High-Energy Mechanical Grinding to Produce Cr2AlC and Ti2AlC Max Phases

2021 ◽  
Author(s):  
Yu.M. Solonin ◽  
M.P. Savyak ◽  
M.A. Vasilkivska ◽  
V.I. Ivchenko
Keyword(s):  
High Energy ◽  
Mechanical Grinding ◽  
Max Phases

scholarly journals The Magnetic and Structural Properties of the Alloys of Iron Produced by Mechanical Alloying

2020 ◽  
Vol 5 (1) ◽  
Keyword(s):  
High Energy ◽  
Second Step ◽  
X Ray Diffraction ◽  
Mechanical Grinding ◽  
Soft Magnetic ◽  
Magnetic Systems ◽  
Maximum Value ◽  
Magnetically Hard ◽  
Average Size ◽  
Complete Formation

In this study, nanostructured powders, (Fe65Co35) 100-x Crx with (x=0, 10), were synthesized by a high-energy mechanical grinding process, usually used to obtain soft magnetic systems. For this purpose, the metal elements Fe, Co and Cr, of respective purities 99.9, 99.8 and 99.5% and of average size less than one hundred microns, were milled at different times, ranging from 1 hour to 36 hours. In a second step, the nanopowders obtained were characterized by several techniques, namely X-ray diffraction (XRD), scanning electron microscopy (SEM) and vibrating sample magnetometer (VSM) techniques. The analysis of the results obtained showed the complete formation of the (Fe65Co35) and (Fe65Co35) 90Cr10 phases from 12 hours of grinding. For (Fe65Co35), the remnant field Br and the saturation magnetization Ms have similar evolutions namely, a decrease between 8h and 24h, followed by an increase until the end of the grinding. In addition, the high values of Br and Hc suggest that this system is magnetically hard. The presence of chrome in the ternary (Fe65Co35) 90Cr10 amplifies the maximum value of Hc, while maintaining a similar behavior.

scholarly journals Study of The Influence of Chromium on A Cobalt Iron Alloy

2020 ◽  
Author(s):  
smain mebrek ◽  
mourad zergoug ◽  
nacereddine haine
Keyword(s):  
Eddy Currents ◽  
Iron Alloy ◽  
High Energy ◽  
Second Step ◽  
X Ray Diffraction ◽  
Mechanical Grinding ◽  
Cobalt Iron ◽  
Micro Deformation ◽  
Grinding Time ◽  
Electrical Study

Abstract The present work comes within the framework of research of new materials, with improved properties, which could be an important key for innovative applications. For this purpose, two types of alloys, a binary (Fe, Co) and a ternary (Fe, Co, Cr), were first synthesized by mechanical grinding at high energy, varying the grinding time. In a second step, all the samples were subjected to various characterizations, a structural study (X-ray diffraction), a morphological study (scanning electron microscopy "SEM"), a magnetic characterization (the "VSM" vibrating sample magnetometer And finally, an electrical study (eddy currents). Numerous and valuable information was then deduced to know the variations in the average lens size, the internal micro deformation, the cell parameter, the saturation magnetization, the remnant field, the coercive field as well as the Z impedance, according to a only parameter, the grinding time.

scholarly journals Properties of cellulose nanofibril produced from wet ball milling after enzymatic treatment vs. mechanical grinding of bleached softwood kraft fibers

BioResources ◽  
2020 ◽  
Vol 15 (2) ◽  
pp. 3809-3820
Author(s):  
Jinsong Zeng ◽  
Lu Liu ◽  
Jinpeng Li ◽  
Jiran Dong ◽  
Zheng Cheng
Keyword(s):  
Ball Milling ◽  
Milling Time ◽  
High Efficiency ◽  
Crystallinity Index ◽  
High Energy ◽  
Degree Of Polymerization ◽  
Cellulose Nanofibril ◽  
Mechanical Grinding ◽  
Softwood Kraft Pulp ◽  
Ball Milling Time

Cellulose nanofibril (CNF) is a class of promising and renewable nanocellulosic material due to its unique dimensional characteristics and appealing properties. CNF preparations based on TEMPO pretreatment followed by high-pressure homogenization have been studied intensively, while the high energy consumption and the environmental issues remain challenges to their application. Mechanical refining processes have been commonly applied at the academic and industrial relevant scales for CNF production. In this study, bleached softwood kraft pulp was subjected to high-efficiency wet ball milling (following enzymatic pretreatment) and mechanical grinding to obtain CNF. The effects of ball milling time, grinding gap, and grinding passes on structure and properties of CNF were evaluated. Scanning electron microscopy images confirmed that the diameter of CNF was decreased with the increment of ball milling time and number of grinding passes. The results indicated that ball milling time, grinding gap, and grinding passes were important to increase the dispersity of CNF suspensions. The degree of polymerization and crystallinity index of CNF decreased with increasing ball milling time and grinding passes.

Improvement of Residual Sugar Cane Bagasse Ash by Mechanical Grinding

2014 ◽  
Vol 600 ◽  
pp. 597-605
Author(s):  
Fernandes Filho Primo ◽  
Sandro Marden Torres ◽  
Normando Perazzo Barbosa ◽  
Maria de Arruda Magalhães Vivian ◽  
Andressa de Araújo Porto Vieira
Keyword(s):  
Specific Surface ◽  
Sugar Cane ◽  
Ball Mill ◽  
High Energy ◽  
Sugar Cane Bagasse ◽  
Mechanical Grinding ◽  
X Ray ◽  
Residual Sugar ◽  
Mineralogical Characteristics ◽  
Sugar Cane Bagasse Ash

This study investigated the effect of mechanical grinding of the residual sugar cane bagasse ash on its theoretical reactive capacity. The independent variables were: type of ball mill (rotary and centrifugal crusher), and milling time. The analyzed dependent variables were: specific surface, by Blaine equipment; and mineralogy, assessed by X-ray diffraction and infrared. The results indicate that the specific surface of the ball mill type centrifugal crusher was more efficient than the rotary, achieving an increase of 500% for an optimal grinding time of 60 min. The diffraction spectra X-ray and infrared were not altered due to the grinding process. Despite the degree of finess increase, it can be concluded that the used milling conditions were not able to modify their mineralogical characteristics. Both refinement processes were capable of enhancing the material reactivity while provided a significant increase in its specific surface. Longer milling times becomes unnecessary, because would cause little change in size distribution curve, at a high energy cost.

The E-ring: interactions with plasma and implications for its evolution

1984 ◽  
Vol 75 ◽  
pp. 599-602
Author(s):  
T.V. Johnson ◽  
G.E. Morfill ◽  
E. Grun
Keyword(s):  
Time Scale ◽  
Particle Density ◽  
High Energy ◽  
Particle Removal ◽  
Density Region ◽  
Drag Forces ◽  
Orbit Evolution ◽  
History Of ◽  
Ring Particle ◽  
Ring Material

A number of lines of evidence suggest that the particles making up the E-ring are small, on the order of a few microns or less in size (Terrile and Tokunaga, 1980, BAAS; Pang et al., 1982 Saturn meeting; Tucson, AZ). This suggests that a variety of electromagnetic and plasma affects may be important in considering the history of such particles. We have shown (Morfill et al., 1982, J. Geophys. Res., in press) that plasma drags forces from the corotating plasma will rapidly evolve E-ring particle orbits to increasing distance from Saturn until a point is reached where radiation drag forces acting to decrease orbital radius balance this outward acceleration. This occurs at approximately Rhea's orbit, although the exact value is subject to many uncertainties. The time scale for plasma drag to move particles from Enceladus' orbit to the outer E-ring is ~104yr. A variety of effects also act to remove particles, primarily sputtering by both high energy charged particles (Cheng et al., 1982, J. Geophys. Res., in press) and corotating plasma (Morfill et al., 1982). The time scale for sputtering away one micron particles is also short, 102 - 10 yrs. Thus the detailed particle density profile in the E-ring is set by a competition between orbit evolution and particle removal. The high density region near Enceladus' orbit may result from the sputtering yeild of corotating ions being less than unity at this radius (e.g. Eviatar et al., 1982, Saturn meeting). In any case, an active source of E-ring material is required if the feature is not very ephemeral - Enceladus itself, with its geologically recent surface, appears still to be the best candidate for the ultimate source of E-ring material.

Analysis of electron-diffraction intensity profiles using a photodiode-array detection system

1983 ◽  
Vol 41 ◽  
pp. 322-323
Author(s):  
J. B. Warren
Keyword(s):  
Electron Diffraction ◽  
Diffraction Pattern ◽  
Detection System ◽  
High Energy ◽  
Photographic Emulsion ◽  
Diffraction Intensity ◽  
Silicon Photodiode ◽  
Photodiode Array Detection ◽  
Analog To Digital ◽  
Photodiode Array

Electron diffraction intensity profiles have been used extensively in studies of polycrystalline and amorphous thin films. In previous work, diffraction intensity profiles were quantitized either by mechanically scanning the photographic emulsion with a densitometer or by using deflection coils to scan the diffraction pattern over a stationary detector. Such methods tend to be slow, and the intensities must still be converted from analog to digital form for quantitative analysis. The Instrumentation Division at Brookhaven has designed and constructed a electron diffractometer, based on a silicon photodiode array, that overcomes these disadvantages. The instrument is compact (Fig. 1), can be used with any unmodified electron microscope, and acquires the data in a form immediately accessible by microcomputer.Major components include a RETICON 1024 element photodiode array for the de tector, an Analog Devices MAS-1202 analog digital converter and a Digital Equipment LSI 11/2 microcomputer. The photodiode array cannot detect high energy electrons without damage so an f/1.4 lens is used to focus the phosphor screen image of the diffraction pattern on to the photodiode array.

Observation of Superlattice Dislocations on Cube Planes in Ni3Al

1973 ◽  
Vol 31 ◽  
pp. 174-175 ◽  
Author(s):  
J. M. Oblak ◽  
W. H. Rand
Keyword(s):  
Nearest Neighbor ◽  
Antiphase Boundary ◽  
Nearest Neighbors ◽  
High Energy ◽  
Cross Slip ◽  
Octahedral Plane ◽  
Trapping Mechanism ◽  
Slip Traces

The energy of an a/2 <110> shear antiphase. boundary in the Ll2 expected to be at a minimum on {100} cube planes because here strue ture is there is no violation of nearest-neighbor order. The latter however does involve the disruption of second nearest neighbors. It has been suggested that cross slip of paired a/2 <110> dislocations from octahedral onto cube planes is an important dislocation trapping mechanism in Ni3Al; furthermore, slip traces consistent with cube slip are observed above 920°K.Due to the high energy of the {111} antiphase boundary (> 200 mJ/m2), paired a/2 <110> dislocations are tightly constricted on the octahedral plane and cannot be individually resolved.

Microfabrication research at the National Submicron Facility

1983 ◽  
Vol 41 ◽  
pp. 86-89
Author(s):  
E.D. Wolf
Keyword(s):  
Integrated Circuits ◽  
Particle Physics ◽  
High Speed ◽  
New Technology ◽  
High Energy ◽  
High Energy Particle ◽  
New Science ◽  
Wide Range ◽  
Intermediate Domain ◽  
Circuit Function

Most microelectronics devices and circuits operate faster, consume less power, execute more functions and cost less per circuit function when the feature-sizes internal to the devices and circuits are made smaller. This is part of the stimulus for the Very High-Speed Integrated Circuits (VHSIC) program. There is also a need for smaller, more sensitive sensors in a wide range of disciplines that includes electrochemistry, neurophysiology and ultra-high pressure solid state research. There is often fundamental new science (and sometimes new technology) to be revealed (and used) when a basic parameter such as size is extended to new dimensions, as is evident at the two extremes of smallness and largeness, high energy particle physics and cosmology, respectively. However, there is also a very important intermediate domain of size that spans from the diameter of a small cluster of atoms up to near one micrometer which may also have just as profound effects on society as “big” physics.

Void-Lattice Formation in Natural Fluorite by Electron Irradiation

1976 ◽  
Vol 34 ◽  
pp. 614-615 ◽  
Author(s):  
L.E. Murr
Keyword(s):  
Electron Microscope ◽  
Electron Irradiation ◽  
Heavy Ion ◽  
High Energy ◽  
Stoichiometric Ratio ◽  
Direct Observations ◽  
Transmission Electron ◽  
Anion Vacancies ◽  
Cation And Anion Vacancies ◽  
Lattice Formation

The production of void lattices in metals as a result of displacement damage associated with high energy and heavy ion bombardment is now well documented. More recently, Murr has shown that a void lattice can be developed in natural (colored) fluorites observed in the transmission electron microscope. These were the first observations of a void lattice in an irradiated nonmetal, and the first, direct observations of color-center aggregates. Clinard, et al. have also recently observed a void lattice (described as a high density of aligned "pores") in neutron irradiated Al2O3 and Y2O3. In this latter work, itwas pointed out that in order that a cavity be formed,a near-stoichiometric ratio of cation and anion vacancies must aggregate. It was reasoned that two other alternatives to explain the pores were cation metal colloids and highpressure anion gas bubbles.Evans has proposed that void lattices result from the presence of a pre-existing impurity lattice, and predicted that the formation of a void lattice should restrict swelling in irradiated materials because it represents a state of saturation.

High energy resolution spectrometer for the dedicated STEM

1984 ◽  
Vol 42 ◽  
pp. 558-559 ◽  
Author(s):  
P.E. Batson
Keyword(s):  
Collection Efficiency ◽  
Core Loss ◽  
Beam Current ◽  
High Energy ◽  
High Energy Resolution ◽  
Acquisition Time ◽  
Good Definition ◽  
Loss Analysis ◽  
Definition Of ◽  
Acceleration Voltage

Use of the STEM to obtain precise electronic information has been hampered by the lack of energy loss analysis capable of a resolution and accuracy comparable to the 0.3eV energy width of the Field Emission Source. Recent work by Park, et. al. and earlier by Crewe, et. al. have promised magnetic sector devices that are capable of about 0.75eV resolution at collection angles (about 15mR) which are great enough to allow efficient use of the STEM probe current. These devices are also capable of 0.3eV resolution at smaller collection angles (4-5mR). The problem that arises, however, lies in the fact that, even with the collection efficiency approaching 1.0, several minutes of collection time are necessary for a good definition of a typical core loss or electronic transition. This is a result of the relatively small total beam current (1-10nA) that is available in the dedicated STEM. During this acquisition time, the STEM acceleration voltage may fluctuate by as much as 0.5-1.0V.

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