scholarly journals Chemical and Structural Analysis of Newly Prepared Co-W-Al Alloy by Aluminothermic Reaction

Materials ◽  
2022 ◽  
Vol 15 (2) ◽  
pp. 658
Author(s):  
Štefan Michna ◽  
Anna Knaislová ◽  
Iryna Hren ◽  
Jan Novotný ◽  
Lenka Michnová ◽  
...  
Keyword(s):  
Phase Composition ◽  
High Temperature ◽  
Structural Analysis ◽  
Surface Coating ◽  
Al Alloy ◽  
Metal Carbides ◽  
Aluminothermic Reaction ◽  
Carbide Particles ◽  
Very High

This article is devoted to the characterization of a new Co-W-Al alloy prepared by an aluminothermic reaction. This alloy is used for the subsequent preparation of a special composite nanopowder and for the surface coating of aluminum, magnesium, or iron alloys. Due to the very high temperature (2000 °C–3000 °C) required for the reaction, thermite was added to the mixture. Pulverized coal was also added in order to obtain the appropriate metal carbides (Co, W, Ti), which increase hardness, resistance to abrasion, and the corrosion of the coating and have good high temperature properties. The phase composition of the alloy prepared by the aluminothermic reaction showed mainly cobalt, tungsten, and aluminum, as well as small amounts of iron, titanium, and calcium. No carbon was identified using this method. The microstructure of this alloy is characterized by a cobalt matrix with smaller regular and irregular carbide particles doped by aluminum.

scholarly journals Characterization of 2D-C/C Composite for Application of Very High Temperature Reactor(M & M 2009 Conference)

2010 ◽  
Vol 76 (764) ◽  
pp. 383-385 ◽  
Author(s):  
Taiju SHIBATA ◽  
Junya SUMITA ◽  
Taiyo MAKITA ◽  
Takashi TAKAGI ◽  
Eiji KUNIMOTO ◽  
...  
Keyword(s):  
High Temperature ◽  
Special Issue ◽  
Very High Temperature Reactor ◽  
High Temperature Reactor ◽  
Very High

Tritium Permeation Characterization of Materials for Fusion and Generation IV Very High Temperature Reactors

2015 ◽  
Vol 67 (3) ◽  
pp. 475-478
Author(s):  
S. Thomson ◽  
K. Pilatzke ◽  
K. McCrimmon ◽  
I. Castillo ◽  
S. Suppiah
Keyword(s):  
High Temperature ◽  
High Temperature Reactors ◽  
Tritium Permeation ◽  
Characterization Of Materials ◽  
Very High

scholarly journals Preparation and Characterization of Mg–Al–B Alloy (Mg0.5Al0.5B2) Via High-Temperature Sintering

Materials ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3608
Author(s):  
Lin Yang ◽  
Jie He ◽  
Yusong Ma ◽  
Liang Zhang ◽  
Shizhou Ma ◽  
...  
Keyword(s):  
Phase Composition ◽  
High Temperature ◽  
Sintering Temperature ◽  
Pure Aluminum ◽  
High Energy ◽  
Holding Time ◽  
Molar Ratio ◽  
Simple Substance ◽  
Improved Characteristics

Boron and its alloys have long been explored as potential fuel and increasingly replace pure aluminum powder in high-energy formulations. The ignition and burning properties of boron can be improved by making boron alloys. In this study, an Mg–Al–B alloy was synthesized from magnesium, aluminum and boron powders in a 1:1:4 molar ratio by preheating to 600 °C for 30 min, followed by high-temperature sintering in a tube furnace. The effects of sintering temperature (700–1000 °C) and holding time (0.5–10 h) on the phase composition of mixed powders were studied. After the samples were cooled to room temperature, they were ground into powder. The phase composition, micromorphology and the bonding forms of elements of the synthesized samples were studied using XRD, SEM and XPS. The results show that each element exists in the form of simple substance in the alloy. The influence of the sintering temperature on the synthesis reaction of Mg0.5Al0.5B2 is very important, but holding time has little effect on it. With the increase of sintering temperature, the content of the Mg0.5Al0.5B2 phase gradually increases, and the phase content of residual metal gradually decreases. The phase and morphology analyses show that the optimum sintering temperature is 1000 °C with a minimum holding time of 0.5 h. It is expected to be used in gunpowder, propellant, explosives and pyrotechnics with improved characteristics.

New Developments in Soluble Thermoplastic High Glass Transition Temperature Polyimides

1992 ◽  
Vol 264 ◽  
Author(s):  
M. E. Rogers ◽  
T. M. Moy ◽  
Y. J. Kim ◽  
J. E. McGrath
Keyword(s):  
Glass Transition ◽  
High Temperature ◽  
Transition Temperatures ◽  
New Developments ◽  
Glass Transition Temperatures ◽  
Transparent Films ◽  
Very High ◽  
End Group ◽  
Temperature Applications

AbstractUtilizing solution imidization, molecular weight and end group control techniques, soluble, fully cyclized polyimides with very high glass transition temperatures have been developed to meet high temperature applications. Mechanistic aspects are investigated for solution imidization by both the polyamic acid route and by the ester-acid route. Polyimides based on pyromellitic dianhydride and a 3F diamine exhibit glass transition temperatures of 420 °C. These polyimides are soluble in polar aprotic solvents and form tough, transparent films which demonstrate mechanical integrity and thermooxidative stability at 700 °F. Various processing routes are explored to demonstrate the viability of these materials in high temperature applications. Details of the synthesis and characterization of these materials will be provided.

OS0622 Characterization of 2D-C/C composite for application of Very High Temperature Reactor

2009 ◽  
Vol 2009 (0) ◽  
pp. 246-248
Author(s):  
Taiju SHIBATA ◽  
Junya SUMITA ◽  
Taiyo MAKITA ◽  
Takashi TAKAGI ◽  
Eiji KUNIMOTO ◽  
...  
Keyword(s):  
High Temperature ◽  
Very High Temperature Reactor ◽  
High Temperature Reactor ◽  
Very High

High-Temperature Structural Analysis of a Lab-Scale Alloy 800HT PCHE

2016 ◽  
Vol 713 ◽  
pp. 280-283 ◽  
Author(s):  
Kee Nam Song ◽  
Eung Seon Kim ◽  
S.Y. Jang
Keyword(s):  
High Temperature ◽  
Heat Exchanger ◽  
Structural Analysis ◽  
Structural Integrity ◽  
Production Plant ◽  
Test Conditions ◽  
Very High Temperature Reactor ◽  
Intermediate Heat Exchanger ◽  
High Temperature Reactor ◽  
Very High

The IHX (Intermediate Heat Exchanger) of a VHTR (Very High Temperature Reactor) transfers 950°C heat generated from the VHTR to a hydrogen production plant. The Korea Atomic Energy Research Institute has manufactured a lab-scale Alloy 800HT PCHE (Printed Circuit Heat Exchanger) prototype under consideration as a candidate of the IHX (Intermediate Heat Exchanger). In this study, as a part of a structural integrity evaluation of the PCHE prototype, an elasto-plastic structural analysis including a thermal analysis was carried out under the designed test conditions of the PCHE prototype in a helium experimental loop (HELP). The analysis results were reflected to re-design the pipeline layout of HELP and to determine the actual test conditions of the PCHE prototype in the re-designed HELP in view of experimental safety.

Use of LaB6 for a High Quality, Small Energy Spread Beam in an Electron Velocity Spectrometer

1976 ◽  
Vol 34 ◽  
pp. 534-535 ◽  
Author(s):  
P. E. Batson ◽  
C. H. Chen ◽  
J. Silcox
Keyword(s):  
High Temperature ◽  
Energy Resolution ◽  
Electron Velocity ◽  
Electronic Excitations ◽  
Small Energy ◽  
Small Intensity ◽  
Good Energy ◽  
Spectrometer System ◽  
Electron Energy Loss ◽  
Very High

Electron energy loss experiments combined with microscopy have proven to be a valuable tool for the exploration of the structure of electronic excitations in materials. These types of excitations, however, are difficult to measure because of their small intensity. In a usual situation, the filament of the microscope is run at a very high temperature in order to present as much intensity as possible at the specimen. This results in a degradation of the ultimate energy resolution of the instrument due to thermal broadening of the electron beam.We report here observations and measurements on a new LaB filament in a microscope-velocity spectrometer system. We have found that, in general, we may retain a good energy resolution with intensities comparable to or greater than those available with the very high temperature tungsten filament. We have also explored the energy distribution of this filament.

TEM study of boron additions to cobalt aluminide

1988 ◽  
Vol 46 ◽  
pp. 546-547
Author(s):  
Gerald B. Feldewerth
Keyword(s):  
High Temperature ◽  
Turbine Engines ◽  
Major Drawback ◽  
University Of Missouri ◽  
Specific Strength ◽  
Aerospace Applications ◽  
Wide Range ◽  
Ordered Alloys ◽  
The University ◽  
Very High

In recent years an increasing emphasis has been placed on the study of high temperature intermetallic compounds for possible aerospace applications. One group of interest is the B2 aiuminides. This group of intermetaliics has a very high melting temperature, good high temperature, and excellent specific strength. These qualities make it a candidate for applications such as turbine engines. The B2 aiuminides exist over a wide range of compositions and also have a large solubility for third element substitutional additions, which may allow alloying additions to overcome their major drawback, their brittle nature.One B2 aluminide currently being studied is cobalt aluminide. Optical microscopy of CoAl alloys produced at the University of Missouri-Rolla showed a dramatic decrease in the grain size which affects the yield strength and flow stress of long range ordered alloys, and a change in the grain shape with the addition of 0.5 % boron.

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