Ferromagnetic bulk amorphous alloys

1998 ◽  
Vol 29 (7) ◽  
pp. 1779-1793 ◽  
Author(s):  
Akihisa Inoue ◽  
Akira Takeuchi ◽  
Tao Zhang
2011 ◽  
Vol 10 (04n05) ◽  
pp. 1013-1017
Author(s):  
T. KARAN ◽  
S. RAM ◽  
M. STOICA ◽  
J. ECKERT

Iron and cobalt based ferromagnetic bulk amorphous alloys have received considerable interest nowadays in view of their useful properties for wide spread applications in magnet technology, shape memory alloys, high frequency communications at low power loss, and other devices. In this purview, here we report synthesis and thermal properties of bulk amorphous alloys [{( Fe 0.5 Co 0.5)0.75 B 0.2 Si 0.05}96 Nb 4]100-x Cu x (x = 0, 1, 2, and 3). A copper mould casting of molten alloy was used to obtain a vitrified alloy in form of thin rods (1–2 mm diameter). Amorphous structure retains at a cooling rate as low as 100 K/s in argon atmosphere. Heat out-put measured in terms of a differential scanning calorimetric signal during heating and cooling cycles of these alloys demonstrate irreversibility in a compositional dependent melting point, which follows the glass transition temperature and successive crystallization. The irreversibility persists in this specific example of the bulk amorphous alloys even on sufficiently slow heating or cooling rates such as 0.33 K/s in argon. The copper inclusion tailors the melting point, the enthalpy of the fusion, and other thermodynamic parameters. Results are analyzed in corroboration to the magnetic properties.


2012 ◽  
Vol 188 ◽  
pp. 11-14
Author(s):  
Dragoş Buzdugan ◽  
Cosmin Codrean ◽  
Mircea Vodǎ ◽  
Viorel Aurel Şerban

This paper presents a mathematical model that describes the influence of the chemical composition on the glass forming ability of ferromagnetic alloys. Glass forming ability is given by the difference between the glass transition temperature and the primary crystallization temperature of the alloy. The glass forming ability is better as long this difference has a higher value. These temperatures were determined using differential thermal analysis.


1998 ◽  
Vol 554 ◽  
Author(s):  
A. Inoue ◽  
T. Zhang ◽  
H. Koshiba ◽  
T. Itoi

Since an amorphous phase in Au-Si system was synthesized for the first time by rapid solidification in 1960[1], a large number of amorphous alloys have been prepared by various rapid solidification techniques. As the main amorphous alloy systems, one can list up the noble metal-, Fe-, Co-, Ni-, Ti-, Zr-, Nb-, Mo-, lanthanide(Ln)-, Al- and Mg-based alloys. Among these alloy systems, Fe-[2], Co-[2] and Al-[3]based amorphous alloys have been used in application fields of magnetic and high specific-strength materials. Thus, Fe- and Co-based amorphous alloys have gained the most important position as engineering amorphous alloys. When special attention is paid to Fe-based amorphous alloys, Fe-P-C alloys were synthesized in 1967[4] as the first Febased amorphous alloy. Subsequently, engineering important (Fe,Co)-Si-B amorphous alloys have been developed in 1974[5][6], followed by the formation of (Fe,Co,Ni)-(Cr,Mo,W)-C in 1978[7], (Fe,Co,Ni)-(Zr,Hf) in 1980[8] and then (Fe,Co,Ni)-(Zr,HfNb)-B amorphous alloys in 1981[9]. The (Fe,Co)-Si-B amorphous alloys have been used in many application fields as soft magnetic materials[2]. However, after 1981, nobody have succeeded in finding a new amorphous alloy in Fe- and Co-based systems by rapid solidification from liquid phase. Besides, all these amorphous alloys have serious disadvantages that high cooling rates above 105 K/s are required for glass formation and the resulting sample thickness is limited to less than about 50 μm[ 10]. Great efforts have been devoted to find Fe- and Co-based amorphous alloys with a high thermal stability of supercooled liquid against crystallization and a high glass-forming ability (GFA). Very recently, we have succeeded in finding new ferromagnetic bulk amorphous alloys with critical sample thicknesses ranging from I to 15 mm in Fe-(AI,Ga)-(P,C,B,Si)[11]-[14], (Fe,Co,Ni)-(Zr,IHf,Nb)- B[15]-[17], (Fe,Co)-(Zr,Hf)-(Nb,Ta)-(Mo,W)-B[18], (Fe,Co)-Ln-B[19] (Ln=lanthanide metal) and (Nd,Pr)-Fe-Al[20]-[22] systems. In this review, we present the formation, thermal stability, mechanical strength and magnetic properties of these new ferromagnetic bulk amorphous alloys.


2000 ◽  
Vol 343-346 ◽  
pp. 97-102 ◽  
Author(s):  
G.J. Fan ◽  
Jürgen Eckert ◽  
W. Löser ◽  
S. Roth ◽  
Ludwig Schultz

2005 ◽  
Vol 89 (1) ◽  
pp. 122-129 ◽  
Author(s):  
J.S.C. Jang ◽  
Y.W. Chen ◽  
L.J. Chang ◽  
H.Z. Cheng ◽  
C.C. Huang ◽  
...  

2007 ◽  
Vol 449-451 ◽  
pp. 636-639 ◽  
Author(s):  
F.X. Qin ◽  
G.T. Bae ◽  
Z.H. Dan ◽  
H. Lee ◽  
N.J. Kim

2009 ◽  
Vol 409 ◽  
pp. 358-361
Author(s):  
Jozef Miškuf ◽  
Kornel Csach ◽  
Alena Juríková ◽  
Elena D. Tabachnikova ◽  
Vladimir Z. Bengus ◽  
...  

The fracture surface morphology of Fe76Ni2Si9B13 bulk amorphous alloys failed in compression at temperatures from 4.2 to 300 K was investigated. The samples were prepared by the explosive compaction technique from amorphous powder. It has been found that fracture stress decreases with temperature from 300 to 4.2 K. In this temperature range, the brittle failure prevails. The failure propagates across particles and along particle boundaries too. The fracture micromorphology is riverlike pattern with fine dimples.


2018 ◽  
Vol 54 (1) ◽  
pp. 138-138
Author(s):  
O. M. Hertsyk ◽  
M. O. Kovbuz ◽  
L. M. Boichyshyn ◽  
T. G. Pereverzeva ◽  
O. V. Reshetnyak

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