Preparation Process Optimization and Characterization of an Ultra-Hard Al-Mg-B Material

2009 ◽  
Vol 79-82 ◽  
pp. 279-282
Author(s):  
Gang Feng ◽  
Lin Zhang ◽  
Guang Hui Min
Keyword(s):  
Bending Strength ◽  
Raw Materials ◽  
Weight Ratio ◽  
Sintered Body ◽  
X Ray Diffraction ◽  
X Ray ◽  
Sinter Method ◽  
The Matrix ◽  
Metal Borides

The Al-Mg-B polycrystalline bodies were prepared using vacuum hot-pressing sinter method by pure Al, Mg and B powders. Process parameters and constitution variation were investigated to obtain compact Al-Mg-B sintered body with high mechanical properties. Al-13%Mg-72.7%B(weight ratio) sintered body prepared under 1600°C, 30MPa for 1 hour in vacuum was proved to be optimum, which bending strength was 156MPa and Vickers hardness was 2220. X-ray diffraction (XRD), Micron Probe Micro-analyzer (EPMA) were employed to analyse the ultimate phases. The results showed that the matrix phases were metal borides including AlB12, MgB6 and AlMgB14, while Al2O3 and MgAl2O4 phases existed which connected or filled in the matrix grains to promote the compactness degree, where oxygen introduced from impurities in raw materials. A portion of Mg in AlMgB14 combined with oxygen during heating to 1600°C which helped to form MgAl2O4 and AlB12 in the end.

Structure Characterization of Sintered CaO-Al2O3-SiO2 Glass-Ceramic Reinforced with Spodumene

2013 ◽  
Vol 834-836 ◽  
pp. 309-314
Author(s):  
Zi Fan Xiao ◽  
Jin Shu Cheng ◽  
Jun Xie
Keyword(s):  
Glass Ceramic ◽  
Energy Dispersive Spectrometry ◽  
Crystal Size ◽  
Bending Strength ◽  
Glass Ceramics ◽  
Structure Characterization ◽  
X Ray Diffraction ◽  
Crystalline Phases ◽  
X Ray

A glass-ceramic belonging to the CaO-Al2O3-SiO2(CAS) system with different composition of spodumene and doping the Li2O with amount between 0~2.5 % (mass fraction) were prepared by onestage heat treatment, under sintering and crystallization temperature at 1120 °C for two hours. In this paper, differential thermal analysis, X-ray diffraction, scanning electron microscopy, energy dispersive spectrometry and bending strength test were employed to investigate the microstructure and properties of all samples. β-wollastonite crystals were identified as the major crystalline phases, and increasing Li2O was found to be benefit for the crystallization and tiny crystalline phases remelting, resulting in the content of major crystalline phases increased first and then decreased with increasing the expense of spodumene. Meanwhile, the crystal size can be positively related with the content of Li2O. The preferable admixed dosage of spodumene can be obtained, besides the strength of glass-ceramics can be more than 90 MPa.

Characterization of Electrospun Poly(Lactic Acid)/polyaniline Blend Nanofibers

2011 ◽  
Vol 332-334 ◽  
pp. 317-320 ◽  
Author(s):  
Hui Qin Zhang
Keyword(s):  
Lactic Acid ◽  
Composite Nanofibers ◽  
Weight Ratio ◽  
Electrospinning Process ◽  
Poly Lactic Acid ◽  
X Ray Diffraction ◽  
Sem Images ◽  
X Ray ◽  
Ft Ir

In this study, composite nanofibers of polyaniline doped with dodecylbenzene sulfonic acid (PANI-DBSA) and Poly(lactic acid) (PLA) were prepared via an electrospinning process. The surface morphology, thermal properties and crystal structure of PLA/PANI-DBSA nanofibers are characterized using Fourier transform infrared spectroscopy (FT-IR), wide-angle x-ray diffraction (WAXD) and scanning electron microscopy (SEM). SEM images showed that the morphology and diameter of the nanofibers were affected by the weight ratio of blend solution.

Preparation and characterization of poly(3-glycidoxypropyltrimethoxysilane) nanocomposite using organophilic montmorillonite clay (Mag-cetyltrimethylammonium)

2019 ◽  
Vol 53 (28-30) ◽  
pp. 4313-4322 ◽  
Author(s):  
Nadia Embarek ◽  
Nabahat Sahli ◽  
Mohammed Belbachir
Keyword(s):  
Thermal Properties ◽  
Preparation Method ◽  
X Ray Diffraction ◽  
Scanning Electronic Microscopy ◽  
X Ray ◽  
The Matrix ◽  
Organophilic Clay ◽  
Linear Poly ◽  
Organophilic Montmorillonite

Nanocomposites of linear poly(3-glycidoxypropyltrimethoxysilane) based on Algerian natural organophilic clay: montmorillonite–cetyltrimethylammonium named Maghnite-CTA were prepared by enhancing the dispersion of the matrix polymer in sheets of the organoclay. The effect of the organoclay, used with different amounts (3, 5, and 7% by weight) and the preparation method were studied in order to determine and evaluate their structural, morphological and thermal properties. X-ray diffraction analysis of obtained nanocomposites showed a significant change in the distance interlayer of montmorillonite–cetyltrimethylammonium. Therefore, interlayer expansion and exfoliation of linear poly(3-glycidoxypropyltrimethoxysilane) between layers of montmorillonite–cetyltrimethylammonium were observed. The thermal properties of the prepared nanocomposites were given by thermogravimetric analysis. The structure and morphology of the obtained materials were determined respectively by Fourier transform infrared spectroscopy and scanning electronic microscopy. The results obtained have approved the privilege of the intercalation of linear poly(3-glycidoxypropyltrimethoxysilane) in the interface of montmorillonite–cetyltrimethylammonium and the best quantity of organoclay required to prepare nanocomposite with a high thermal stability is 5% (by weight).

scholarly journals Characterization of FeOOH Nanoparticles and Amorphous Silica Matrix in an FeOOH-SiO2Nanocomposite

2008 ◽  
Vol 2008 ◽  
pp. 1-6 ◽  
Author(s):  
Guido Ennas ◽  
Maria F. Casula ◽  
Sergio Marras ◽  
Gabriele Navarra ◽  
Alessandra Scano ◽  
...  
Keyword(s):  
Hydrochloric Acid ◽  
Amorphous Silica ◽  
Diffraction Data ◽  
Silica Matrix ◽  
X Ray Diffraction ◽  
X Ray ◽  
The Matrix ◽  
Curve Method ◽  
Hydrolysis Of

A nanocomposite with an FeOOH/SiO2ratio equal to 17.7 wt% and the pertinent matrix, obtained by etching away the nanoparticles through reaction with hydrochloric acid, were investigated by XRD, TGA-DTA, heliostereopicnometry, BET, and TEM techniques. The study shows the presence in the nanocomposite of ferrihydrite nanoparticles phase with average dimensions around 4 nm. The FeOOH nanoparticles structure was analyzed by synchrotron X-ray diffraction data using the distribution difference curve method. The porous structure of the matrix resulting by etching away the nanoparticles differs significantly from that of a pureSiO2sample obtained by hydrolysis of TEOS under the same operative conditions followed in the nanocomposite preparation.

Synthesis and Characterization of New Polyurethane Adhesives

2006 ◽  
Vol 514-516 ◽  
pp. 843-847 ◽  
Author(s):  
Cristina Borges Correia ◽  
João C. Bordado
Keyword(s):  
Raw Materials ◽  
Impact Resistance ◽  
Inert Atmosphere ◽  
Stray Field ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Polyurethane Adhesives ◽  
Dimer Acids

Polyurethane adhesives provide excellent flexibility, impact resistance and durability. Polyurethanes are formed through the reaction of an isocyanate component with polyether or polyester polyols or other active hydrogen compounds. This paper refers to polyurethane adhesives made from polyester polyols with long aliphatic chains (up to 36 carbon atoms) and MDI (diphenylmethane-4,4’-diisocyanate). The polyester polyols have been made from dimer acids obtained from renewable sources and short chain diols. The polyols that were used presented different degrees of unsaturation. The influence of the different raw materials in the adhesives performance is studied. The polyurethanes were produced by reaction between quasi-stoichiometric quantities of polyol and MDI, at several temperatures. The reaction was carried under inert atmosphere and at temperatures below 100°C. Performance of the adhesives was tested by carrying adhesion, hardness and water absorption tests. Characterization of both the polyester polyols and polyurethane adhesives was carried by Fourier Transform Infrared Spectroscopy (FTIR), Differential Scanning Calorimetry (DSC), Magnetic Nuclear Resonance (NMR), X-Ray Diffraction (WAXD), Scanning RMN Imaging of 1H of Stray- Field b (MRI) and Brookfield viscometry.

Fabrication and Characterization of a Feldspar-Alumina for Dental Ceramic

2010 ◽  
Vol 160-162 ◽  
pp. 424-427
Author(s):  
Guang Lei Zhang ◽  
Guo Qiang Qin ◽  
Yuan Hua Zhang ◽  
Pu Cheng ◽  
Chang Tao Shao
Keyword(s):  
Sinter Temperature ◽  
Bending Strength ◽  
Dental Ceramics ◽  
Alumina Ceramics ◽  
X Ray Diffraction ◽  
X Ray ◽  
Fabrication And Characterization ◽  
Sintering Method ◽  
Scanning Electron

Feldspar-alumina dental ceramics were produced by impressed sintering method and characterized by X-ray diffraction and scanning electron microscope techniques. The machinability of the obtained alumina ceramics was evaluated by grinding capacity in the simulative grinding experiment. The results show that an appropriate amount of feldspar additive can reduce the sinter temperature and improve density, bending strength and machinability of alumina dental ceramics. Under 10 wt% feldspar and 1450 °C sinter temperature, the relative density and bending strength of ceramic reached 93.62% and 235MPa, respectively.

Development and Characterization of Cementing Composites with Blast Furnace Slag Replacement

2014 ◽  
Vol 976 ◽  
pp. 246-250
Author(s):  
Reyna Sánchez-Ramírez ◽  
Manuela Diaz-Cruz ◽  
Sebastían Díaz de La Torre ◽  
Enrique Rocha-Rangel
Keyword(s):  
Blast Furnace ◽  
Blast Furnace Slag ◽  
Bending Strength ◽  
Isothermal Calorimetry ◽  
Oil Wells ◽  
X Ray Diffraction ◽  
Hydration Kinetics ◽  
X Ray ◽  
Furnace Slag

In this work, they were produced and characterized cementing composites made with blast furnace slag replacement, for their use in the construction of oil wells. To this, slurries were prepared with a replacement of 20 and 30% slag, as well as a slurry with 100 % slag and a slurry with 100% H-cement were prepared. Starting materials were characterized by chemical analysis, X-ray diffraction and Fourier Transformed Infra Red. Slurries also were activated with sodium silicate in order to study theirs hydration kinetics, driving by isothermal calorimetry. These studies were complemented by the preparation of specimens of 4 X 4 X 16 cm to which they determine its compressive and bending strength during 2 and 28 days of curing. From the results it can be concluded that it was obtained a product that can be effectively used in the construction of oil wells.

scholarly journals Microstructural evolution of a modified HP alloy: experimental and complementary computational study

2017 ◽  
pp. 5141-5145
Author(s):  
Sandra Simonetti ◽  
C. Lanz ◽  
G. Brizuela ◽  
A. Juan
Keyword(s):  
Computational Study ◽  
Microstructural Characterization ◽  
X Ray Diffraction ◽  
X Ray ◽  
Eutectic Carbides ◽  
The Matrix ◽  
Secondary Precipitates ◽  
M23c6 Carbides ◽  
Cast Condition

In this work is presented results of the microstructural characterization of austenitic stainless steel (HP series) modified with Nb, aged at temperatures of 750, 800, 850, 900 and 950oC in air at different times. Microstructural changes were analyzed using optical microscopy, scanning electron microscopy (SEM) equipped with (EDS), x-ray diffraction and Vickers hardness. In the as-cast condition, the microstructure consists of an austenitic matrix and eutectic carbides network, Cr, Nb-rich carbides. The Cr-rich carbides are M7C3 type, whereas, those rich in Nb are NbC. During aging, there is a second precipitation in the matrix of very fine needle form of M23C6 carbides, which leads to an increase in hardness. After that, the decreasing in hardness is associated with a coalescence phenomenon of the secondary precipitates. Computational modeling shows that M23C6 is lesser stable than M7C3 carbide.

Characterization of Ni75Mo25 Alloy Prepared by Mechanical Alloying and Heat Treatment

2013 ◽  
Vol 203-204 ◽  
pp. 394-397
Author(s):  
Joanna Panek ◽  
Bożena Bierska-Piech ◽  
Jolanta Niedbała
Keyword(s):  
Heat Treatment ◽  
Mechanical Alloying ◽  
Weight Ratio ◽  
Milling Process ◽  
Particle Sizes ◽  
X Ray Diffraction ◽  
Powder Synthesis ◽  
X Ray ◽  
Microscopy Techniques

The process of Ni75Mo25powder synthesis via mechanical alloying (MA) was studied. Process was carried out from pure elements: Ni and Mo with a particle size under 150 μm. A ball-to-powder weight ratio and the rotational speed were 5:1 and 500 rpm, respectively. Oxidation was reduced by milling under an argon atmosphere. The milling process was performed during up to 60 hours. X-ray diffraction (XRD) and scanning electron microscopy techniques have been used to investigate resulting products. It was found that the particle sizes decrease with the increase in milling time. The resulting powder consists of metastable Ni(Mo) and Mo(Ni) solid solutions. Milled Ni75Mo25 powder was subjected to heat treatment at temperature of 773K, 973K and 1173K. As a result of annealing the formation of Ni4Mo and NiMo intermetallic phases was observed.

Characterization of Portuguese gypsums as raw materials for dermocosmetics

Clay Minerals ◽  
2019 ◽  
Vol 54 (3) ◽  
pp. 277-281 ◽  
Author(s):  
Cristiana Costa ◽  
António Fortes ◽  
Fernando Rocha ◽  
Angela Cerqueira ◽  
Delfim Santos ◽  
...  
Keyword(s):  
Calcium Sulfate ◽  
Raw Materials ◽  
Cement Industry ◽  
Oil Absorption ◽  
Chemical Quality ◽  
X Ray Diffraction ◽  
X Ray ◽  
White Cement ◽  
Wet Sieving

AbstractPortuguese gypsum deposits utilized by the cement industry were characterized mineralogically, chemically and technologically for possible application in dermocosmetics. The deposits studied (Loulé, Óbidos and Soure) correspond to small outcrops in diapiric anticline areas. In principle, they represent gypsites which are white, and generally of higher quality for traditional applications (e.g. white cement), or greyish, and generally not adequate for cements and mortars. The analytical methods used to characterize the materials were wet sieving and X-ray sedimentation, X-ray diffraction, X-ray fluorescence spectrometry and assessment of abrasiveness, plasticity, texturometrics (adhesivity and firmness), oil absorption and cooling rate. The Óbidos gypsum displayed greater mineralogical and chemical quality (almost pure calcium sulfate) and had a finer grain size (<63 μm), whereas Loulé and Soure gypsums contain mineralogical impurities (mainly quartz). The Óbidos gypsum shows good characteristics in general for application in dermocosmetics because of its absorption, plasticity, adhesivity, firmness and low abrasiveness.

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