The dependence of coercivity and corrosion resistance on grain size in Nd-Fe-B-type sintered permanent magnets

1991 ◽  
Vol 3 (31) ◽  
pp. 5893-5901 ◽  
Author(s):  
S Szymura ◽  
H Bala ◽  
Yu M Rabinovich ◽  
V V Sergeev ◽  
G Pawlowska ◽  
...  
Keyword(s):  
Grain Size ◽  
Corrosion Resistance ◽  
Permanent Magnets ◽  
Sintered Permanent Magnets

Nucleus Size Determination for Nd2Fe14B, Sm2Co17, SmCo5 and BaFe12O19 Magnets

2012 ◽  
Vol 727-728 ◽  
pp. 151-156 ◽  
Author(s):  
Marcos Flavio de Campos ◽  
José Adilson de Castro
Keyword(s):  
Grain Size ◽  
Legendre Polynomials ◽  
Permanent Magnets ◽  
Critical Size ◽  
Size Determination ◽  
Nucleus Size ◽  
Spherical Cap ◽  
Global Energy ◽  
Domain Configuration ◽  
Sintered Permanent Magnets

The nucleus size was determined for the following phases: Nd2Fe14B, Sm2Co17, SmCo5and BaFe12O19. These phases are the basis for the most relevant sintered permanent magnets. For the determination, it was assumed a spherical grain, and that the reversal of magnetization occurs in a tiny shell near the surface. The Magnetostatic energy for each domain configuration was found by means of Legendre polynomials. The nucleus is a spherical cap, near the equator. After reaching the nucleus critical size, the reversal of magnetization continues spontaneously, reducing the global energy of the system. It was found that, for each grain size, there is a different nucleus size.

MICROSTRUCTURE AND COERCIVITY IN (Nd, Dy)-(Fe, Co)-B BASED SINTERED PERMANENT MAGNETS WITH MINOR Nb AND Ga ADDITIONS

1988 ◽  
Vol 49 (C8) ◽  
pp. C8-573-C8-574
Author(s):  
G. F. Zhou ◽  
X. K. Sun ◽  
Y. C. Chuang ◽  
L. Gao ◽  
Z. Yu ◽  
...  
Keyword(s):  
Permanent Magnets ◽  
Sintered Permanent Magnets

DOWMETAL ZK60A

Alloy Digest ◽  
1952 ◽  
Vol 1 (1) ◽  
Keyword(s):  
Fracture Toughness ◽  
Grain Size ◽  
Corrosion Resistance ◽  
High Resistance ◽  
High Strength ◽  
Heat Treating ◽  
Bend Strength ◽  
Chemical Company ◽  
Resistance To Stress ◽  
Extrusion Alloy

Abstract Dowmetal ZK60A is an ageable extrusion alloy for use where high strength magnesium extrusions with good toughness are required. It has small grain size, low notch sensitivity and a relatively high resistance to stress corrosion. This datasheet provides information on composition, physical properties, tensile properties, and compressive, shear, bearing, and bend strength as well as fracture toughness. It also includes information on corrosion resistance as well as forming, heat treating, machining, joining, and surface treatment. Filing Code: Mg-1. Producer or source: The Dow Chemical Company.

scholarly journals Influence of bimodal grain size distribution on the corrosion resistance of Mg-4Li-3Al-1Zn (LAZ431)

2021 ◽  
Author(s):  
Anna Dobkowska ◽  
Boguslawa Adamczyk – Cieślak ◽  
Dariusz Kuc ◽  
Eugeniusz Hadasik ◽  
Tomasz Płociński ◽  
...  
Keyword(s):  
Grain Size ◽  
Corrosion Resistance ◽  
Size Distribution ◽  
Grain Size Distribution ◽  
Bimodal Grain Size ◽  
Bimodal Grain Size Distribution

scholarly journals Development of Al–Mg–Si alloy performance by addition of grain refiner Al–5Ti–1B alloy

2021 ◽  
Vol 104 (2) ◽  
pp. 003685042110294
Author(s):  
Khaled Abd El-Aziz ◽  
Emad M Ahmed ◽  
Abdulaziz H Alghtani ◽  
Bassem F Felemban ◽  
Hafiz T Ali ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Corrosion Resistance ◽  
Testing Machine ◽  
Dendritic Structure ◽  
Grain Refiner ◽  
Corrosion Properties ◽  
Average Grain Size ◽  
Structural Applications ◽  
Alloy Addition

Aluminum alloys are the most essential part of all shaped castings manufactured, mainly in the automotive, food industry, and structural applications. There is little consensus as to the precise relationship between grain size after grain refinement and corrosion resistance; conflicting conclusions have been published showing that reduced grain size can decrease or increase corrosion resistance. The effect of Al–5Ti–1B grain refiner (GR alloy) with different percentages on the mechanical properties and corrosion behavior of Aluminum-magnesium-silicon alloy (Al–Mg–Si) was studied. The average grain size is determined according to the E112ASTM standard. The compressive test specimens were made as per ASTM: E8/E8M-16 standard to get their compressive properties. The bulk hardness using Vickers hardness testing machine at a load of 50 g. Electrochemical corrosion tests were carried out in 3.5 % NaCl solution using Autolab Potentiostat/Galvanostat (PGSTAT 30).The grain size of the Al–Mg–Si alloy was reduced from 82 to 46 µm by the addition of GR alloy. The morphology of α-Al dendrites changes from coarse dendritic structure to fine equiaxed grains due to the addition of GR alloy and segregation of Ti, which controls the growth of primary α-Al. In addition, the mechanical properties of the Al–Mg–Si alloy were improved by GR alloy addition. GR alloy addition to Al–Mg–Si alloy produced fine-grained structure and better hardness and compressive strength. The addition of GR alloy did not reveal any marked improvements in the corrosion properties of Al–Mg–Si alloy.

scholarly journals Study on the erosion of Mo/ZrO2 alloys in glass melting process

2020 ◽  
Vol 39 (1) ◽  
pp. 595-598
Author(s):  
Cui Chaopeng ◽  
Zhu Xiangwei ◽  
Li Qiang ◽  
Zhang Min ◽  
Zhu Guangping
Keyword(s):  
Grain Size ◽  
Corrosion Resistance ◽  
Powder Metallurgy ◽  
Hydrothermal Synthesis ◽  
Grain Boundaries ◽  
Electrode Material ◽  
Glass Melting ◽  
Melting Process ◽  
Fine Grain ◽  
Conventional Electrode

AbstractThe Mo/ZrO2 electrode was prepared by combining hydrothermal synthesis with powder metallurgy, and this new electrode material has a totally different microstructure from the conventional electrode. The grain size of the new electrode was fine, and the size of ZrO2 in the alloy reached 200 nm. According to the results, the Mo–ZrO2 electrode has better performance, because the erosion occurs along the grain boundaries. Meanwhile, the new electrode, based on its fine grain, can effectively improve the corrosion resistance of the electrode.

Structure of Low Cobalt Alloy for Permanent Magnets of Basis System Fe-Cr-Co at Complex Two-Level Loading in Isothermal Conditions

2007 ◽  
Vol 539-543 ◽  
pp. 2928-2933 ◽  
Author(s):  
V.S. Yusupov ◽  
A.I. Milyaev ◽  
Galia F. Korznikova ◽  
Alexander V. Korznikov ◽  
J.K. Kovneristii
Keyword(s):  
Grain Size ◽  
Active Zone ◽  
Single Phase ◽  
Permanent Magnets ◽  
Phase Region ◽  
The Body ◽  
Coarse Grained ◽  
Isothermal Conditions ◽  
Basis System ◽  
Level Loading

Results of experimental research into evolution of the structure and microhardness of the hard magnetic Fe-30Cr-8Co-0,7Ti-0,5V-0,7Si alloy during complex two-level loading (compression + torsion) in isothermal conditions at various temperatures in single-phase region are reported. It was revealed that the deformation leads to a strong refinement of initial coarse-grained structure in the whole volume of the sample, however the generated structure is non-uniform through the body of the sample. In an active zone of deformation, near to mobile head, there is a microcrystalline layer with a grain size of about 5 microns which thickness poorly depends on the formation. With removal from the active zone of deformation the grain size increases, and microhardness decreases.

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