scholarly journals Effect of microstructure on the magnetostriction properties of Fe81Ga19−Al alloys obtained by melt spinning

2022 ◽  
Vol 145 ◽  
pp. 111559
Author(s):  
Te Yao ◽  
Pei Gong ◽  
Hua Li ◽  
Zongying Wei ◽  
Xiao Li ◽  
...  
2010 ◽  
Vol 667-669 ◽  
pp. 87-90
Author(s):  
Małgorzata Lewandowska ◽  
Henryk Dybiec ◽  
Mariusz Kulczyk ◽  
Jerzy Latuch ◽  
Krzysztof J. Kurzydlowski

The aim of the present work was to compare microstructures and mechanical properties of nano-Al alloys fabricated by two different methods: (i) SPD induced grain refinement, (ii) plastic consolidation of nano-powders or nano-crystalline ribbons. SPD grain refinement has been implemented by hydrostatic extrusion, HE. The ribbons were rapidly solidified using a melt spinning methods. Plastic consolidation of powder and ribbons was conducted by warm extrusion. The results of the studies show that by applying various fabrication routes for a given chemical composition, diverse nano-structures can be obtained, which differ in terms of grain size and shape, grain boundary character and dislocation density. As a result, the alloys also differ significantly in the mechanical properties. The findings are discussed in terms of the possibilities for optimizing properties of the bulk-nano-metals.


1985 ◽  
Vol 58 ◽  
Author(s):  
K. Aoki ◽  
K. Hiraga ◽  
T. Masumoto

ABSTRACTTi-Ni-Al alloys were rapidly quenched from a molten state by the melt spinning method. Three kinds of metastable phases, namely, amorphous,nonequilibrium and quasicrystalline phases are formed in these alloys. The amorphous phase is formed in the range of 35 to 70 at% Ti and 0 to 25 at% Al. The nonequilibrium phases are formed in the composition range of 25 to 33 at% Ti. On the other hand, fine quasicrystalline phases are distributed in the amorphous matrix of the Ti-rich alloys. Crystallization temperatures and the hardness of the amorphous alloys were also examined.


Author(s):  
Rama K. Sabat ◽  
Waqas Muhammad ◽  
Raja K. Mishra ◽  
Kaan Inal

2014 ◽  
Vol 790-791 ◽  
pp. 223-228 ◽  
Author(s):  
Ildiko Peter ◽  
Béla Varga ◽  
Mario Rosso

Rapid solidification represents a very attractive approach to develop new Al alloys in an economically convenient way. The lower segregation content, refined grains, higher ultimate tensile and yield strengths combined to a good ductile properties confer to these materials an interesting position also in the so critical automotive and/or aeronautical applications. The current paper presents results of an analysis concerning Zn-Al alloys with a new metastable microcrystalline structure, where Copper has been used as alloying element. With addition of elements as Ti and B modification of the microstructure has been reached. In order to study the influence of the cooling rate on the microstructure and structural transformations castings has been realized with melt spinning technique, in both steel and sand moulds. For morphological investigations optical and scanning electron microscopy has been employed. By dilatometric analysis and X-Ray diffraction technique the thermodynamic factors, the kinetic effects, phase transformations and the volume changes related to the transformations produced at the eutectoid temperature have been monitored. For the aforementioned field of applications the most favourable composition has been chosen: based on the up to date outcomes, by modifying the original alloy with some elements a quite homogeneous structure combined with good mechanical behaviour has been obtained.


2020 ◽  
Vol 1 (2) ◽  
pp. 35-38
Author(s):  
W.Q. Yua ◽  
L.P. Lu

A series of Fe40Co40Zr8M2B10 (M=Nb, V, Cr, Ti, W, Al) alloys were prepared using melt-spinning. The thermal curve, structure and magnetic property of alloys are examined. Because of different negative heat of mixing between elements, only Fe40Co40Zr8M2B10 (M=Nb, V, Cr, Ti) alloys form amorphous structure. These amorphous alloys are annealed at different temperatures under vacuum conditions. The crystallization processes of four amorphous alloys are similar. In the primary stage of crystallization process, only α-Fe (Co) phase precipitates and Co element mainly distributes in the residual amorphous. For the four alloys after annealing at 550°C, there is a few differences in saturation magnetization (Ms) and coercivity (Hc) due to their different microstructures.


2009 ◽  
Vol 635 ◽  
pp. 75-80 ◽  
Author(s):  
Irina I. Kositsyna ◽  
V.A. Zavalishin

The methods of electron microscopy, resistometry and magnetometry are used to study ten (36-38)Co - (32-36)Ni - (27-30)Al (at. %) alloys. Cast coarse-crystalline and microcrystalline alloys made by melt spinning in a helium atmosphere are considered. It is shown that the martensite start temperature Ms becomes 30-50°C lower as grains are refined to 1 m m. Replacement of 1 at. % cobalt by nickel and 1 at. % aluminum by nickel makes the temperature interval of the В2«L10 martensite transformation (30-60)°C and (100-110)°C higher respectively. The martensite transformation hysteresis is about 100 degrees. The melt-spun Co38Ni34Al28 alloy with the transformation temperatures Мs = 31°С, Мf = –34°С, Аs = –6°С, Аf = 70°С and Тс = 98°С is a material possessing the magnetically controlled shape memory effect.


2014 ◽  
Vol 372 ◽  
pp. 27-32 ◽  
Author(s):  
J.A. García ◽  
J. Carrizo ◽  
L. Elbaile ◽  
D. Lago-Cachón ◽  
M. Rivas ◽  
...  

Author(s):  
K. Kuroda ◽  
Y. Tomokiyo ◽  
T. Kumano ◽  
T. Eguchi

The contrast in electron microscopic images of planar faults in a crystal is characterized by a phase factor , where is the reciprocal lattice vector of the operating reflection, and the lattice displacement due to the fault under consideration. Within the two-beam theory a planar fault with an integer value of is invisible, but a detectable contrast is expected when the many-beam dynamical effect is not negligibly small. A weak fringe contrast is also expected when differs slightly from an integer owing to an additional small displacement of the lattice across the fault. These faint contrasts are termed as many-beam contrasts in the former case, and as ε fringe contrasts in the latter. In the present work stacking faults in Cu-Al alloys and antiphase boundaries (APB) in CuZn, FeCo and Fe-Al alloys were observed under such conditions as mentioned above, and the results were compared with the image profiles of the faults calculated in the systematic ten-beam approximation.


Author(s):  
Raja K. Mishra

The discovery of a new class of permanent magnets based on Nd2Fe14B phase in the last decade has led to intense research and development efforts aimed at commercial exploitation of the new alloy. The material can be prepared either by rapid solidification or by powder metallurgy techniques and the resulting microstructures are very different. This paper details the microstructure of Nd-Fe-B magnets produced by melt-spinning.In melt spinning, quench rate can be varied easily by changing the rate of rotation of the quench wheel. There is an optimum quench rate when the material shows maximum magnetic hardening. For faster or slower quench rates, both coercivity and maximum energy product of the material fall off. These results can be directly related to the changes in the microstructure of the melt-spun ribbon as a function of quench rate. Figure 1 shows the microstructure of (a) an overquenched and (b) an optimally quenched ribbon. In Fig. 1(a), the material is nearly amorphous, with small nuclei of Nd2Fe14B grains visible and in Fig. 1(b) the microstructure consists of equiaxed Nd2Fe14B grains surrounded by a thin noncrystalline Nd-rich phase. Fig. 1(c) shows an annular dark field image of the intergranular phase. Nd enrichment in this phase is shown in the EDX spectra in Fig. 2.


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