Behavior of Scandium in Aluminum Alloys of Different Alloying Systems

2014 ◽  
Vol 794-796 ◽  
pp. 1002-1007
Author(s):  
Boris V. Ovsyannikov ◽  
Viktor M. Zamyatin
Keyword(s):  
Chemical Composition ◽  
Aluminum Alloys ◽  
Intermetallic Compounds ◽  
Alloy Composition ◽  
Alloying Elements ◽  
Scanning Electronic Microscopy ◽  
Electronic Microscopy ◽  
Manganese Alloy ◽  
X Ray

Microstructure and composition of elements in phases of homogenized ingots in aluminum alloys of various alloying systems: Al-Mg-Mn-Si, Al-Mg-Si-Cu, and Al-Zn-Mg-Cu, were examined using a method of scanning electronic microscopy and X-ray microanalysis. Besides basic alloying elements of magnesium, zinc, copper, silicon, and manganese, alloy composition contained additional alloying elements, including zirconium and scandium. Presence of intermetallic compounds of various chemical composition insoluble during ingot homogenization was found in microstructure of examined samples. It is found that zirconium and scandium are jointly present in composition of some intermetallic compounds containing additional alloying elements of alloys.

scholarly journals IMPROVEMENT OF MICROMERITIC, COMPRESSIBILITY AND SOLUBILITY CHARACTERISTICS OF LINEZOLID BY CRYSTALLO-CO-AGGLOMERATION TECHNIQUE

2017 ◽  
Vol 9 (4) ◽  
pp. 47 ◽  
Author(s):  
Atul M. Kadam ◽  
Shitalkumar S. Patil
Keyword(s):  
Drug Release ◽  
Methyl Cellulose ◽  
Mechanical Deformation ◽  
Angle Of Repose ◽  
Scanning Electronic Microscopy ◽  
Electronic Microscopy ◽  
X Ray ◽  
Fourier Transformation Infrared Spectroscopy ◽  
Time Required ◽  
Good Flow

Objective: The purpose of current study was to improve physicochemical properties such as micrometric, compressibility and solubility of linezolid (LNZ) by preparing crystallo-co-agglomerates (CCA) in the presence of polymer for the enhancement of overall physicochemical performance.Methods: The process of agglomeration involves the use of dichloromethane (DCM) as a good solvent and chloroform as bridging liquid were used to prepare agglomerates. Agglomerates were characterised in the solid state using several techniques such as Scanning electronic microscopy(SEM), Fourier transformation infrared spectroscopy (FTIR), X-ray powder diffraction analysis (XRPD) The agglomerates obtained were evaluated for micrometric, mechanical, deformation, compressibility and drug release properties.Results: It was found that micrometric properties and dissolution characteristics of agglomerates were significantly improved than that of pure linezolid. Solubility was found to be increased than pure linezolid. The solubility of crystallo co-agglomerates was found an increase in 5 fold 3 fold and 3.7 fold for PVPK30 (0.5%), PVPK30 (0.25%) and PVPK30 (0.75%) respectively. The angle of repose for all batches was found between 22 ° to 30 °Carrs index was between 12.27±0.6 to 18.73±0.4 and Hausners ratio Near to 1, indicated good flow ability of agglomerates. The time required for drug release over a period of 60 min, is as LA1>LA2>LA3. LA3 shows fast drug release than LA1 and LA2, due to solubilization of drug due to more concentration of PVPK30 and less concentration of talc.Conclusion: Based on the above results, it was revealed that CCA of linezolid prepared with DCM and HPMC (Hydroxypropyl methyl cellulose)/PEG (Polyethylene glycol)/PVP (Polyvinylpyrrolidone) K30 exhibited improved micrometric properties, compressibility and in addition to improving solubility and dissolution rate.

scholarly journals The Use of Calcium Lactate to Enhance the Durability and Engineering Properties of Bioconcrete

2021 ◽  
Vol 13 (16) ◽  
pp. 9269
Author(s):  
Saddam Hussein Abo Sabah ◽  
Luis Hii Anneza ◽  
Mohd Irwan Juki ◽  
Hisham Alabduljabbar ◽  
Norzila Othman ◽  
...  
Keyword(s):  
Calcium Lactate ◽  
Engineering Properties ◽  
Optimal Conditions ◽  
Scanning Electronic Microscopy ◽  
Electronic Microscopy ◽  
Sem Images ◽  
X Ray ◽  
Predicted Values ◽  
Potential Option ◽  
Scanning Electron

This study investigated the optimization of the bioconcrete engineering properties and durability as a response of the calcium lactate (CL) content (0.22–2.18 g/L) and curing duration (7–28 days) using the response surface methodology (RSM). Scanning electronic microscopy (SEM) was conducted to evaluate the microstructure of calcium precipitated inside the bioconcrete. The results indicated that the optimal conditions for the engineering properties of concrete and durability were determined at 2.18 g/L of CL content after 23.4 days. The actual and predicted values of the compressive strength, splitting tensile strength, flexural strength, and water absorption were 43.51 vs. 43.43, 3.19 vs. 3.19, 6.93 vs. 5.50, and 7.55 vs. 7.55, respectively, with a level of confidence exceeding 95%. The scanning electron microscope (SEM) images and energy-dispersive X-ray spectroscopy (EDX) proved that the amount of calcium increased with the increase in CL content up to 2.81 g/L at 23.4 days, reducing the pores inside the concrete and making it a great potential option for healing of concrete structures.

Characterization of Shivirtui Zeolite Modified with Aluminum Oxyhydroxide Nanofibers

2019 ◽  
Vol 942 ◽  
pp. 40-49
Author(s):  
Yulia Murashkina ◽  
Olga B. Nazarenko
Keyword(s):  
Chemical Properties ◽  
Nitrogen Adsorption ◽  
X Ray Diffraction ◽  
Scanning Electronic Microscopy ◽  
Electronic Microscopy ◽  
X Ray ◽  
Physical And Chemical ◽  
And Chemical Properties ◽  
Aluminum Oxyhydroxide

Natural zeolite of Shivirtui deposit (Russia) was modified with nanofibers of aluminum oxyhydroxide AlOOH. Aluminum oxyhydroxide nanofibers were produced at the heating and oxidation of aluminum powder with water. The properties of modified zeolite were investigated by means of X-ray diffraction, transmission electronic microscopy, scanning electronic microscopy, low-temperature nitrogen adsorption, thermal analysis, and Fourier transform infrared spectroscopy. It was found that water content in the modified sample of zeolite was about 15 %. Based on the study of the physical and chemical properties, shivirtui zeolite modified with nanofibers of aluminum oxyhydroxide can be proposed for use as a flame-retardant additive to polymers.

The Competitive Growth of BiOI and BiSI in the Solvothermal Process

2011 ◽  
Vol 236-238 ◽  
pp. 1919-1922 ◽  
Author(s):  
Wen Jun Fa ◽  
Pin Jiang Li ◽  
Yan Ge Zhang ◽  
Li Li Guo ◽  
Jia Fan Guo ◽  
...  
Keyword(s):  
Reaction Mechanism ◽  
Powder Diffraction ◽  
Energy Dispersive ◽  
Solvothermal Process ◽  
Competitive Growth ◽  
Scanning Electronic Microscopy ◽  
Electronic Microscopy ◽  
X Ray

BiOI nanolamellas and BiSI nanowires were synthesized using Bi(NO3)3·5H2O, (NH2)2CS and I2 as reactants in the solvothermal process with ethanol as the system media. The as-prepared samples were characterized by X-ray powder diffraction (XRD), scanning electronic microscopy (SEM), Energy-Dispersive X-ray Spectrometer (EDS). The competitive growth of BiOI and BiSI were investigated by changing the quantity of (NH2)2CS. A possible reaction mechanism was proposed.

scholarly journals Urea-Based Combustion Process for the Synthesis of Nanocrystalline Ni-La-Fe-O Catalysts

2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
Bahaa Abu-Zied ◽  
Abdullah M. Asiri
Keyword(s):  
Combustion Process ◽  
Catalytic Decomposition ◽  
Nitrogen Adsorption ◽  
Scanning Electronic Microscopy ◽  
Electronic Microscopy ◽  
Hydrogen Peroxide Decomposition ◽  
Calcination Process ◽  
X Ray ◽  
Peroxide Decomposition ◽  
Combustion Route

Nanocrystalline Ni-La-Fe-O catalysts having the general formula NiLaxFe2−xO4(0.00≤x≤2.00) were synthesized by the combustion route employing urea as a combustion fuel. The calcination process was affected at 500°C. The structural properties of the obtained catalysts were systematically investigated by X-ray powder diffraction (XRD), scanning electronic microscopy (SEM), energy-dispersive X-ray spectra (EDX), and nitrogen adsorption at −196°C. Crystalline NiFe2O4and La2NiO4phases were detected for the catalysts havingx=0.00and 2.00, respectively, as a result of solid-solid interaction between mixtures precursors. The activity of the obtained catalysts was checked for hydrogen peroxide decomposition at 35–55°C. A synergic effect was observed for the catalysts havingx-value of 1.00 and 1.50. Such effect was attributed to the increase in the number of the active constituents involved in the catalytic decomposition of H2O2.

Quantitative Evaluation of The Chemical Composition of γ-γ’Interfaces in Ni Superalloys

2001 ◽  
Vol 7 (S2) ◽  
pp. 264-265
Author(s):  
H. A. Calderon ◽  
M. Benyoucef ◽  
N. Clement
Keyword(s):  
Mechanical Properties ◽  
Spatial Distribution ◽  
Chemical Composition ◽  
Large Volume ◽  
Alloy Composition ◽  
Volume Fraction ◽  
Alloying Elements ◽  
Local Distribution ◽  
Strain Fields ◽  
Ni Alloys

The excellent mechanical properties of Ni based superalloys depend upon the presence of γ’ particles (LI2 structure). Their volume fraction, spatial distribution and size determine the mechanical strength of these alloys. Ni alloys for technological applications make use of large volume fractions of precipitates where processes of coarsening and coalescence take place during service leading in some cases to deterioration of properties. Addition of different alloying elements prevents accelerated coalescence by retarding diffusion and thus improving the mechanical properties of such alloys. Coalescence can also take place under the influence of an applied stress leading to the formation of rafts of the y' phase. For example the microstructure changes during creep deformation, depending on the alloy composition, with the corresponding formation of dislocation networks and rafts of different morphologies [1]. The γ-γ’ interfaces are also different depending on the alloy composition and most likely to the local distribution of alloying elements and their strain fields.

scholarly journals The Dehydrogenation Mechanism and Reversibility of LiBH4 Doped by Active Al Derived from AlH3

Metals ◽  
2019 ◽  
Vol 9 (5) ◽  
pp. 559 ◽  
Author(s):  
Qing He ◽  
Dongdong Zhu ◽  
Xiaocheng Wu ◽  
Duo Dong ◽  
Xiaoying Jiang ◽  
...  
Keyword(s):  
Reaction Products ◽  
X Ray Diffraction ◽  
Scanning Electronic Microscopy ◽  
Electronic Microscopy ◽  
Scanning Calorimetry ◽  
Mass Spectral Analysis ◽  
X Ray ◽  
Mass Spectral ◽  
Al Composite ◽  
Dehydrogenation Mechanism

A detailed analysis of the dehydrogenation mechanism and reversibility of LiBH4 doped by as-derived Al (denoted Al*) from AlH3 was performed by thermogravimetry (TG), differential scanning calorimetry (DSC), mass spectral analysis (MS), powder X-ray diffraction (XRD), scanning electronic microscopy (SEM), and Fourier transform infrared spectroscopy (FTIR). The results show that the dehydrogenation of LiBH4/Al* is a five-step reaction: (1) LiBH4 + Al → LiH + AlB2 + “Li-Al-B-H” + B2H6 + H2; (2) the decomposition of “Li-Al-B-H” compounds liberating H2; (3) 2LiBH4 + Al → 2LiH + AlB2 + 3H2; (4) LiBH4 → LiH + B + 3/2H2; and (5) LiH + Al → LiAl + 1/2H2. Furthermore, the reversibility of the LiBH4/Al* composite is based on the following reaction: LiH + LiAl + AlB2 + 7/2H2 ↔ 2LiBH4 + 2Al. The extent of the dehydrogenation reaction between LiBH4 and Al* greatly depends on the precipitation and growth of reaction products (LiH, AlB2, and LiAl) on the surface of Al*. A passivation shell formed by these products on the Al* is the kinetic barrier to the dehydrogenation of the LiBH4/Al* composite.

Study of the Synthesis of Mullite From Kaolin-α-Al2O3 and Kaolin-Al(NO3)3

2012 ◽  
Vol 1481 ◽  
pp. 11-17
Author(s):  
E. M. Lozada ◽  
O. Alanís ◽  
F. Legorreta ◽  
L. E. Hernández
Keyword(s):  
Combustion Method ◽  
Particle Size Analysis ◽  
Size Analysis ◽  
X Ray Diffraction ◽  
Scanning Electronic Microscopy ◽  
Electronic Microscopy ◽  
X Ray ◽  
Crystallographic Study ◽  
Incomplete Reaction ◽  
Α Al2o3

ABSTRACTThe synthesis of mullite from kaolin clay and two precursors of aluminum: α-Al2O3 and Al(NO3)3 was investigated. In order to study the temperature effect, the system kaolin-α-Al2O3 was calcined in air in a range of 1200 to 1500°C, for 2 h. For the system kaolin-Al(NO3)3, the combustion method was employed, using urea as fuel, and calcined in air at 1500°C for 2 h. The products were characterized by X-ray diffraction, scanning electronic microscopy (SEM), energy dispersive spectroscopy and particle size analysis in order to analyze and compare their morphology and structure. The crystallographic study revealed an incomplete reaction between the kaolin and the α-Al2O3. Nevertheless, in the system kaolin-Al(NO3)3, it was obtained mullite with high purity and trace amounts of cristobalite.

Study on Improving Stainless Steel Antibacterial Capability

2006 ◽  
Vol 510-511 ◽  
pp. 894-897
Author(s):  
Wei Hu Yang ◽  
Yu Bao Li ◽  
Lan Wu ◽  
Ai Ping Yang ◽  
Ji Dong Li ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Chemical Bond ◽  
Steel Surface ◽  
New Method ◽  
Scanning Electronic Microscopy ◽  
Electronic Microscopy ◽  
X Ray ◽  
Naoh Treatment

A new method was studied for improving stainless steel antibacterial capability. The Na2FeO4 coating was prepared on steel surface throughout NaOH treatment, then steel samples were immersed into the solution coantaining Ag+, Zn2+ and TiO2. The antibacterial-ions were fixated firmly on the stainless steel with chemical bond. Scanning electronic microscopy(SEM), X-ray(XRD) and atomic absoption spectroscopy(AAS) were employed to analyze the materials, and the results showed that the antibacterial membrane included silver citrate and silver peroxide. Quinn test was also carried out, in which Staphylococus and E.coli. the results showed that the steel has a bacteriostasis rate of 99.48% to Staphylococus, and 99.09% to E.coli.

Fabrication and Magnetic Properties of Fe3O4 Nanobranches via a Simple Solvothermal Method

2011 ◽  
Vol 335-336 ◽  
pp. 934-939
Author(s):  
Z. F. Zi ◽  
Y. N. Liu ◽  
Q.C. Liu ◽  
Jian Ming Dai ◽  
Yu Ping Sun
Keyword(s):  
Magnetic Properties ◽  
Single Phase ◽  
Solvothermal Method ◽  
X Ray Diffraction ◽  
Scanning Electronic Microscopy ◽  
Electronic Microscopy ◽  
X Ray ◽  
Water Solvent ◽  
Phase Spinel ◽  
Antisite Defects

Magnetite (Fe3O4) nanobranches were synthesized using an improved solvothermal technique in mixed ethanol and water solvent. Structural and magnetic properties were systematically investigated. X-ray diffraction results showed that the sample was single-phase spinel structure. The results of scanning electronic microscopy exhibited that the grains were regular like-branch with sizes from 3 to 6 μm in length and in diameter between 50 and 200 nm. The composition determined by energy dispersive spectroscopy was very close to the stoichiometry of Fe3O4. The saturation magnetizations (Ms) at 10 and 300 K of the synthesized Fe3O4nanobranches were much lower than the theoretical values. On one hand, it could be explained by obstructive magnetizing along their non-easy magnetic axes by the shape anisotropy of Fe3O4nanobranches, on the other hand, lesserMscan also be understood by the existence of antisite defects.

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