Heat-resistant RuAl-based alloys. Part II. Powder alloys — preparation by reaction sintering

2021 ◽  
Vol 1 ◽  
Author(s):  
K. B. Povarova ◽  
◽  
A. E. Morozov ◽  
A. V. Antonova ◽  
M. A. Bulakhtina ◽  
...  
Keyword(s):  
High Speed ◽  
Titanium Aluminides ◽  
Protective Coatings ◽  
Reaction Sintering ◽  
Promising Candidate ◽  
Heat Resistant ◽  
Pressure Application ◽  
Specialized Equipment ◽  
Temperature Time ◽  
Potential Use

Refractory (Tm = 2100 °C), heat-resistant ruthenium monoaluminide RuAl, lighter (ρ = 7.97 g/cm3) than Ni superalloys, is considered as a promising candidate material for operation at high temperatures and relatively low loads in high-speed gas oxidizing flows at temperatures higher not only the twork, but also the melting point of both nickel superalloys and nickel and titanium aluminides. RuAl is also an ideal candidate for potential use in protective coatings. In the second part of the article, the possibilities of obtaining alloys based on RuAl directly from the initial powders of ruthenium and aluminum are considered by combining the temperature-time modes of reaction sintering (RS), the sequence and intensity of pressure application during RS, without the use of specialized equipment for obtaining initial powders of a given composition and without restrictions on the particle size distribution of the original powders.

Heat-resistant RuAl-based alloys. III. Powder alloys — mechanical alloying

2021 ◽  
Vol 11 ◽  
pp. 5-19
Author(s):  
K. B. Povarova ◽  
◽  
A. E. Morozov ◽  
A. A. Drozdov ◽  
A. V. Antonova ◽  
...  
Keyword(s):  
Mechanical Alloying ◽  
High Speed ◽  
Titanium Aluminides ◽  
Protective Coatings ◽  
Alloy Formation ◽  
Promising Candidate ◽  
Melting Temperatures ◽  
Heat Resistant ◽  
Cast Alloys ◽  
Temperature Time

Refractory (Tmelt = 2100 °C), heat-resistant ruthenium monoaluminide RuAl, lighter (ρ = 7.97 g/cm3) than Ni superalloys, is considered as a promising candidate material for operation at high temperatures and relatively low loads in high-speed gas oxidizing flows at temperatures higher not only operating temperatures, but also the melting temperatures of both nickel superalloys and nickel and titanium aluminides. RuAl is also an ideal candidate for potential protective coatings. In the first part of the article, RuAl-based cast alloys were considered. In the second part of the article, the possibilities of obtaining alloys based on RuAl directly from the initial powders of ruthenium and aluminum are considered by combining the temperature-time regimes of reaction alloy formation (RA), the sequence and intensity of pressure application during RA. The third part of the article is devoted to studying the possibilities of using powders doped with RuAl (NiAl, TiAl) of a given composition, obtained by mechanical alloying, as a starting material.

Spraying Coatings by Supersonic Metallization

2000 ◽  
Author(s):  
I. Karp ◽  
A. Rudoy
Keyword(s):  
High Speed ◽  
Protective Coatings ◽  
Combustion Products ◽  
Arc Spraying ◽  
Supersonic Stream ◽  
Properties Of Coatings ◽  
Equipment Complex ◽  
Motor Component ◽  
Specialized Equipment ◽  
Hydrocarbon Gas

Abstract A technology and a specialized equipment complex based on supersonic arc spraying gun, where a supersonic stream of combustion products of hydrocarbon-gas (HC-gas) with air is used as an atomizing gas, have been developed. Durable and safe work of coated parts functioning under conditions of intensive loading is determined (except general requirement to coatings: wear resistance, hardness) to a large extent by the fatigue strength, porosity and stability of the properties of coatings. New possibilities for satisfying all the requirement to coatings on parts type are opened up by a high speed spraying of wire. This is provided at the expanse of raising the kinetic energy of particles under spray, increase of their concentration in metal stream, lowering of the spread of parameters in the vicinity of a substrate. This, in its turn, determines the increase of adhesive and cohesive strength of coating, the decrease of oxidation, the improvement of stability and reproducibility of its properties. The results of the investigations of the influence of the variable parameters of the process on the listed above properties of coatings are presented. This technology and equipment complex is appreciated for repair of wearied motor component and deposition of corrosion protective coatings.

An atomic-resolution microscope study of Al contracts on GaAs

1986 ◽  
Vol 44 ◽  
pp. 726-727
Author(s):  
Z. Liliental-Weber ◽  
C. Nelson ◽  
R. Ludeke ◽  
R. Gronsky ◽  
J. Washburn
Keyword(s):  
High Speed ◽  
Schottky Contacts ◽  
Detailed Knowledge ◽  
The Past ◽  
Semiconductor Interfaces ◽  
Deposited Metal ◽  
Microwave Applications ◽  
Free Interfaces ◽  
Potential Use

The properties of metal/semiconductor interfaces have received considerable attention over the past few years, and the Al/GaAs system is of special interest because of its potential use in high-speed logic integrated optics, and microwave applications. For such materials a detailed knowledge of the geometric and electronic structure of the interface is fundamental to an understanding of the electrical properties of the contact. It is well known that the properties of Schottky contacts are established within a few atomic layers of the deposited metal. Therefore surface contamination can play a significant role. A method for fabricating contamination-free interfaces is absolutely necessary for reproducible properties, and molecularbeam epitaxy (MBE) offers such advantages for in-situ metal deposition under UHV conditions

Composite cladded powders for spraying of protective coatings

2019 ◽  
pp. 59-64
Author(s):  
E. Yu. Gerashchenkova ◽  
T. I. Bobkova ◽  
E. A. Samodelkin ◽  
B. V. Farmakovsky
Keyword(s):  
Tungsten Carbide ◽  
Gas Phase ◽  
High Speed ◽  
Protective Coatings ◽  
Powder Materials ◽  
Nanosized Particles

The paper presents results of the development of technology for producing cladded and surfacealloyed powder materials. High-speed mechanosynthesis of matrix powders of FeCrAl and solid nanosized particles of tungsten carbide occurs in a disintegrator in the presence of an active gas phase (nitrogen).

Technology for producing composite nanostructured powder for protective coatings

2020 ◽  
pp. 97-103
Author(s):  
E. Yu. Geraschenkova ◽  
A. F. Vasiliev ◽  
E. A. Samodelkin ◽  
B. V. Farmakovsky
Keyword(s):  
Aluminum Powder ◽  
High Speed ◽  
Protective Coatings ◽  
Hadfield Steel ◽  
Nanostructured Powder ◽  
Powder Composition ◽  
Clad Powder

This article presents the results of the development of technology for producing clad powder and coatings based on it. The possibility of obtaining a clad powder using high-speed mechanosynthesis in disintegrator plants is shown on the example of the Hadfield steel – aluminum powder composition.

Diamond-Like Carbon Coating—It'S Application for Polymeric Substrates

1991 ◽  
Vol 239 ◽  
Author(s):  
Fred M. Kimock ◽  
Alex J. Hsieh ◽  
Peter G. Dehmer ◽  
Pearl W. Yip
Keyword(s):  
High Speed ◽  
Protective Coatings ◽  
Ion Beam ◽  
Chemical Exposure ◽  
Optical Systems ◽  
Impact Behavior ◽  
Organic Liquids ◽  
Diamond Like Carbon ◽  
Dlc Coating ◽  
The Impact

ABSTRACTWe report on a recently commercialized Diamond-Like Carbon (DLC) coating that has been deposited on polycarbonate at near room temperature, via a unique ion beam system. Aspects of high speed impact behavior, chemical resistance, abrasion resistance, and thermal stability of the coating are examined. Results of scanning electron microscopy studies indicate that adhesion of the DLC coating is very good; no delamination of the coating was found on ballistically tested specimens. The well-bonded DLC coating did not cause the impact performance of polycarbonate to become brittle. Chemical exposure test results show that the DLC coating is capable of protecting polycarbonate from chemical attack by aggressive organic liquids. These ion beam deposited DLC coatings have considerable potential as protective coatings for optical systems.

Seam Welds Modeling and Mechanical Properties Prediction in the Extrusion of AA6082 Alloy

2008 ◽  
Vol 367 ◽  
pp. 125-136 ◽  
Author(s):  
Lorenzo Donati ◽  
Luca Tomesani
Keyword(s):  
Mechanical Properties ◽  
High Speed ◽  
Fem Simulation ◽  
Die Design ◽  
Welding Parameters ◽  
Middle Section ◽  
3D Fem ◽  
Strain And Strain Rate ◽  
Mechanical Properties Prediction ◽  
Temperature Time

This work summarizes the outcome of recent research by the authors on modeling the formation of seam welds in aluminum extrusion and on evaluating the related mechanical properties on the final products. A profile with a seam weld in the middle section was produced with different die designs in order to investigate the relation between die design and local welding parameters, such as contact pressure, temperature, time of contact, strain and strain rate paths. The local welding conditions were evaluated by complete thermo-mechanical 3D FEM simulation of the processes. Specimens were extracted from the profiles and tensile tested, the resulting mechanical properties being discussed with respect to the local welding conditions. The possibility to adopt criteria for assessing the welding quality is discussed, together with the effect of high speed damage cracking.

Developmental Outcome Prediction From Acoustic Cry Analysis in Term and Preterm Infants

PEDIATRICS ◽  
1987 ◽  
Vol 80 (4) ◽  
pp. 529-534
Author(s):  
Barry M. Lester
Keyword(s):  
Fundamental Frequency ◽  
High Speed ◽  
Infant Development ◽  
Developmental Outcome ◽  
Term Infants ◽  
Perceptual Performance ◽  
The Mean ◽  
Speed Computer ◽  
Potential Use ◽  
Bayley Scales

It has been suggested that the cry may reflect the neurophysiologic integrity of the infant and relate to later developmental outcome. In this study, the cry was recorded at term conceptional age in 18 preterm and 13 term infants using a standardized procedure and analyzed by high-speed computer. At 18 months of age, a significant number of infants were correctly classified as scoring high or low on the Bayley Scales of Infant Development based on the mean and variability in the fundamental frequency, variability in the first formant, and the amplitude of the cry. At 5 years of age, a significant number of infants were correctly classified on the McCarthy General Cognitive Index and on the verbal, perceptual-performance, and quantitative subscales based on the variability of the fundamental frequency, variability of the first formant, and amplitude and duration of the cry. Although preliminary, this study supports the potential use of the cry as a noninvasive measure to detect developmental outcome in the infant at risk.

scholarly journals “Green” Synthesis and Antioxidant Activity of Thermally Stable Gold Nanoparticles Encapsulated in Carbon Nanosheets

2020 ◽  
Vol 10 (7) ◽  
pp. 2272
Author(s):  
Hui-Wen Lin ◽  
Jia-Yi Wang ◽  
Vincent K. S. Hsiao ◽  
Chih-Chien Chu
Keyword(s):  
Gold Nanoparticles ◽  
High Speed ◽  
Food Industry ◽  
Radical Scavenging ◽  
Green Method ◽  
Paramagnetic Resonance ◽  
Carbon Nanosheets ◽  
Electron Paramagnetic ◽  
Dpph Radical Scavenging ◽  
Potential Use

We have developed a “green” method for fabricating gold nanoparticles (AuNPs) through biogenic approaches. The proposed method has the advantages of facile preparation under ecofriendly conditions. AuNPs encapsulated in carbon nanosheets, and exhibiting high thermal stability, were fabricated by autoclaving pectin-capped AuNPs, which were subsequently collected through high-speed centrifugation and redispersed in aqueous solution. The 1,1-diphenyl-2-picrylhydrazy (DPPH) radical scavenging assay indicated that our prepared AuNPs exhibited more prolonged antioxidant capacity than pristine apple extracts. Electron paramagnetic resonance (EPR) spectra showed that approximately 80% of DPPH radicals were scavenged by the pectin-capped AuNPs at a concentration of 3 mg/mL. According to our results, AuNPs prepared through biogenic approaches have potential use in the food industry.

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