Preparation of Nanostructured Al-4.5wt%Mg Powder via Mechanical Alloying Process

2011 ◽  
Vol 13 ◽  
pp. 1-5 ◽  
Author(s):  
Ali Shokuhfar ◽  
Omid Ozhdelnia ◽  
Ali Mostaed ◽  
Ehsan Mostaed
Keyword(s):  
Electron Microscopy ◽  
Mechanical Alloying ◽  
Crystallite Size ◽  
Weight Ratio ◽  
Milled Powder ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Ma Process ◽  
Xrd And Tem

In this work, the preparation of nanostructured Al-4.5wt%Mg powder through the mechanical alloying (MA) process was evaluated. The X-ray diffraction (XRD) technique was used to calculate the crystallite size and microstrain. Scanning electron microscopy (SEM) was used not only to study the morphology of the powders but also to show the fact that the Mg powders were distributed during the MA process. Transmission electron microscopy (TEM) was also used to demonstrate whether the produced powders are nanostructured or not. XRD results showed that microstrain and crystallite size of milled powder (after 10 h milling at the ball-to-powder weight ratio (BPR) of 20:1) were ≈-0.34% and ≈20nm respectively. XRD and TEM results showed that Al12Mg17has been formed during MA process. This means that during this process, mutual diffusion of Al and Mg has occurred.

Investigation the Structural and Magnetic Properties of FINEMET Type Alloy Produced by Mechanical Alloying

2014 ◽  
Vol 970 ◽  
pp. 252-255 ◽  
Author(s):  
Tayebeh Gheiratmand ◽  
Saeed Mohammadi Siyani ◽  
Hamid Reza Madaah Hosseini ◽  
Parviz Davami
Keyword(s):  
Electron Microscopy ◽  
Solid Solution ◽  
Mechanical Alloying ◽  
Milled Powder ◽  
Main Peak ◽  
X Ray Diffraction ◽  
Type Alloy ◽  
Mechanically Alloyed ◽  
X Ray ◽  
Transmission Electron

In this research, FINEMET alloy with composition of Fe73.5Si13.5B9Nb3Cu1was produced by mechanical alloying from elemental powders. The effect of milling time on the magnetic and structural properties of alloy has been investigated using X-ray diffraction, scanning electron microscopy, transmission electron microscopy and vibrating sample magnetometery. The results showed that milling for 53 hr leads to the formation of Fe supersaturated solid solution which includes Si, B and Nb atoms with mean crystallite size of ~30 nm. The shift of the main peak of Fe to the higher angles indicated that Si and B atoms dissolve in the Fe solid solution, at primary stage of mechanical alloying, up to the 42 hr while Nb atoms dissolve at final stages. The magnetization of milled powder for 53 hr was 173.7 emu/g, almost the same as that of the melt-spun ribbon. In addition; the coercivity reached to 15.5 Oe after 53 hr of milling. The higher value of coercivity in mechanically alloyed samples is attributed to strains induce to the structure during milling and the lack of amorphous phase and exchange interaction between nanograins.

scholarly journals Quartz Crystallite Size and Moganite Content as Indicators of the Mineralogical Maturity of the Carboniferous Chert: The Case of Cherts from Eastern Asturias (Spain)

Minerals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 611
Author(s):  
Celia Marcos ◽  
María de Uribe-Zorita ◽  
Pedro Álvarez-Lloret ◽  
Alaa Adawy ◽  
Patricia Fernández ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Crystallite Size ◽  
Archaeological Sites ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Infrared And Raman Spectroscopy ◽  
First Time ◽  
Geological Formations

Chert samples from different coastal and inland outcrops in the Eastern Asturias (Spain) were mineralogically investigated for the first time for archaeological purposes. X-ray diffraction, X-ray fluorescence, transmission electron microscopy, infrared and Raman spectroscopy and total organic carbon techniques were used. The low content of moganite, since its detection by X-ray diffraction is practically imperceptible, and the crystallite size (over 1000 Å) of the quartz in these cherts would be indicative of its maturity and could potentially be used for dating chert-tools recovered from archaeological sites. Also, this information can constitute essential data to differentiate the cherts and compare them with those used in archaeological tools. However, neither composition nor crystallite size would allow distinguishing between coastal and inland chert outcrops belonging to the same geological formations.

Synthesis and Evaluations of Microstructure Properties on Al-(50, 60, 70 mass%)Si Systems by Mechanical Alloying

2004 ◽  
Vol 449-452 ◽  
pp. 249-252 ◽  
Author(s):  
Jung Il Lee ◽  
Tae Whan Hong ◽  
Il Ho Kim ◽  
Soon Chul Ur ◽  
Young Geun Lee ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Mechanical Alloying ◽  
Milling Time ◽  
Alloy System ◽  
Misfit Strain ◽  
X Ray Diffraction ◽  
Mechanically Alloyed ◽  
X Ray ◽  
Transmission Electron ◽  
Nanocrystalline Structures

High silicon Al-Si alloy powders having nanocrystalline structures have been produced by mechanical alloying process. Microstructures in mechanically alloyed Al-Si powders were investigated by scanning electron microscopy and transmission electron microscopy. X-ray diffraction analyses were also carried out to characterize lattice constant, crystallite size and misfit strain. Effective milling time for the formation of nanocrystalline microstructure was thought to be approximately 12 hours, and the sizes of Al and Si crystallites in mechanically alloyed powders after longer than 12 hours of milling were reduced to about 30nm and 70nm respectively, in Al-70 mass% Si alloy system. The misfit strains increased with milling time up to 240 hours, and saturated to 5.73×10-3 and 4.39×10-3 for Al and Si crystallites, respectively.

Evaluations of Microstructure and Hydrogenation Properties on Mg2NiHx Hydrogen Absorbing Alloys by Hydrogen Induced Mechanical Alloying

2007 ◽  
Vol 544-545 ◽  
pp. 311-314 ◽  
Author(s):  
Whan Gi Kim ◽  
Soon Chul Ur ◽  
Y.G. Lee ◽  
Young Jig Kim ◽  
Tae Whan Hong
Keyword(s):  
Electron Microscopy ◽  
Mechanical Alloying ◽  
High Efficiency ◽  
Misfit Strain ◽  
Mass Ratio ◽  
Hydrogen Storage Materials ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Pressure Hydrogen

In order to fabricate high efficiency, light-weight hydrogen storage materials in an economical way, we have been made to propose a new mechanical alloying process by high-pressure hydrogen induced planetary ball milling(HIMA) using Mg and Ni chips. Microstructural evaluations of the Mg-Ni-H systems synthesized were investigated by scanning electron microscopy and the transmission electron microscopy. X-ray diffraction analysis was also made to characterize the lattice constant, crystallite size and misfit strain. The hydrogenation properties of the particles synthesized were evaluated by automatic PCI (pressure-composition-isotherm). Adopting 66:1 BCR (ball to chips mass ratio) for HIMA process, fully hydrogenated alloys were obtained after 96 hrs of milling, resulting in total hydrogen content of 2.25 mass%.

The structural transformation of anatase TiO2 by high-energy vibrational ball milling

1999 ◽  
Vol 14 (3) ◽  
pp. 841-848 ◽  
Author(s):  
Suchitra Sen ◽  
M. L. Ram ◽  
S. Roy ◽  
B. K. Sarkar
Keyword(s):  
Electron Microscopy ◽  
Ball Milling ◽  
Structural Transformation ◽  
Milled Powder ◽  
High Energy ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
First Time ◽  
Pressure Phase

The structural transformation of anatase TiO2 by high-energy vibrational ball milling was studied in detail by different analytical methods of x-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). This structural transformation involves both phase transition and nanoparticle formation, and no amorphization was observed. The crystallite size was found to decrease with milling time down to nanometer size ∼13 nm and approaching saturation, accompanied by phase transformation to metastable phases, i.e., TiO2(II), which is a high-pressure phase and TiO2(B), which was identified in ball-milled powder reported for the first time in this paper. These phases eventually started transforming to rutile by further milling.

Structural Evolution of the Cu-Ni Solid Solution Formed by Ball Mechanical Alloying Treatment (BMAT)

2011 ◽  
Vol 673 ◽  
pp. 279-284 ◽  
Author(s):  
Iman Farahbakhsh ◽  
Alireza Zakeri ◽  
Palavesamuthu Manikandan ◽  
Kazuyuki Hokamoto
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Mechanical Alloying ◽  
Milling Time ◽  
Structural Evolution ◽  
Mutual Diffusion ◽  
X Ray Diffraction ◽  
X Ray ◽  
Ma Process ◽  
Scanning Electron

A nanostructured powder with uniform distribution of Ni and Cu powders was produced by means of the Ball Mechanical Alloying Treatment (BMAT). Mutual diffusion of Ni and Cu in the nanostructured layer and the microstructure of the cross section of the remaining powders were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM) and Electron Probe Microanalyzer (EPMA). X-ray diffraction patterns revealed that increasing the milling time gives rise to decreasing crystallite size and lattice parameter during the MA process. Furthermore, scanning electron microscopy (SEM) was utilized not only for evaluating the morphology and microstructure of the remaining powder particles but also for proving this claim that during MA process, the mutual diffusion of Ni and Cu has occurred. Elemental mappings also show that the alloying process occurred in samples but obtaining the uniform shape, size and microstructure of the powder requires increase in the milling time.

scholarly journals Reduction of Magnetite in the Presence of Activated Carbon Using Mechanical Alloying

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Ledwaba Harry Moloto ◽  
Sunnyboy Stanley Manzini ◽  
Ezekiel Dixon Dikio
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Activated Carbon ◽  
Mechanical Alloying ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Reduction Behaviour ◽  
Scanning Electron

The reduction behaviour of magnetite using graphite under ball-milling conditions (using a planetary mono mill, Fritsch Pulverisette 6) has been investigated. The reaction of magnetite and graphite at different milling conditions leads to the formation of Fe2+and Fe3+species, the former increasing at the expense of Fe3O4. Fe3O4completely disappeared after a ball to powder ratio of 50 : 1 and beyond. The Fe2+species were confirmed to be due to FeO using Mössbauer Spectroscopy and X-ray diffraction techniques. Scanning electron microscopy and transmission electron microscopy analyses confirm the reduction of magnetite to wüstite.

scholarly journals Síntesis de Puntos Cuánticos de SnO2 por Precipitación Química Asistida con Radiación Ultrasónica

2018 ◽  
pp. 97-101
Keyword(s):  
Electron Microscopy ◽  
Quantum Dots ◽  
Crystallite Size ◽  
Chemical Precipitation ◽  
Ultrasonic Waves ◽  
X Ray Diffraction ◽  
Rutile Structure ◽  
X Ray ◽  
Transmission Electron ◽  
Vis Spectroscopy

Síntesis de Puntos Cuánticos de SnO2 por Precipitación Química Asistida con Radiación Ultrasónica P. Alvarado1, D. Acosta2, M.M. Gomez1, J.L. Solis1,2 1 Facultad de Ciencias, Universidad Nacional de Ingeniería, Lima 25, Perú 2 Laboratorio de Películas Delgadas, Instituto de Física, UNAM, Circuito de la Investigación Científica, Ciudad Universitaria, C.P. 04510, México Recibido 8 de noviembre del 2018, Revisado el 10 de diciembre de 2018. Aceptado el 12 de diciembre de 2018 DOI: https://doi.org/10.33017/RevECIPeru2018.0015/ Resumen Puntos cuánticos de SnO2 fueron preparados vía precipitación química asistida con ondas ultrasonicas. Análisis de difracción de rayos (XRD) confirmaron la estructura tetragonal tipo rutilo de los puntos cuánticos de SnO2 con tamaño de cristalito de 1,4 nm. Las micrografías de microscopia electrónica de barrido (SEM) de la muestra en polvo obtenida muestra que los puntos cuánticos de SnO2 son partículas aglomeradas alrededor de 10 nm, mientras las imágenes de microscopia electrónica de transmisión (TEM) confirman que el tamaño del cristalito es similar a la medición realizada por difracción de rayos X (XRD). El ancho de banda de energía de los puntos cuánticos de SnO2 medida por espectroscopia UV Vis de reflexión difusa fue de 4.3 eV, mostrando un significativo desplazamiento atribuido al confinamiento cuántico. Descriptores: Puntos cuánticos, ultrasónicos. Abstract SnO2 quantum dots were prepared via chemical precipitation assisted with ultrasonic waves. X-ray diffraction analysis (XRD) confirmed the tetragonal rutile structure of quantum dots SnO2 with crystallite size of 1.4 nm. The scanning electron microscopy (SEM) micrographs of the obtained powder sample show that the SnO2 quantum dots are agglomerated particles around 10 nm, while the transmission electron microscopy (TEM) images confirm that the crystallite size is similar to the measurement made by X-ray diffraction (XRD). The energy bandwidth of the quantum dots of SnO2 measured by UV Vis spectroscopy of diffuse reflection was 4.3 eV, showing a significant displacement attributed to the quantum confinement. Keywords: Quantum points, ultrasonic.

scholarly journals Direct Fabrication of Cobalt Oxide Nanoparticles Employing Sucrose as a Combustion Fuel

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
M. Th. Makhlouf ◽  
B. M. Abu-Zied ◽  
T. H. Mansoure
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Crystallite Size ◽  
Thermal Analyses ◽  
Combustion Method ◽  
Molar Ratio ◽  
X Ray Diffraction ◽  
X Ray ◽  
Cobalt Oxide Nanoparticles ◽  
Transmission Electron

Combustion method has been used as a fast and facile method to prepare nanocrystalline Co3O4 spinel employing sucrose as a combustion fuel. The products were characterized by thermal analyses (TGA and DTA), X-ray diffraction technique (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and transmission electron microscopy (TEM) techniques. Experimental results revealed that the molar ratio of fuel/oxidizer (F/O) plays an important role in controlling the crystallite size of Co3O4 nanoparticles. Transmission electron microscopy indicated that the crystallite size of Co3O4 nanocrystals was in the range of 13–32 nm. X-ray diffraction confirmed the formation of CoO phase with spinel Co3O4. The effect of calcination temperature on crystallite size and morphology has been, also, discussed.

A High Resolution Study of G.P. Zones in Aluminum - 4.2 at % Silver

1982 ◽  
Vol 40 ◽  
pp. 722-723 ◽  
Author(s):  
R. Gronsky
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
High Resolution ◽  
Computer Simulations ◽  
Structural Characteristics ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Resolution Study

The phenomenon of clustering in Al-Ag alloys has been extensively studied since the early work of Guinierl, wherein the pre-precipitation state was characterized as an assembly of spherical, ordered, silver-rich G.P. zones. Subsequent x-ray and TEM investigations yielded results in general agreement with this model. However, serious discrepancies were later revealed by the detailed x-ray diffraction - based computer simulations of Gragg and Cohen, i.e., the silver-rich clusters were instead octahedral in shape and fully disordered, atleast below 170°C. The object of the present investigation is to examine directly the structural characteristics of G.P. zones in Al-Ag by high resolution transmission electron microscopy.

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