Crystallization process and magnetic property of Fe81Zr3Nb6B10 alloy

2015 ◽  
Vol 29 (31) ◽  
pp. 1550196 ◽  
Author(s):  
Y. M. Sun ◽  
W. Q. Yu ◽  
D. Long ◽  
Y. Zhang ◽  
Z. Hua

[Formula: see text] amorphous alloy was prepared by melt-spinning and annealed at various temperatures. The thermal property, microstructure and magnetic property were investigated by differential thermal analysis (DTA), X-ray diffraction (XRD) and vibrating sample magnetometer (VSM). The crystallization process of [Formula: see text] alloy is as follow: Amorphous [Formula: see text] residual amorphous [Formula: see text]-[Formula: see text]-[Formula: see text]-[Formula: see text] solid solution. Coercivity [Formula: see text] of [Formula: see text] alloy changes complexly, which abruptly deteriorates at 843 K and then softens with increasing annealing temperature [Formula: see text].

2014 ◽  
Vol 28 (10) ◽  
pp. 1450083 ◽  
Author(s):  
W. Q. Yu ◽  
X. C. Meng ◽  
B. Zuo ◽  
Y. M. Sun ◽  
B. Li ◽  
...  

Fe 77 Co 2 Zr 9 B 10 Cu 2 alloy prepared by melt-spinning was annealed at different heat treatment conditions. The thermal property, microstructure and magnetic property of alloys were investigated by differential thermal analysis (DTA), X-ray diffraction (XRD), transmission electron microscopy (TEM) and vibrating sample magnetometer (VSM). Fe 77 Co 2 Zr 9 B 10 Cu 2 alloy as-quenched is a mixture of α- Fe ( Co ) phase, H -phase and amorphous phase. With increasing annealing temperature, the H -phase transforms to α- Fe ( Co ) phase. Coercivity (Hc) of Fe 77 Co 2 Zr 9 B 10 Cu 2 alloy annealed at 600°C for 40 min followed by furnace cooling reaches the minimum value, which is attributed to the small and homogeneous α- Fe ( Co ) grain structure.


2011 ◽  
Vol 284-286 ◽  
pp. 2090-2093 ◽  
Author(s):  
Xue Liang Xiong ◽  
Zhi Yang ◽  
Hong Yong Ouyang

The character of ilmenite was modified by pretreatment, the effect of pre-oxidation temperature and time on structure of ilmenite were investigated by X-ray diffraction(XRD) and Thermo-gravimetric/differential thermal analysis. The results indicated that new microcrystal rutile and FeTiO3·Fe2O3 solid solution were appeared on the surface of mineral below 800°C, but evident rutile crystals and pseudobrookite Fe2O3·TiO2 were appeared above 850°C with the structure of ilmenite disrupting simultaneously. The preoxidation time increased from 15min to 60min, evident microcrystal rutile and FeTiO3·Fe2O3 solid solution were appeared by degrees without structure of ilmenite breaking.


2014 ◽  
Vol 28 (20) ◽  
pp. 1450160
Author(s):  
Z. Hua ◽  
B. Zuo ◽  
Y. M. Sun ◽  
X. N. Wang ◽  
L. R. Dong ◽  
...  

Fe 78 Co 2 Zr 8 Nb 2B10-x Ge x (x = 0, 1, 2, 3) amorphous alloys were prepared by melt-spinning and annealed at different temperatures. The microstructures and magnetic property were investigated by X-ray diffraction (XRD), transmission electron microscopy (TEM) and vibrating sample magnetometer (VSM), respectively. The crystallization processes of Fe 78 Co 2 Zr 8 Nb 2 B 10 amorphous alloy at different quenching rates are similar and complex. The α- Fe ( Co ) and α- Mn type phases are observed in their initial stage of crystallization process. Hc increases with increasing annealing temperature in general. Only α- Fe ( Co ) phase is observed in the initial stage of the crystallization processes of Fe 78 Co 2 Zr 8 Nb 2 B 10-x Ge x (x = 0, 1, 2, 3) alloys. The change trend of coercivity is complex compared with Ge -free samples. The magnetic property of Fe 78 Co 2 Zr 8 Nb 2 B 7 Ge 3 is better.


2012 ◽  
Vol 26 (11) ◽  
pp. 1250088 ◽  
Author(s):  
Z. HUA ◽  
Y. M. SUN ◽  
W. Q. YU ◽  
M. B. WEI

Fe 81 Zr 9 B 10 and Fe 81 Zr 7 Nb 2 B 10 amorphous alloys were prepared by melt-spinning. The microstructures and magnetic properties of the alloys annealed at various temperatures were investigated by X-ray diffraction (XRD) and vibrating sample magnetometer (VSM). The crystallization progresses of Fe 81 Zr 9 B 10 and Fe 81 Zr 7 Nb 2 B 10 amorphous alloys are as follows: amorphous → residual amorphous + α- Fe → α- Fe + Fe 3 Zr + ZrFe 2 and amorphous → residual amorphous + α- Fe → α- Fe + Fe 2 Zr , respectively. The grain size (D) of α- Fe in Fe 81 Zr 7 Nb 2 B 10 alloy is smaller than that in Fe 81 Zr 9 B 10 alloy at every annealing stage. The change trend of specific saturation magnetization (Ms) of Fe 81 Zr 7 Nb 2 B 10 alloy with increasing annealing temperature (Ta) is the same as that of Fe 81 Zr 9 B 10 alloy. However, the change trend of coercivity (Hc) of Fe 81 Zr 7 Nb 2 B 10 alloy with increasing annealing temperature is different from that of Fe 81 Zr 9 B 10 alloy, which abruptly deteriorates at 600°C.


2012 ◽  
Vol 476-478 ◽  
pp. 1318-1321
Author(s):  
Qi Zhi Cao ◽  
Jing Zhang

Nanostructured Fe25Al57.5Ni17.5intermetallics was prepared directly by mechanical alloying (MA) in a high-energy planetary ball-mill. The phase transformations and structural changes occurring in the studied material during mechanical alloying were investigated by X-ray diffraction (XRD). Thermal behavior of the milled powders was examined by differential thermal analysis (DTA). Disordered Al(Fe,Ni) solid solution was formed at the early stage. After 50 h of milling, Al(Fe,Ni) solid solution transformed into Al3Ni2,AlFe3,AlFe0.23Ni0.77 phase. The power annealed at temperature 500 results in forming of intermetallics AlFe3 and FeNi3 after 5h milling. The nanocrystalline intermetallic compound was obtained after 500h milling.


2008 ◽  
Vol 40 (3) ◽  
pp. 333-338 ◽  
Author(s):  
S. Grujic ◽  
N. Blagojevic ◽  
M. Tosic ◽  
V. Zivanovic ◽  
J. Nikolic

Crystallization kinetics of K2O?TiO2?3GeO2 glass was investigated by differential thermal analysis (DTA). Experiments were performed on powder samples with a particle size < 0.037 mm. The glass samples were heated at different rates in the temperature range 20-750?C. The kinetic parameters, activation energy for the crystallization process, Ec and Avrami exponent, n were calculated. Powder X-ray diffraction analysis (XRD) of crystallized glass reveals the presence of crystalline K2O?TiO2?3GeO2 indicating polymorphic crystallization with interface controlled crystal growth.


2016 ◽  
Vol 5 (1) ◽  
pp. 6
Author(s):  
Budi Setiawan ◽  
Erizal Zaini ◽  
Salman Umar

Sebuah penelitian tentang sistem dispersi padat dari asiklovir dengan poloxamer 188 telah dilakukan formulasi dengan pencampuran secara fisika dengan rasio 1 : 1, 1 : 3, 1 : 5 dan dispersi padat 1 : 1, 1 : 3, 1 : 5 dan penggilingan 1:1 sebagai pembanding. Dispersi padat dibuat menggunakan metode pencairan (fusi), yang digabung dengan poloxamer 188 pada hotplate kemudian asiklovir dimasukkan ke dalam hasil poloxamer 188 lalu di kocok hingga membentuk masa homogen. Semua formula yang terbentuk termasuk asiklovir poloxamer 188 murni dianalisis karakterisasinya dengan Differential Thermal Analysis (DTA), X-ray Diffraction, Scanning Electron Microscopy (SEM), dan Fourier Transform Infrared (FTIR), kemudian pengambilan dilakukan  (penentuan kadar) mengunakan spektrofotometer UV pada panjang gelombang 257,08 nm dan uji laju disolusi dengan aquadest bebas CO2 menggunakan metode dayung. Hasil pengambilan  (penentuan kadar) menunjukkan bahwa semua formula memenuhi persyaratan farmakope Amerika edisi 30 dan farmakope Indonesia edisi 4 yaitu 95-110%. Sedangkan hasil uji laju disolusi untuk campuran fisik 1: 1, dan dispersi padat 1: 1, dan penggilingan 1: 1 menunjukkan peningkatan yang nyata dibandingkan asiklovir murni. Hal ini juga dapat dilihat dari hasil perhitungan statistik  menggunakan analisis varian satu arah  SPSS 17.


Minerals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 440
Author(s):  
Fabiana Pereira da Costa ◽  
Jucielle Veras Fernandes ◽  
Luiz Ronaldo Lisboa de Melo ◽  
Alisson Mendes Rodrigues ◽  
Romualdo Rodrigues Menezes ◽  
...  

Natural stones (limestones, granites, and marble) from mines located in northeastern Brazil were investigated to discover their potential for use in civil construction. The natural stones were characterized by chemical analysis, X-ray diffraction, differential thermal analysis, and optical microscopy. The physical-mechanical properties (apparent density, porosity, water absorption, compressive and flexural strength, impact, and abrasion) and chemical resistance properties were also evaluated. The results of the physical-mechanical analysis indicated that the natural stones investigated have the potential to be used in different environments (interior, exterior), taking into account factors such as people’s circulation and exposure to chemical agents.


1992 ◽  
Vol 267 ◽  
Author(s):  
Ana M De Andres ◽  
Isabel MuÑOZ

ABSTRACTNineteen roman ceramic sherds found near Salobreña (Granada, Spain), in the western coast of the Mediterranean Sea, as well as different ceramic clays from the surroundingsare studied. Both clays and ceramic sherds are characterizad by X-ray diffraction and spectrometry, differential thermal analysis, and scanning electron and optical microscopies. A good number of the ceramic pieces, among which some “Terrae Sigillatae”, have a composition similar to that of the local clays and, thus, have been probably manufactured at Salobreña. Only a few of them have a foreign origin. For most of them, the firing temperature was about 800-850 °C, although some have been produced at 900-1000 °C, and some others at 1000-1100 °C. It is concluded that Salobreña appearsto have been an important settlement just in the third century of the Christian era.


2007 ◽  
Vol 130 ◽  
pp. 171-174 ◽  
Author(s):  
Z. Stokłosa ◽  
G. Badura ◽  
P. Kwapuliński ◽  
Józef Rasek ◽  
G. Haneczok ◽  
...  

The crystallization and optimization of magnetic properties effects in FeXSiB (X=Cu, V, Co, Zr, Nb) amorphous alloys were studied by applying X-ray diffraction methods, high resolution transmission electron microscopy (HRTEM), resistometric and magnetic measurements. The temperatures of the first and the second stage of crystallization, the 1h optimization annealing temperature and the Curie temperature were determined for different amorphous alloys. Activation energies of crystallization process were obtained by applying the Kissinger method. The influence of alloy additions on optimization effect and crystallization processes was carefully examined.


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