scholarly journals Conditions for partial and complete crystallization suppression upon quenching from liquid state

2021 ◽  
Vol 29 (1) ◽  
pp. 45-56
Author(s):  
O. B. Lysenko ◽  
T. V. Kalinina ◽  
I. V. Zagorulko
Keyword(s):  
Cooling Rate ◽  
Metallic Glasses ◽  
Liquid State ◽  
Complete Suppression ◽  
X Ray ◽  
Amorphous Structures ◽  
Amorphous States ◽  
Significant Factors

For bulk-amorphizing alloys Мg65Сu25Y10 and Zr41,2 Тi13,8Сu12,5Ni10Ве22,5, the thickness and cooling rate of melt layers is calculated, which ensure the formation of X-ray amorphous structures typical for metallic glasses ( lC, vC ), and truly amorphous states without inclusions of «frozen-in crystallization centers» (lc*, vc* ). Correlation of the calculated values lC, vC with the known experimental estimates is C Cachieved. It is shown that both studied alloys demonstrate a predisposition to complete suppression of crystallization processes at physically correct values of the parameters lc* and vc* (10 μm; 1,3·107 K/s and 550 μm; 2,7·103 K/s for alloys based on Mg and Zr, respectively). It is concluded that the most significant factors controlling the tendency of materials to noncrystalline solidification are the decrease in the frequency of non-stationary nucleation with the increase in the rate of QLS, as well as relatively low <1018 m-3 s-1) maximum values of the rate of stationary crystallization centers formation.

Effect of Annealing temperature on the Structural and Magnetic Properties of TbxY3-xFe5O12(x = 0.0, 1.0, 2.0) Thin Films Prepared by Sol-Gel Process

2012 ◽  
Vol 501 ◽  
pp. 236-241 ◽  
Author(s):  
Ftema W. Aldbea ◽  
Noor Bahyah Ibrahim ◽  
Mustafa Hj. Abdullah ◽  
Ramadan E. Shaiboub
Keyword(s):  
Thin Films ◽  
Magnetic Properties ◽  
Room Temperature ◽  
Annealing Temperature ◽  
Sol Gel ◽  
Vibrating Sample Magnetometer ◽  
X Ray ◽  
Garnet Phase ◽  
Sol Gel Process ◽  
Amorphous Structures

Thin films nanoparticles TbxY3-xFe5O12 (x=0.0, 1.0, 2.0) were prepared by the sol-gel process followed by annealing process at various annealing temperatures of 700° C, 800° C and 900° C in air for 2 h. The results obtained from X-ray diffractometer (XRD) show that the films annealed below 900°C exhibit peaks of garnet mixed with small amounts of YFeO3 and Fe2O3. Pure garnet phase has been detected in the films annealed at 900°C. Before annealing the films show amorphous structures. The particles sizes measurement using the field emission scanning electron microscope (FE-SEM) showed that the particles sizes increased as the annealing temperature increased. The magnetic properties were measured at room temperature using the vibrating sample magnetometer (VSM). The saturation magnetization (Ms) of the films also increased with the annealing temperature. However, different behavior of coercivity (Hc) has been observed as the annealing temperature was increased.

Structure study of the chalcogens and chalcogenides by X-ray absorption fine structure

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Hiroyuki Ikemoto ◽  
Takafumi Miyanaga
Keyword(s):  
Fine Structure ◽  
Covalent Bond ◽  
Narrow Channel ◽  
Structure Study ◽  
Chain Structure ◽  
Covalent Bonds ◽  
X Ray ◽  
Absorption Fine ◽  
Amorphous States ◽  
X Ray Absorption

AbstractIn this review, we make a survey of the structure studies for the chalcogen elements and several chalcogenides in liquid, amorphous and nanosized state by using X-ray absorption fine structure (XAFS). The chalcogen elements have hierarchic structures; the chain structure constructed with the strong covalent bond as a primary structure, and the weaker interaction between chains as a secondary one. Existence of these two kinds of interactions induces exotic behaviors in the liquid, amorphous and nanosized state of the chalcogen and chalcogenides. XAFS is a powerful structure analysis technique for multi-element systems and the disordered materials, so it is suitable for the study of such as liquid, amorphous and nanosized mixtures. In section 2, the structures for the liquid state are discussed, which show the interesting semiconductor-metal transition depending on their temperatures and components. In section 3, the structure for the amorphous states are discussed. Especially, some of chalcogens and chalcogenides present the photostructural change, which is important industrial application. In section 4, the structures of nanosized state, nanoparticles and isolated chain confined into the narrow channel, are discussed. The studies of the nanoparticle and the isolated chain reveal the alternative role between the intrachain covalent bonds and the interchain interaction.

scholarly journals Inverse Design of Fe-Based Bulk Metallic Glasses Using Machine Learning

Metals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 729
Author(s):  
Junhyub Jeon ◽  
Namhyuk Seo ◽  
Hwi-Jun Kim ◽  
Min-Ha Lee ◽  
Hyun-Kyu Lim ◽  
...  
Keyword(s):  
Thermal Properties ◽  
Metallic Glasses ◽  
Alloy Composition ◽  
Relevant Literature ◽  
Bulk Metallic Glasses ◽  
X Ray Diffraction ◽  
X Ray ◽  
Ann Models ◽  
Wide Scale ◽  
Artificial Neural Network Ann

Fe-based bulk metallic glasses (BMGs) are a unique class of materials that are attracting attention in a wide variety of applications owing to their physical properties. Several studies have investigated and designed the relationships between alloy composition and thermal properties of BMGs using an artificial neural network (ANN). The limitation of the wide-scale use of these models is that the required composition is yet to be found despite numerous case studies. To address this issue, we trained an ANN to design Fe-based BMGs that predict the thermal properties. Models were trained using only the composition of the alloy as input and were created from a database of more than 150 experimental data of Fe-based BMGs from relevant literature. We adopted these ANN models to design BMGs with thermal properties to satisfy the intended purpose using particle swarm optimization. A melt spinner was employed to fabricate the designed alloys. X-ray diffraction and differential thermal analysis tests were used to evaluate the specimens.

Neutron and X-ray small-angle scattering with Fe-based metallic glasses

1988 ◽  
Vol 97 ◽  
pp. 227-230 ◽  
Author(s):  
P. Lamparter ◽  
S. Steeb ◽  
D.M. Kroeger ◽  
S. Spooner
Keyword(s):  
Metallic Glasses ◽  
Small Angle ◽  
Small Angle Scattering ◽  
X Ray ◽  
Angle Scattering

Phase Formation in FeOx-SiO2-Cu2O-ZnO-FeS System during Melts Crystallization

2010 ◽  
Vol 297-301 ◽  
pp. 602-607
Author(s):  
Evgeny N. Selivanov ◽  
R.I. Gulyaeva ◽  
N.I. Selmenskich
Keyword(s):  
Cooling Rate ◽  
Phase Formation ◽  
X Ray Diffraction ◽  
X Ray ◽  
Two Samples ◽  
And Calorimetry

The phase formation in oxide-sulphidic systems was studied with the use of X-ray diffraction, mineralography, combined thermogravimetry and calorimetry, in addition to Х-ray spectral microanalysis. The purpose of this work was to estimate the effect of cooling rate of melts in FeOx-SiO2-Cu2O-ZnO-FeS systems on structure and content of the resulting phases. Test subjects were two samples having following compositions (wt. %): I - 40.5 Fe, 2.41 S, 0.87 Cu, 3.87 Zn, 32.1 SiO2 and II - 40.7 Fe, 3.05 S, 8.55 Cu, 4.1 Zn and 19.5 SiO2. Cooling rate of the melts was changed from 0.3 up to 900оС/s.

X-ray diffraction study of the structure of various melts of the iron-germanium system in the liquid state

1978 ◽  
Vol 19 (1) ◽  
pp. 154-156
Author(s):  
V. P. Kazimirov ◽  
G. I. Batalin ◽  
E. S. Levin ◽  
V. �. Sokol'skii ◽  
V. A. Shovskii
Keyword(s):  
Diffraction Study ◽  
Liquid State ◽  
X Ray Diffraction ◽  
X Ray

scholarly journals The Structural Stability of Soft Magnetic Fe-Co-Zr-W-B Metallic Glasses Investigated by the in-situ X-ray Diffraction

2014 ◽  
Vol 126 (1) ◽  
pp. 66-67
Author(s):  
S. Michalik ◽  
J. Bednarcik ◽  
P. Pawlik ◽  
R. Matija ◽  
P. Sovak
Keyword(s):  
Structural Stability ◽  
Metallic Glasses ◽  
X Ray Diffraction ◽  
Soft Magnetic ◽  
X Ray

Morphology and Intermetallic Study of (Sn-8Zn-3Bi)-1Ni Solder under Liquid State Aging

2015 ◽  
Vol 1087 ◽  
pp. 162-166
Author(s):  
Nor Aishah Jasli ◽  
Hamidi Abd Hamid ◽  
Ramani Mayappan
Keyword(s):  
Liquid State ◽  
Copper Substrate ◽  
Lead Free ◽  
Lead Free Solder ◽  
Reflow Time ◽  
Intermetallic Formation ◽  
X Ray ◽  
Ni Addition ◽  
Free Solder ◽  
Scanning Electron

This study investigated the effect of Ni addition on intermetallic formation in the Sn-8Zn-3Bi solder under liquid state aging. The intermetallic compounds were formed by reacting the solder alloy with copper substrate. Different reflow time was used at temperature 220°C. Morphology of the phases formed was observed using scanning electron microscope (SEM) and in order to determine elemental compositions of the phases, energy dispersive x-ray (EDX) was used. The formation of the reaction layer led by Cu5Zn8 intermetallic and then followed by Cu6Sn5 and Cu3Sn when reflow time increases. Keywords: lead free solder, intermetallic, Cu5Zn8, Cu6Sn5, liquid state aging.

Sign in / Sign up

Export Citation Format

Share Document