Preparation and Study on the Properties of Gypsum Whiskers Reinforced Resin Matrix Composites

2013 ◽  
Vol 327 ◽  
pp. 189-192
Author(s):  
Chuan Wei Du ◽  
Guo Zhong Li
Keyword(s):  
Electron Microscopy ◽  
Cross Section ◽  
Strengthening Mechanism ◽  
Resin Matrix ◽  
Matrix Composites ◽  
X Ray Diffraction ◽  
X Ray ◽  
Resin Matrix Composite ◽  
The Stability ◽  
Scanning Electron

In this paper, gypsum whiskers reinforced resin matrix composites were prepared with the desulfurization gypsum by the technology of atmospheric acidification. The influences of stabilization reagent on the stability of the gypsum whiskers were studied. Meanwhile, the enhanced effects of surface treatment and different contents of gypsum whiskers on the resin matrix composite were analyzed. Scanning electron microscopy, metallographic microscopy, X-ray diffraction test were taken to conduct analysis of the morphology and the aspect ratio of gypsum whiskers. Besides, the mechanical properties of gypsum whiskers reinforced resin matrix composites were tested, and cross-section scanning was used to analyze the strengthening mechanism.

scholarly journals Chemical Stability of Ti3C2 MXene with Al in the Temperature Range 500–700 °C

Materials ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 1979 ◽  
Author(s):  
Jing Zhang ◽  
Shibo Li ◽  
Shujun Hu ◽  
Yang Zhou
Keyword(s):  
Electron Microscopy ◽  
Chemical Stability ◽  
Metal Matrix ◽  
Matrix Composites ◽  
X Ray Diffraction ◽  
X Ray ◽  
Temperature Range ◽  
Transmission Electron ◽  
Work First ◽  
Scanning Electron

Ti3C2Tx MXene, a new 2D nanosheet material, is expected to be an attractive reinforcement of metal matrix composites because its surfaces are terminated with Ti and/or functional groups of –OH, –O, and –F which improve its wettability with metals. Thus, new Ti3C2Tx/Al composites with strong interfaces and novel properties are desired. To prepare such composites, the chemical stability of Ti3C2Tx with Al at high temperatures should be investigated. This work first reports on the chemical stability of Ti3C2Tx MXene with Al in the temperature range 500–700 °C. Ti3C2Tx is thermally stable with Al at temperatures below 700 °C, but it reacts with Al to form Al3Ti and TiC at temperatures above 700 °C. The chemical stability and microstructure of the Ti3C2Tx/Al samples were investigated by differential scanning calorimeter, X-ray diffraction analysis, scanning electron microscopy, and transmission electron microscopy.

scholarly journals The Influence of the Preparation and Stability of Nanofluids for Heat Transfer

2019 ◽  
Vol 25 (4) ◽  
pp. 45-54 ◽  
Author(s):  
Noor Sabih Majeed ◽  
Basma A. Abdulmajeed ◽  
Anwar Khudhur Yaseen
Keyword(s):  
Heat Transfer ◽  
Electron Microscopy ◽  
Base Fluid ◽  
X Ray Diffraction ◽  
Step Method ◽  
X Ray ◽  
Force Microscopy ◽  
Atomic Force ◽  
The Stability ◽  
Scanning Electron

Recently the use of nanofluids represents very important materials. They are used in different branches like medicine, engineering, power, heat transfer, etc. The stability of nanofluids is an important factor to improve the performance of nanofluids with good results. In this research two types of nanoparticles, TiO2 (titanium oxide) and γ-Al2O3 (gamma aluminum oxide) were used with base fluid water. Two-step method were used to prepare the nanofluids. One concentration 0.003 vol. %, the nanoparticles were examined. Scanning Electron Microscopy (SEM), Atomic Force Microscopy (AFM) and X-ray diffraction (XRD) were used to accomplish these tests. The stability of the two types of nanofluids is measured by zeta potential and UV-vis spectrophotometer. The results showed that γ-Al2O3/water has more stable than TiO2/ water for the same period of time.  

scholarly journals Development of TiB and nanocrystalline Ti-reinforced novel hybrid Ti nanocomposite produced by powder metallurgy

2022 ◽  
Author(s):  
D. A. Angel ◽  
T. Mikó ◽  
F. Kristály ◽  
M. Benke ◽  
Z. Gácsi
Keyword(s):  
Electron Microscopy ◽  
Powder Metallurgy ◽  
Hybrid Composites ◽  
Matrix Composites ◽  
X Ray Diffraction ◽  
Transformation Mechanism ◽  
Vacuum Sintering ◽  
X Ray ◽  
Titanium Monoboride ◽  
Scanning Electron

AbstractTitanium monoboride (TiB) whisker-reinforced titanium (Ti) matrix composites were produced by powder metallurgy, through vacuum sintering. TiB is formed by thermal decomposition of TiB2 precursor. In addition, a new hybrid composite was developed by admixing nanograined and nanocrystalline (more important) Ti to enhance the transformation mechanism of TiB2 to TiB phase. The morphology and particle size of the initial powders, mixtures and the microstructure of the composites have been studied by scanning electron microscopy (SEM). The phase analysis and transformation monitoring were performed by X-ray diffraction (XRD). The sintered composites were also subjected to compressive strength and hardness measurements. According to XRD results, through the addition of nanocrystalline Ti, a probable enhancement of the TiB2 → TiB transformation occurred producing more TiB whiskers in the hybrid composites. All samples of the hybrid composites exhibited improved yield strength (1365 MPa) and hardness (358 HV) compared to the non-hybrid ones 927 MPa and 254 HV, respectively. Graphical abstract

Microstructure Evolution of In Situ Synthesized VC Reinforced Iron Matrix Composites

2012 ◽  
Vol 217-219 ◽  
pp. 71-74
Author(s):  
Jing Wang ◽  
Si Jing Fu ◽  
Shu Yong Jiang ◽  
Hong Cheng
Keyword(s):  
Electron Microscopy ◽  
In Situ Synthesis ◽  
Matrix Composites ◽  
X Ray Diffraction ◽  
Iron Matrix ◽  
X Ray ◽  
Matrix Microstructure ◽  
The Matrix ◽  
Scanning Electron

Iron matrix composite reinforced with VC reinforcements was produced by in situ synthesis technique. The microstructure of the composites was characterized by X-ray diffraction and scanning electron microscopy. The micrographs revealed the morphology and distribution of the reinforcements. The results show that the composite consists of VC carbide as the reinforcing phase and α-Fe as the matrix. The distribution of spherical VC particulates in iron matrix is uniform, and the matrix microstructure of Fe-VC composite is pearlite.

Low Temperature Oxidation Behaviors of CNTs/MoSi2 Composites

2014 ◽  
Vol 983 ◽  
pp. 116-120
Author(s):  
Houan Zhang ◽  
He Jian Wu ◽  
Jia Lin ◽  
Si Yong Gu ◽  
Lei Yu
Keyword(s):  
Electron Microscopy ◽  
Molybdenum Disilicide ◽  
Phase Identification ◽  
Matrix Composites ◽  
X Ray Diffraction ◽  
Low Temperature Oxidation ◽  
Temperature Oxidation ◽  
X Ray ◽  
Scanning Electron ◽  
Oxidation Behaviors

Molybdenum disilicide (MoSi2) matrix composites with various contents of carbon nanotubes (CNTs) were fabricated by sintering in vacuum at 1550 °C for 1 h. The oxidation behaviors of CNTs/MoSi2composites at 400 °C and 500 °C for 200 h in air were studied. Results showed that the weight loss of CNTs/MoSi2composites increased with the increase of CNTs content. “Pest” phenomenon happened at 400 °C but not at 500 °C. Phase identification and microstructure of the samples were analyzed by X-ray diffraction (XRD) and scanning electron microscopy (SEM). It was found that many MoO3whiskers and microcracks only occurred on the surface of CNTs/MoSi2composites when oxidized at 400 °C in air, which leaded to the catastrophic disintegration of CNTs/MoSi2composites.

Ta-Si-N and Si3N4 Encapsulants for InP

1992 ◽  
Vol 260 ◽  
Author(s):  
J. S. Reid ◽  
R. P. Ruiz ◽  
E. Kolawa ◽  
J. S. Chen ◽  
J. Madok ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Thin Films ◽  
Scanning Electron Microscopy ◽  
X Ray Diffraction ◽  
X Ray ◽  
Face To Face ◽  
Metallic Conductor ◽  
The Stability ◽  
Inp Substrates ◽  
Scanning Electron

ABSTRACTThin films of sputtered, amorphous Ta36Si14N50 (a metallic conductor) and Si3N4 (an insulator) were evaluated as encapsulants for (100)-oriented InP substrates. Thicknesses of both films were approximately 100 nm. During a 15 min annealing in Ar, liberated phosphorus was gettered by a <Si>ISiO2ITa(100 nm) collector placed face-to-face on encapsulated or non-encapsulated InP. The stability of the InP with the encapsulant was characterized by backscattering spectrometry, scanning electron microscopy, and x-ray diffraction. As measured by 4He++ backscattering spectrometry, detectable amounts of phosphorus do not arise in the Ta collectors for the Ta-Si-N and Si3N4 encapsulation schemes until 650 and 700°C, respectively. Failure of the Ta36Si14N50 film is catastrophic at 700°C whereas the Si3N4 film degrades locally commencing at 600°C.

On the Stability of YBa2Cu3O7-y with Refractory Ceramics

1989 ◽  
Vol 169 ◽  
Author(s):  
P. Del Angel ◽  
J. M. Dominguez ◽  
C. Falcony ◽  
O. Guzman ◽  
A. Montoya ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Electrical Resistance ◽  
Partial Substitution ◽  
X Ray Diffraction ◽  
Electrical Measurements ◽  
Ceramic Oxides ◽  
X Ray ◽  
The Stability ◽  
Refractory Ceramics ◽  
Scanning Electron

AbstractA series of ceramic oxides were prepared by adding alumina to the superconductor YBaCuO. The solids were characterized by X-ray diffraction, transmission (TEM) and scanning electron microscopy (SEM) with EDS and electrical measurements. Partial drops in electrical resistance (R ≠ 0) indicate the presence of superconducting phases trapped in ceramic masses. Additionally, the systematic diminution of Tc could indicate a partial substitution of Cu by Al.

Selective Laser Sintering of Different Powders of Co-Cr-Mo

2014 ◽  
Vol 802 ◽  
pp. 338-342
Author(s):  
Claudinei dos Santos ◽  
Paula Cipriano da Silva ◽  
Luciane Carvalho de Paula ◽  
Alexandre Fernandes Habibe ◽  
Jefferson Fabrício C. Lins ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Particle Size ◽  
Size Distribution ◽  
Cross Section ◽  
Selective Laser Sintering ◽  
Laser Sintering ◽  
X Ray Diffraction ◽  
X Ray ◽  
Scanning Electron

In this work, different commercial Co-Cr-Mo powders were used in selective laser sintering. Commercial powders with particle size distribution between 5 and 50μm were sintered by laser sintering, and characterized. The samples were characterized by X-ray diffraction, indicating Co as the only crystalline phase. Relative density was measured by Archimedes method showing values between 90 and 96% of TD, depending on the powder used. Scanning electron microscopy performed on the cross section of the sintered samples, indicates that the microstructural features are similar, but the surface finish of the samples differ significantly due to the morphology and size distribution of the starting powders used.

scholarly journals Nanostructure of Crystal Hydroxyapatite from Fluorosis: Affected Enamel

2011 ◽  
Vol 2 (4) ◽  
pp. 321-325
Author(s):  
Abdillah Imron Nasution
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Grain Size ◽  
Surface Structure ◽  
X Ray Diffraction ◽  
X Ray ◽  
The Stability ◽  
Scanning Electron

ABSTRACT Fluorosis is a condition due to ingestion of excessive amounts of fluor which can cause the change the teeth structure and strength. Currently, a little explanation was available to describe the surface and change of nanostructure crystal hydroxyapatite which contribute to influence the macrocharacteristic of fluorosis enamel. Aims and objectives To describe the change of surface structure, c-axis, a-axis and grain size of crystal hydroxyapatite on fluorosis enamel. Materials and methods This research was carried out the fluorosis and normal enamel specimen by using scanning electron microscopy/ energy disperse X-ray (SEM/EDX) to determine fluor concentration and the surfaces structure of fluorosis enamel, and powder X-ray diffraction (XRD) to determine change of c- and a-axis of hydroxyapatite of fluorosis enamel. Results Fluor concentration were higher in fluorosis enamel and the surface increasingly roughness and porous. SEM/EDX also confirmed gaps areas between enamel rods and visible aprismatic zone in some regions. The axis on fluorosis enamel was a-axis = 9.3786 Å and c-axis = 6.8836 Å. The a-axis on normal enamel was = 9.4148 Å and c-axis = 6.8791 Å. Grain size of fluorosis enamel was 19.59 nm and normal enamel was 20.30 nm. Conclusion Fluor as most electronegative element changes the c-axis, a-axis, and grain size of crystal hydroxyapatite and generates the internal atomic bonding which influences the stability of enamel strength.

Freeze-Fracture Replication of Frozen Outer Segments of Rat Retinal Rods

1969 ◽  
Vol 27 ◽  
pp. 392-393
Author(s):  
Thomas S. Leeson ◽  
C. Roland Leeson
Keyword(s):  
Electron Microscopy ◽  
Cross Section ◽  
Outer Segment ◽  
Freeze Fracture ◽  
X Ray Diffraction ◽  
X Ray ◽  
Outer Segments ◽  
Retinal Rods ◽  
Temperature Electron ◽  
Freeze Etching

Numerous previous studies of outer segments of retinal receptors have demonstrated a complex internal structure of a series of transversely orientated membranous lamellae, discs, or saccules. In cones, these lamellae probably are invaginations of the covering plasma membrane. In rods, however, they appear to be isolated and separate discs although some authors report interconnections and some continuities with the surface near the base of the outer segment, i.e. toward the inner segment. In some species, variations have been reported, such as longitudinally orientated lamellae and lamellar whorls. In cross section, the discs or saccules show one or more incisures. The saccules probably contain photolabile pigment, with resulting potentials after dipole formation during bleaching of pigment. Continuity between the lamina of rod saccules and extracellular space may be necessary for the detection of dipoles, although such continuity usually is not found by electron microscopy. Particles on the membranes have been found by low angle X-ray diffraction, by low temperature electron microscopy and by freeze-etching techniques.

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