scholarly journals IMPORTANCE OF DIFFUSION PUMPING WHILE PRODUCING AMORPHOUS AND PARTIALLY CRYSTALLISED MATERIALS

2021 ◽  
Vol 6 (3) ◽  
pp. 157-161
Author(s):  
Marcin NABIAŁEK ◽  
Bartosz PŁOSZAJ

It can be state that 1960 was the year when amorphous materials era began. 1989 was the year when bulk materials amorphous were first produced. Since then researchers around the World try to improve or find new correlations according to this group of materials. Sometimes instead of obtaining amorphous materials produced sample may be partially crystallised. During last research, ingots of two different alloys discussed in this work were produced with and without use of diffusion pump. Samples produced in injection method were done under the same condition for both cases of ingots. Then samples were subjected to structure analysis with the use of x-rays and were checked according to magnetic properties. Obtained results are compatible with expectations, however by meet one give promising possibility of further research.

Author(s):  
A.R. Pelton ◽  
A.F. Marshall ◽  
Y.S. Lee

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.


Nano Research ◽  
2021 ◽  
Author(s):  
Alevtina Smekhova ◽  
Alexei Kuzmin ◽  
Konrad Siemensmeyer ◽  
Chen Luo ◽  
Kai Chen ◽  
...  

AbstractModern design of superior multi-functional alloys composed of several principal components requires in-depth studies of their local structure for developing desired macroscopic properties. Herein, peculiarities of atomic arrangements on the local scale and electronic states of constituent elements in the single-phase face-centered cubic (fcc)- and body-centered cubic (bcc)-structured high-entropy Alx-CrFeCoNi alloys (x = 0.3 and 3, respectively) are explored by element-specific X-ray absorption spectroscopy in hard and soft X-ray energy ranges. Simulations based on the reverse Monte Carlo approach allow to perform a simultaneous fit of extended X-ray absorption fine structure spectra recorded at K absorption edges of each 3d constituent and to reconstruct the local environment within the first coordination shells of absorbers with high precision. The revealed unimodal and bimodal distributions of all five elements are in agreement with structure-dependent magnetic properties of studied alloys probed by magnetometry. A degree of surface atoms oxidation uncovered by soft X-rays suggests different kinetics of oxide formation for each type of constituents and has to be taken into account. X-ray magnetic circular dichroism technique employed at L2.3 absorption edges of transition metals demonstrates reduced magnetic moments of 3d metal constituents in the sub-surface region of in situ cleaned fcc-structured Al0.3-CrFeCoNi compared to their bulk values. Extended to nanostructured versions of multicomponent alloys, such studies would bring new insights related to effects of high entropy mixing on low dimensions.


1999 ◽  
Vol 196-197 ◽  
pp. 35-36
Author(s):  
M. Tejedor ◽  
J.A. García ◽  
J. Carrizo ◽  
L. Elbaile ◽  
J.D. Santos

Minerals ◽  
2018 ◽  
Vol 8 (8) ◽  
pp. 311 ◽  
Author(s):  
Carlotta Giacobbe ◽  
Jonathan Wright ◽  
Dario Di Giuseppe ◽  
Alessandro Zoboli ◽  
Mauro Zapparoli ◽  
...  

Nowadays, due to the adverse health effects associated with exposure to asbestos, its removal and thermal inertization has become one of the most promising ways for reducing waste risk management. Despite all the advances in structure analysis of fibers and characterization, some problems still remain that are very hard to solve. One challenge is the structure analysis of natural micro- and nano-crystalline samples, which do not form crystals large enough for single-crystal X-ray diffraction (SC-XRD), and their analysis is often hampered by reflection overlap and the coexistence of multiple fibres linked together. In this paper, we have used nano-focused synchrotron X-rays to refine the crystal structure of a micrometric tremolite fibres from Val d’Ala, Turin (Italy) after various heat treatment. The structure of the original fibre and after heating to 800 °C show minor differences, while the fibre that was heated at 1000 °C is recrystallized into pyroxene phases and cristobalite.


2015 ◽  
Vol 60 (4) ◽  
pp. 3095-3100 ◽  
Author(s):  
M. Szota

Amorphous materials in the form of tapes, despite being discovered more than half a century ago, are still the object of interest for materials engineers and electro-technical industry. They possess a great application potential, and are constantly studied for new variations. Due to the different structure from the commonly manufactured textured FeSi sheets, FeCoB based amorphous alloys demonstrate very good, so called soft magnetic properties. This paper presents the results of studying the structure and magnetic properties of tapes of Fe78CoxSi11-xB11(X = 0 or 2) alloys of amorphous structure. In addition, the effect of Co alloy addition on the type of structural defects in the area of ferromagnetic saturation approach was examined. It was found that a small addition of Co affects the increase of saturation magnetization value, as well as the distribution of magnetization vectors within the stresses sources in form of structure defects.


2020 ◽  
Vol 1 (1-2) ◽  
pp. 83-87
Author(s):  
A. P. Lutay ◽  
P. V. Kurenkov

The device of flexitanks, as well as technical and technological features of the transportation of goods with their use, are considered. The relevance of the topic is due to the fact that at present almost 80 % of international transit in the world takes place in containers, on the domestic markets of the largest countries of the world, goods flows also go mainly in containers. Flexitanks are studied as innovative tools for organizing the chains of delivery of goods and goods in containers, having all the necessary equipment for transporting various kinds of cargo.Analytical and marketing methods are applied, taking into account the principles of the theory of logistics, logic, as well as shared materials.A comparison of this type of packaging with other transportation means is presented. It was revealed that flexitara is more oriented to non-hazardous liquid cargo in terms of its characteristics. The use of flexitanks allows to reduce transportation costs, reduce labor, time and transportation costs, as well as to carry out multimodal transportation using various modes of transport.It is established that flexitanks can act as a full-fledged and multi-functional alternative to tanks, tank containers and other containers for transporting bulk materials that are non-hazardous cargoes. The use of technology for the transportation of goods in flexitanks will contribute to the further innovative development of multi-modal freight transportation and the growth of containerization of goods exchange in general. 


2005 ◽  
Vol 20 (3) ◽  
pp. 563-566 ◽  
Author(s):  
Tetsuji Saito ◽  
Hiroyuku Takeishi ◽  
Noboru Nakayama

We report a new compression shearing method for the production of bulk amorphous materials. In this study, amorphous Nd–Fe–B melt-spun ribbons were successfully consolidated into bulk form at room temperature by the compression shearing method. X-ray diffraction and transmission electron microscopy studies revealed that the amorphous structure was well maintained in the bulk materials. The resultant bulk materials exhibited the same magnetic properties as the original amorphous Nd–Fe–B materials.


2014 ◽  
Vol 70 (a1) ◽  
pp. C139-C139 ◽  
Author(s):  
Michelle Alvarez-Murga ◽  
Pierre Bleuet ◽  
Christophe Lepoittevin ◽  
Nathalie Boudet ◽  
Gaston Gabarino ◽  
...  

By suitably combining diffraction/scattering and tomography (DSCT), it is possible to access to selective submicron 2D/3D structural and micro-structural information, which cannot be obtained from separate, independent diffraction and tomography experiments. DSCT is used to discriminate between multi-phase crystalline and amorphous materials, especially when the similarities in densities limit the use of other methods. In addition, this method is sensitive to local variation of the crystalline state, texture, grain size or strains inside the object and can allow simultaneous 3D mappings of such properties. The DSCT phase-selectivity can be easily combined with fluorescence and absorption for added chemical and density resolution allowing multi-modal analyses. As samples can be used in their original state, this method can be applied without cutting or polishing them. Moreover the setup can be adapted with specific sample environments in order to monitor phase and microstructure evolution as a function of an externally controlled parameter with a non-invasive approach. After a first report on in 1998 [1], since 2008 capabilities of DSCT have been demonstrated using x-rays on complex materials as diverse as biological tissue, pigments, Portland cements, Carbon-based materials, Uranium-based nuclear fuel, Ni/Al2O3 catalysts or amorphous systems [2]. More recently, the technique has evolved towards quantitative characterization of the microstructure and stress/strain through either Rietveld or Peak Profile analyses and also pair distribution function techniques (PDF) and their application to nanostructured materials [3]. In this poster contribution, we briefly review the principle and methodology of pencil-beam based x-ray DSCT which is two-fold: (i) selective structural imaging and (ii) extraction of selective scattered patterns of ultra-minor phases.


Sign in / Sign up

Export Citation Format

Share Document