Microstructures and Properties of Fe/B-Fe Coating Used in Circulating Fluidized Bed Boiler

2011 ◽  
Vol 66-68 ◽  
pp. 1528-1532
Author(s):  
Qi Fa Tian ◽  
Hong Fei Sun
Keyword(s):  
Electron Probe ◽  
Circulating Fluidized Bed ◽  
Steel Substrate ◽  
Electric Arc ◽  
Bare Metal ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Mechanical Performances ◽  
Electronic Microscope

Electric arc praying technology was used to produce Fe/B-Fe coating on the carbon steel substrate. The microstructures was studied by means of scanning electronic microscope (SEM), X-ray diffraction (XRD), transmission electron microscope (TEM) and electron probe microanalysis (EPMA). Mechanical performances, wear resistance of coating were tested . The results showed that the resistance to abrasion and corrosion of Fe/B-Fe coating was respectively 16 times and 5 to 6 times higher than those of bare metal.

Estimation of Interdiffusivities of the Pseudo NiAl Binary Phase Formed in a Nickel-based Superalloy by Pack Cementation

2005 ◽  
Vol 20 (9) ◽  
pp. 2340-2347 ◽  
Author(s):  
H. Wei ◽  
X.F. Sun ◽  
Q. Zheng ◽  
H.R. Guan ◽  
Z.Q. Hu ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Electron Probe ◽  
Pack Cementation ◽  
X Ray Diffraction ◽  
X Ray ◽  
Binary Phase ◽  
Nickel Based Superalloy ◽  
Transmission Electron ◽  
Scanning Electron

The pseudo NiAl binary phase was formed in a nickel-based superalloy by pack cementation. Scanning electron microscopy, transmission electron microscopy, x-ray diffraction, electron probe microanalysis, and positron annihilation technique were used to characterize the pseudo NiAl binary phase. Based on reasonable assumptions, the chemical interdiffusivities of the pseudo NiAl binary phase were then assessed by means of the modified Wagner’s method. The results showed that the chemical interdiffusivities of the pseudo NiAl binary phase were about two orders of magnitude lower than those reported by others. The analysis indicated that the change in thermodynamic properties due to the additions of the microalloying atoms originally present in a superalloy could be responsible mainly for a decrease in chemical interdiffusivities.

Preparation and Characterization of Ti0.6Cr0.4OxNy Nano-Sized Powder

2008 ◽  
Vol 368-372 ◽  
pp. 1130-1132
Author(s):  
Hong Zhi Wang ◽  
Qi Zhang ◽  
Yun Xin Gu ◽  
Yao Gang Li ◽  
Mei Fang Zhu
Keyword(s):  
Surface Area ◽  
Electron Probe ◽  
Auger Electron ◽  
Bet Surface Area ◽  
X Ray Diffraction ◽  
X Ray ◽  
Nano Powder ◽  
Transmission Electron ◽  
Cubic Structure

Ti0.6Cr0.4OxNy bimetallic metal oxynitride nano powder was synthesized by ammonolysis of the nanosized Cr2O3/TiO2 composite powder with n(Ti):n(Cr)=6:4 at 800oC for 8 h. The precursor and the resulting oxynitride were characterized by Auger electron spectroscope (AES), X-ray diffraction analysis (XRD), electron probe microanalysis (EPMA), transmission electron microscopy (TEM), and BET surface area techniques. The result indicated that the precursor was homogenous mixture of Cr2O3 and TiO2 with high BET surface area. The as-synthesized oxynitride powder contains only Ti0.6Cr0.4OxNy with cubic structure. The BET surface area of the oxynitride powder is 37.42 m2/g and the particle size is in the range of 20~30 nm.

Microstructure and Hardness Characterization of a NiCr/Cr3C2 Coating by High-Velocity Oxy-Fuel Thermal Spraying

2009 ◽  
Vol 79-82 ◽  
pp. 397-400
Author(s):  
Yu Ping Wu ◽  
Gai Ye Li
Keyword(s):  
Electron Microscopy ◽  
Stainless Steel ◽  
High Velocity ◽  
Steel Substrate ◽  
Thermal Spraying ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Hvof Thermal Spraying

A NiCr/Cr3C2 composite coating with a thickness of approximately 200 m was deposited onto 1Cr18Ni9Ti stainless steel substrate by high-velocity oxy-fuel (HVOF) thermal spraying. Microstructure of the coating was characterized using X-ray diffraction(XRD), scanning electron microscopy(SEM) and transmission electron microscopy (TEM). The coating comprised a NiCr matrix and two types of carbides. The NiCr matrix was composed of an amorphous phase and nanocrystalline grain with a size of 10–50 nm. The microhardness of the coating was found to be 1200Hv, which is significantly greater than that of the stainless steel (1Cr18Ni9Ti) substrate (285 Hv).

Synthesis of Ca Decorated Carbon Nanostructures for Hydrogen Storage

2009 ◽  
Vol 1204 ◽  
Author(s):  
Daniele Mirabile Gattia ◽  
Marco Vittori Antisari ◽  
Renzo Marazzi ◽  
Amelia Montone ◽  
Emanuela Piscopiello ◽  
...  
Keyword(s):  
Carbon Nanostructures ◽  
Alkaline Earth ◽  
Electric Arc ◽  
X Ray Diffraction ◽  
Carbon Nanostructure ◽  
Simple Method ◽  
X Ray ◽  
Carbon Nanohorns ◽  
Transmission Electron ◽  
Single Wall Carbon Nanohorns

AbstractThe AC powered electric arc has been used to synthesize single wall carbon nanohorns aggregates with Ca dispersed inside. To this purpose the electric arc has been ignited between two electrodes, one of which was constituted by a mixture of graphite and CaCO3. The experimental evidence on the microstructure and on the chemical composition has been obtained by observation with a transmission electron microscope equipped with X-ray microanalysis. X-ray diffraction revealed the presence of residual CaCO3 indicating that the process has still to be optimized. The experiment represents a first attempt to decorate carbon nanostructures with alkaline earth metals, in particular Ca, by this relatively simple method. These composites are theorized to adsorb relevant amounts of hydrogen. Further work will be focused to optimize the dispersion of Ca atoms in the carbon nanostructure.

Microstructure of Al2O3-13TiO2 Coatings Deposited from Nanoparticles by Plasma Spraying

2013 ◽  
Vol 58 (2) ◽  
pp. 335-339 ◽  
Author(s):  
A. Góral ◽  
L. Litynska-Dobrzynska ◽  
W. Zórawski ◽  
K. Berent ◽  
J. Wojewoda-Budka
Keyword(s):  
Plasma Spraying ◽  
Steel Substrate ◽  
Nanosized Particles ◽  
X Ray Diffraction ◽  
X Ray ◽  
Lamellar Morphology ◽  
Transmission Electron ◽  
Plasma Sprayed ◽  
Plasma Spraying Process ◽  
Spraying Process

The aim of the study was to characterize nanostructured Al2O3-13TiO2 coatings deposited by plasma spraying on a grit blasted steel substrate. The Al2O3-13TiO2 coatings were characterized using scanning and transmission electron microscopy and X-ray diffraction techniques. Obtained coatings possessed a unique microstructure consisting of fully melted regions with the microstructure similar to a typical plasma sprayed lamellar morphology as the conventional coatings and areas comprising unmelted or partially melted nanosized particles. The analysis showed that most of the α-Al2O3 phase from the nanostructured powders transformed into γ-Al2O3 phase after plasma spraying process. Moreover, the presence of amorphous phase was also observed.

Practical and Fundamental Studies of Nanocrystalline Composite Thin Films

1994 ◽  
Vol 356 ◽  
Author(s):  
Yang-Tse Cheng ◽  
Boqin Qiu ◽  
Simon Tung ◽  
J. P. Blanchard ◽  
G. Drew
Keyword(s):  
Grain Size ◽  
Wear Rate ◽  
Electron Probe ◽  
Friction And Wear ◽  
Composite Films ◽  
X Ray Diffraction ◽  
X Ray ◽  
Practical Applications ◽  
Transmission Electron ◽  
Nanocrystalline Composite

AbstractNanocrytslline composite films of Ag-Mo and Ag-Ni have been made by a co-deposition technique in UHV. The structure and composition have been studied by x-ray diffraction (XRD), transmission electron microscopy (TEM), and electron probe microanalysis (EPMA). For practical applications, the friction coefficient and wear rate were measured using a pin-on-plate machine for Ag-Mo composites deposited on steel. For fundamental studies, the hardness of the Ag-Ni composites deposited on oxidized Si wafers was measured using a nanoindenter. Experiments show that (1) reduction of friction and wear rate can be achieved using these nanocomposite coatings and (2) the hardness of the nanocomposites depends on the grain size. As the grain size of the Ag decreases from 100 to 10 nm, the hardness increases about 4 times.

Synthesis of Si-O-C Nanoballs by CVD of Polydimethylsiloxane

2012 ◽  
Vol 454 ◽  
pp. 114-117
Author(s):  
Xia Yuan ◽  
Yu Liang An ◽  
Hong Chao Sui ◽  
Chen Zhang
Keyword(s):  
Chemical Vapor ◽  
X Ray Diffraction ◽  
X Ray ◽  
Cvd Method ◽  
Silicon Carbon ◽  
Transmission Electron ◽  
Diffraction Patterns ◽  
Two Populations ◽  
Scan Electronic Microscope ◽  
Electronic Microscope

Here we reported that the Si-O-C nanoballs (SCONBs) were yielded from polyorganosiloxane, polydimethylsiloxane, by chemical vapor deposition (CVD) method. The composite nanoballs with a range of diameters from 50 to 200nm were composed of silicon, carbon and oxygen based on analysis of EDX. At the transmission electron microscope(TEM) and scan electronic microscope(SEM), two populations of nanoballs were found: around 200nm and 500nm. X-ray diffraction patterns demonstrated that the nanoballs were dominatingly amorphous. Temperature played an key role in size distribution of Si-O-C nanoballs, and the 850–900°C temperature range was typical for nanoparticles growth via CVD.

The Use of Advanced Analytical Techniques for Characterization of the Chemical, Physical, and Crystallographic Nature of a Surface

1973 ◽  
Vol 31 ◽  
pp. 132-133 ◽  
Author(s):  
R. E. Herfert
Keyword(s):  
Surface Characterization ◽  
Analytical Techniques ◽  
X Ray Diffraction ◽  
Depth Of Penetration ◽  
X Ray ◽  
The Past ◽  
Transmission Electron ◽  
Scanning Electron

Studies of the nature of a surface, either metallic or nonmetallic, in the past, have been limited to the instrumentation available for these measurements. In the past, optical microscopy, replica transmission electron microscopy, electron or X-ray diffraction and optical or X-ray spectroscopy have provided the means of surface characterization. Actually, some of these techniques are not purely surface; the depth of penetration may be a few thousands of an inch. Within the last five years, instrumentation has been made available which now makes it practical for use to study the outer few 100A of layers and characterize it completely from a chemical, physical, and crystallographic standpoint. The scanning electron microscope (SEM) provides a means of viewing the surface of a material in situ to magnifications as high as 250,000X.

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.

Identification of calcium oxalate crystals in dried or fixed tobacco leaf

1984 ◽  
Vol 42 ◽  
pp. 288-289
Author(s):  
Vicki L. Baliga ◽  
Mary Ellen Counts
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Calcium Oxalate ◽  
Growth And Development ◽  
Polarized Light ◽  
Calcium Oxalate Crystals ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Scanning Electron

Calcium is an important element in the growth and development of plants and one form of calcium is calcium oxalate. Calcium oxalate has been found in leaf seed, stem material plant tissue culture, fungi and lichen using one or more of the following methods—polarized light microscopy (PLM), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and x-ray diffraction.Two methods are presented here for qualitatively estimating calcium oxalate in dried or fixed tobacco (Nicotiana) leaf from different stalk positions using PLM. SEM, coupled with energy dispersive x-ray spectrometry (EDS), and powder x-ray diffraction were used to verify that the crystals observed in the dried leaf with PLM were calcium oxalate.

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