with coarse-grained materials. Severe plastic deformation (SPD) can effectively refine grains, resulting in the formation of typical micro-nanostructures. Fine grains improve alloy strength and toughness. This review summarizes the application of several typical SPD methods for high-Mg Al alloy. The effects of different SPD methods on the microstructure evolution, micro-nanostructure formation mechanism, and mechanical properties of the high-Mg Al alloy are analyzed in sequence. Finally, the development and future of the high-Mg Al alloy micro/nanostructure regulation are described.

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