Magnetic properties and microstructures of the (SmFe10V2) 1 − x-(Sm2Fe17)x cast alloys

1995 ◽  
Vol 42 (4) ◽  
pp. 298-301 ◽  
Author(s):  
Satoshi Sugimoto ◽  
Tomoyasu Shimono ◽  
Hajime Nakamura ◽  
Toshio Kagotani ◽  
Masuo Okada ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Cast Alloys

scholarly journals Magnetic Properties of Anisotropic Nd-Fe-B HDDR Powders Prepared from Strip Cast Alloys.

2002 ◽  
Vol 49 (12) ◽  
pp. 1094-1097
Author(s):  
Koichiro Morimoto ◽  
Kenichi Kato ◽  
Kazunori Igarashi ◽  
Ryoji Nakayama
Keyword(s):  
Magnetic Properties ◽  
Cast Alloys ◽  
Strip Cast

Microstructural and Magnetic Improvements in Tube-Cast Pr-Fe-B-Cu Alloys Via Heat Treatments and Rapid Upset Forging

1999 ◽  
Vol 577 ◽  
Author(s):  
G P Hatch ◽  
A J Williams ◽  
I R Harris
Keyword(s):  
Magnetic Properties ◽  
Heat Treatments ◽  
Cast State ◽  
Steel Tubes ◽  
Cu Alloys ◽  
Upset Forging ◽  
Cast Alloys ◽  
Optimum Heat ◽  
Alternative Routes ◽  
Optimum Heat Treatment

ABSTRACTAlloys of Pr-Fe-B-Cu were cast into Cu and stainless steel tubes. It could be seen that a preferred crystallographic orientation was obtained after cooling. Fine platelets of Pr2Fe1 4B matrix phase were formed, surrounded by various grain boundary phases, and there was a significant reduction in the amount of free Fe present, in comparison to conventional slab cast alloys. In order to improve the magnetic properties in the as-cast state, two alternative routes were used. The first involved a series of two step heat treatments to develop an improved microstructure. After an optimum heat treatment of 1000 'C for 24 hours + 500°C for 3 hours, significantly improved magnetic properties were obtained for a 17.5 % Pr alloy; Br = 752 mT, Hci = 613 kAm−1 and BHmax = 96 kJm−3. The second route involved a rapid upset forging [RUF] process, with a strain rate of 11.5 s−1, to hot deform the alloys. Following post-forging heat treatments, properties of Br = 966 mT, Hci = 780 kAm−3 and BHmax = 160 kJm−3 were obtained for a 15% Pr alloy. That nature of the improvements in properties as a result of heat treatments and RUF were investigated and are discussed in the present work.

Texture Development in Nd-Fe-V and Nd-Fe-B Alloys by Hot Forging in View of Improving Permanent Magnet Properties

2005 ◽  
Vol 105 ◽  
pp. 291-296
Author(s):  
Sophie Rivoirard ◽  
I. Popa ◽  
Daniel Chateigner ◽  
B. Ouladdiaf ◽  
Patricia de Rango ◽  
...  
Keyword(s):  
Grain Size ◽  
Magnetic Properties ◽  
Neutron Diffraction ◽  
High Speed ◽  
Magnetic Phase ◽  
Hot Forging ◽  
Forging Process ◽  
Cast Alloys ◽  
Hot Forging Process ◽  
Anisotropic Magnet

A high speed hot forging process was applied to Nd-Fe-B and Nd-Fe-V as cast alloys in order to develop both the microstructure and the crystallographic texture appropriate for permanent anisotropic magnet properties. Neutron diffraction texture analyses are used to demonstrate the effect of the hot forging process on both kind of alloys. Microstructural changes are an important feature on forging in both cases. Coercivity is developed in the Nd-Fe-B alloy mainly from grain size reduction and disappearance of free iron. Stabilisation of the Nd(Fe,V)12 hard magnetic phase is achieved from the iron and Nd-rich microstructure of the starting Nd-Fe-V material. A comparison of the crystallographic textures of Nd2Fe14B and Nd(Fe,V)12 phases is done to account for the development of extrinsic magnetic anisotropy. In both cases, a nearly fibre texture is obtained in correlation with the symmetry of the deformation. However, the orientations are quite different in both alloys and the consequences on the magnetic properties are evidenced.

Magnetic properties of Sm2+αFe17N powders prepared from bulk and strip-cast alloys

2021 ◽  
Vol 518 ◽  
pp. 167416
Author(s):  
D.A. Kolodkin ◽  
A.G. Popov ◽  
A.V. Protasov ◽  
V.S. Gaviko ◽  
D.Yu. Vasilenko ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Cast Alloys ◽  
Strip Cast

Magnetic properties of anisotropic Nd–Fe–B HDDR powders prepared from strip cast alloys

2004 ◽  
Vol 366 (1-2) ◽  
pp. 274-278 ◽  
Author(s):  
K. Morimoto ◽  
K. Kato ◽  
K. Igarashi ◽  
R. Nakayama
Keyword(s):  
Magnetic Properties ◽  
Cast Alloys ◽  
Strip Cast

Influence of Alloying Elements Zr, Nb and Mo on the Microstructure and Magnetic Properties of Sintered Pr-Fe-Co-B Based Permanent Magnets

2018 ◽  
Vol 930 ◽  
pp. 440-444
Author(s):  
Melissa Rohrig Martins da Silva ◽  
R.G.T. Fim ◽  
S.C. Silva ◽  
Julio Cesar Serafim Casini ◽  
P.A.P. Wendhausen ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Permanent Magnets ◽  
Maximum Energy ◽  
Alloying Elements ◽  
Maximum Energy Product ◽  
Energy Product ◽  
Cast Alloys ◽  
Hydrogen Decrepitation ◽  
Microstructure And Magnetic Properties

The addition of alloying elements on rare-earth permanent magnets is one of the methods used to improve the magnetic properties. This present work evaluates the influence of alloying elements such as Zr, Nb and Mo on the microstructure and magnetic properties of sintered Pr-FeCo-B based permanent magnets. The permanent magnets were produced by the conventional powder metallurgy route using powder obtained by hydrogen-decrepitation (HD) method from as cast alloys. In order to produce the magnet Pr16Fe66,9Co10,7B5,7Cu0,7 without alloying elements the mixture of alloys method was employed, mixing two compositions: Pr20Fe73B5Cu2 (33% w.t) and Pr14Fe64Co16B6 (67% w.t). With the purpose of evaluating the influence of the alloying elements, the Pr14Fe64Co16B6X0,1 (where X= Zr, Nb or Mo) (67% w.t) alloy was employed. The characterization of the alloys and the magnets was carried out using scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDXS) and the magnetic properties were measured using a permeameter. The magnet without any additions presented the highest intrinsic coercivity (μ0iHc = 748 KA.m-1) while the magnet with Nb addition presented higher remanence (Br = 1,04 T). The magnet with Zr addition presented the highest maximum energy product (BHmáx = 144 KJ.m-3), and the magnet with Mo addition showed the highest squareness factor (SF = 0,73).

Processing Sm-Fe(Ta)-N hard magnetic materials

1999 ◽  
Vol 577 ◽  
Author(s):  
K Žužek ◽  
PJ Mcguiness ◽  
S Kobe
Keyword(s):  
Particle Size ◽  
Magnetic Properties ◽  
Permanent Magnets ◽  
Processing Parameters ◽  
High Energy ◽  
Small Particle Size ◽  
Optimum Conditions ◽  
Hard Magnetic Materials ◽  
Negative Effect ◽  
Cast Alloys

ABSTRACTSmFe based alloys interstitially modified with nitrogen are potential candidates for high energy permanent magnets. In order to obtain the optimum properties a thorough understanding of the starting material and processing parameters is required. The microstructures of two cast alloys of composition Sm13.8Fe82.2 Ta4.0 and Sm13.7 Fe86.3 were carefully examined with a SEM equipped with EDX and the exact stoichiometries of the phases were determined. The SmFeTa material was found to contain significant amounts of TaFe2as well as the Sm2Fe17, SmFe2, SmFe3 phases observed in the SmFe material but without the a-iron dendrites which are characteristic of the latter material. The optimum conditions necessary to provide the highest coercivities using the conventional HDDR process, and for the HDDR process combined with pre-milling were investigated. The coercivities obtained after using the HDDR process and subsequent nitriding were 680 kA/m for the SmFeTaN and 360 kA/m for the SmFeN samples. Significantly higher coercivites of 1000 kA/m for SmFeN and 1275 kA/m for SmFeTaN were achieved by reducing the particle size with milling prior to the HDDR process.The better coercivities obtained with the Ta containing sample were found to be due to the presence of a much smaller amount of a. The milling prior to the HDDR treatment improves the magnetic properties because of the small particle size which prevents the grains growing too large, with their consequent very negative effect on the coercivity.

AEM analysis of crystallization in Ti-based amorphous alloys

1983 ◽  
Vol 41 ◽  
pp. 270-271
Author(s):  
A.R. Pelton ◽  
A.F. Marshall ◽  
Y.S. Lee
Keyword(s):  
Magnetic Properties ◽  
Amorphous Alloys ◽  
Amorphous Materials ◽  
Isothermal Annealing ◽  
Amorphous Matrix ◽  
Nucleation And Growth ◽  
Current Interest ◽  
Amorphous Films ◽  
Electrical And Magnetic Properties

Amorphous materials are of current interest due to their desirable mechanical, electrical and magnetic properties. Furthermore, crystallizing amorphous alloys provides an avenue for discerning sequential and competitive phases thus allowing access to otherwise inaccessible crystalline structures. Previous studies have shown the benefits of using AEM to determine crystal structures and compositions of partially crystallized alloys. The present paper will discuss the AEM characterization of crystallized Cu-Ti and Ni-Ti amorphous films.Cu60Ti40: The amorphous alloy Cu60Ti40, when continuously heated, forms a simple intermediate, macrocrystalline phase which then transforms to the ordered, equilibrium Cu3Ti2 phase. However, contrary to what one would expect from kinetic considerations, isothermal annealing below the isochronal crystallization temperature results in direct nucleation and growth of Cu3Ti2 from the amorphous matrix.

Microstructure in soft magnetic E3 (S1, Al) (Sendust) alloys

1988 ◽  
Vol 46 ◽  
pp. 770-771
Author(s):  
June D. Kim
Keyword(s):  
Electron Microscopy ◽  
Magnetic Properties ◽  
Ternary Phase Diagram ◽  
Vertical Tube ◽  
Vacuum Induction Melting ◽  
Induction Melting ◽  
Soft Magnetic ◽  
Quenching Temperature ◽  
Thin Foils ◽  
Vertical Tube Furnace

Iron-base alloys containing 8-11 wt.% Si, 4-8 wt.% Al, known as “Sendust” alloys, show excellent soft magnetic properties. These magnetic properties are strongly dependent on heat treatment conditions, especially on the quenching temperature following annealing. But little has been known about the microstructure and the Fe-Si-Al ternary phase diagram has not been established. In the present investigation, transmission electron microscopy (TEM) has been used to study the microstructure in a Sendust alloy as a function of temperature.An Fe-9.34 wt.% Si-5.34 wt.% Al (approximately Fe3Si0.6Al0.4) alloy was prepared by vacuum induction melting, and homogenized at 1,200°C for 5 hrs. Specimens were heat-treated in a vertical tube furnace in air, and the temperature was controlled to an accuracy of ±2°C. Thin foils for TEM observation were prepared by jet polishing using a mixture of perchloric acid 15% and acetic acid 85% at 10V and ∼13°C. Electron microscopy was performed using a Philips EM 301 microscope.

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