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.

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.

Formation of Si0.80Ge0.20 Solid Solution by Mechanical Alloying

2010 ◽  
Vol 660-661 ◽  
pp. 341-346
Author(s):  
Y.A. Chen ◽  
Cosme Roberto Moreira Silva ◽  
D. Michael Rowe
Keyword(s):  
Mechanical Alloying ◽  
Figure Of Merit ◽  
Oxide Dispersion Strengthened ◽  
High Energy ◽  
Charge Ratio ◽  
Alloy Formation ◽  
Pure Silicon ◽  
Melting Temperatures ◽  
Silicon And Germanium ◽  
The Individual

In general, semiconductor materials for thermoelectric generation prepared by vacuum metallurgy shows a relatively high value of figure-of-merit. However, differences in some properties of alloys elemental constituents can cause processing problems. Recently, Mechanical Alloying (MA) has been used to produce polycrystalline thermoelectric materials, such as (Bi,Sb)2 and (Te,Se)3(1). The industry is using this process since early 70’s to produce oxide dispersion strengthened alloys and those with widely different melting temperatures (2) In the present work, Si0.80Ge0.20 alloys were prepared via Mechanical Alloying (MA), using 99.9 % pure silicon and germanium powders, with a sieve size of 100 mesh. The MA has been performed, for several balls - to - powder ratio, in a SPEX 8000 vibratory high energy milling with tungsten carbide balls. Time for alloy formation was in a range from 3 to 9 hours, corresponding to charge ratio of 12:1 and 4:1, respectively. After two hours of processing time, the grinding temperature reached 80 0 C, and remained at this level until the end of the process. It was possible to follow the SiGe alloy formation by x-ray diffractometry, as the peak lines positions of elemental Si and Ge were continuously shifted, and end up to merge into a single broad peak. There was a convergence of the individual lattice parameters of Si and Ge to a single value of 5.470 A, measured within the limit of  0.005 A. For the Si0.80Ge0.20 system evaluated in this work, the alloying progress occurred continuously, and changed inversely with charge ratio.

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.

A Fracture Mechanics Approach to the Prediction of Tool Wear in Dry High Speed Machining of Aluminum Cast Alloys: Part 2 — Model Calibration and Verification

Tribology ◽  
2005 ◽  
Author(s):  
Alexander Bardetsky ◽  
Helmi Attia ◽  
Mohamed Elbestawi
Keyword(s):  
Fracture Mechanics ◽  
Tool Wear ◽  
Model Calibration ◽  
High Speed ◽  
Cutting Conditions ◽  
Depth Of Cut ◽  
High Speed Machining ◽  
Wear Model ◽  
Wide Range ◽  
Cast Alloys

Experimental study has been carried out to establish the effect of cutting conditions (speed, feed, and depth of cut) on the cutting forces and time variation of carbide tool wear data in high-speed machining (face milling) of Al-Si cast alloys that are commonly used in the automotive industry. The experimental setup and force measurement system are described. The test results are used to calibrate and validate the fracture mechanics-based tool wear model developed in Part 1 of this work. The model calibration is conducted for two combinations of cutting speed and a feed rate, which represent a lower and upper limit of the range of cutting conditions. The calibrated model is then validated for a wide range of cutting conditions. This validation is performed by comparing the experimental tool wear data with the tool wear predicted by calibrated cutting tool wear model. The prediction errors were found to be less then 7%, demonstrating the accuracy of the object oriented finite element (OOFE) modeling of the crack propagation process in the cobalt binder. It also demonstrates its capability in capturing the physics of the wear process. This is attributed to the fact that the OOF model incorporates the real microstructure of the tool material.

Heat Treatment of Heat-Resistant Ferrous Cast Alloys

2015 ◽  
Vol 9 (2) ◽  
pp. 7-20 ◽  
Author(s):  
Delin Li ◽  
Clayton Sloss
Keyword(s):  
Heat Treatment ◽  
Heat Resistant ◽  
Cast Alloys

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.

Sign in / Sign up

Export Citation Format

Share Document