scholarly journals Materials for Gas-Thermal Spraying, Obtained by Diffusion Alloying from Powders Based on Austenitic Steels

2019 ◽  
Vol 18 (5) ◽  
pp. 380-385
Author(s):  
F. I. Panteleenko ◽  
V. A. Okovity ◽  
A. F. Panteleenko
Keyword(s):  
Powder Material ◽  
Experimental Studies ◽  
Thermal Spraying ◽  
Thermal Exposure ◽  
Treatment Temperature ◽  
Austenitic Steels ◽  
Alloying Elements ◽  
Powder Materials ◽  
Boride Phase ◽  
Boride Phases

The article presents experimental studies of composite powder materials for plasma spraying, obtained by the method of diffusion doping of powder materials based on austenitic steels. It is indicated that the main factors forming the diffusion layer on a powder material are a composition of the required saturating medium, treatment temperature and duration of chemical and thermal exposure. Creation of single-phase diffusion layers is possible only in the case of a minimum level of temperature-time characteristics during heat treatment. This is also facilitated by the use of media with a low concentration of boron and introduction of additives inhibiting saturation process (such as carbon, aluminum, silicon) into a saturating mixture of powder. Structure and composition of powders have been thoroughly investigated with the help of X-ray microanalysis that has made it possible to study location of elements contributing to powder alloying and micro-durametric characteristics. A component of high-boride phase is increasing due to higher degree of powder material alloying. Significant changes in phase composition, as well as the chemical one, are noticeable in diffusion processing of the following alloyed powder materials: РR-Х18N9, РR-Х18N10, РR-Х18N15. Free carbon being displaced by boride into a transition zone creates dispersed complex carbide compounds with chromium. This is confirmed by distribution nature of carbide-forming components in a powder particle. All carbide-forming elements have characteristic concentration peaks-bursts in contrast to non-carbideforming silicon. Silicon is practically not present in the considered FeB phase and it is found only in a very small amount in the studied Fe2B phase; it is pushed aside by high-boride phases to a sublayer. The change in microhardness of the FeB and Fe2B phases under study is associated with dissolution of corresponding alloying elements in them and distortions of a crystal lattice in borides. A similar phenomenon is also characteristic for saturation while using boron or while making chemical and thermal treatment of alloyed steels, it has been noted in a number of studies. The increase in microhardness of a particle nucleus during its boriding is caused by displacement of carbon and alloying elements by growing front of boride phases. A core zone moves with an increased microhardness to a particle core while increasing temperature mode and time of boronization and up to realization of the effect with counter diffusion.

New Powdered Silicide Materials for Thermal Spraying Process and Coatings on the Niobium Base Alloys

1998 ◽  
Author(s):  
V. Terentieva ◽  
O. Bogatchkova ◽  
D. Cornu
Keyword(s):  
Protective Coating ◽  
Protective Coatings ◽  
Thermal Spraying ◽  
Base Material ◽  
Theory And Practice ◽  
Powder Materials ◽  
Self Healing ◽  
High Enthalpy ◽  
Boride Phases ◽  
Spraying Process

Abstract The given article presents some results of the scientific research devoted to the development of a new class of scale-resistant powder materials of the Si-Ti-Mo-B system for thermal spraying and using these materials for the creation of heat-resistant coatings on the niobium base alloys by means of various methods of thermal spraying. Also under consideration are problems relating to the theory and practice of obtaining reliable protective coatings on high-melting metals and their alloys, niobium ones included, intended for operation in high-enthalpy oxygen-containing gas flows. Hazard in commencing an oxidation reaction of the base material under coating is connected with density of open pores and cracks, and partial pressure of the oxidizer. Powdered multicomponent heterophase materials for gas-thermal spraying of protective coating with a self-healing ability and controlled properties are proposed. Finally the results of some properties of new silicide-type heterophase powders containing silicide and boride phases for a thermal spraying process and some properties of protective coating deposited on the niobium base alloys by means of a thermal spraying technique are presented.

scholarly journals The Effect of Vibro-Finishing Treatment on The Porosity of the Surface Layer of Powder Metallurgy Products

2019 ◽  
Vol 297 ◽  
pp. 04006
Author(s):  
Yuriy Ankudimov ◽  
Irina Sadovaya ◽  
Dieudonne Essola ◽  
Tatyana Bagdasaryan
Keyword(s):  
Surface Layer ◽  
Powder Metallurgy ◽  
Powder Material ◽  
Functional Dependence ◽  
Particle Interaction ◽  
Experimental Studies ◽  
Surface Plastic Deformation ◽  
Powder Materials ◽  
Surface Plastic ◽  
Porosity Reduction

The article is devoted to the methods of surface plastic deformation treatment to change the porosity of parts obtained from powder materials. Functional dependences between the concentration of the solid part of the system and the size of the plastic print on the example of vibro-finishing and hardening treatment (VF and HT) are established. The reduction in porosity upon hardening of the surface material is experimentally confirmed. The results can be used to predict the surface porosity of powder metallurgy products that have undergone additional processing of SPD, as well as for further studies of the field of application of (VF and HT). Based on the particle interaction in the working medium with the part surface made from powder material, we obtained functional dependence of the density coefficient of the surface layer of the powder material after (VF and HT). Experimental studies were carried out on samples of powdered iron PK6. The porosity of the samples was determined by stereoscopic metallography, microhardness of the surface layer - on hardness tester. Everything was performed by standard methods. The results were presented in a series of porosity charts. Maximum hardening is 30% of almost twofold porosity reduction. The experts in the field of powder metallurgy may be interested in the obtained results.

Effect of Extended Thermal Exposure and Alloying Elements on the Morphology of Eutectic Si in Al–Si Cast Alloys

2020 ◽  
Vol 14 (4) ◽  
pp. 1013-1024 ◽  
Author(s):  
M. H. Abdelaziz ◽  
A. M. Samuel ◽  
H. W. Doty ◽  
F. H. Samuel
Keyword(s):  
Thermal Exposure ◽  
Alloying Elements ◽  
Eutectic Si ◽  
Cast Alloys

Effective Porosity Comparison with a Lime Mortar Matrix Base during 350 to 700 Days

2017 ◽  
Vol 902 ◽  
pp. 60-64
Author(s):  
Judith Alejandra Velázquez Perez ◽  
Wilfrido Martínez Molina ◽  
Hugo Luis Chávez García ◽  
Elia Mercedes Alonso Guzmán ◽  
Rosalía Ruiz Ruiz
Keyword(s):  
Powder Material ◽  
Effective Porosity ◽  
Capillary Absorption ◽  
Powder Materials ◽  
Maize Starch ◽  
Lime Mortar ◽  
Historical Sites ◽  
Matrix Base ◽  
Weight Proportion ◽  
Mortar Matrix

This research is an investigation about the use of powder material additions with mortars lime base for a possible implementation in construction and/or restoration of historical sites. Mortars were elaborated in laboratory conditions with a 1:2.5 in weight proportion. One of the proofs to which these mortars were submitted was the test of capillary absorption; this way, the influence of the materials added to powder in these mortars determined porosity. Mortars were made with different percentages of materials. These powder materials are brick manufacturing ash, quarry powder, clay and maize starch. The test was run during 350 to 700 days. It obtained better results with 700 days than with 350 days.

Effects of Gun Nozzle Geometry on High Velocity Oxygen-Fuel (HVOF) Thermal Spraying Process

1998 ◽  
Author(s):  
K. Sakaki ◽  
Y. Shimizu ◽  
Y. Gouda ◽  
A. Devasenapathi
Keyword(s):  
Numerical Simulation ◽  
Experimental Studies ◽  
Thermal Spraying ◽  
Deposition Efficiency ◽  
Divergence Angle ◽  
Nozzle Geometry ◽  
Oxide Content ◽  
Hvof Thermal Spraying ◽  
Throat Diameter ◽  
Spraying Process

Abstract Effect of nozzle geometry (such as throat diameter of a barrel nozzle, exit diameter and exit divergence angle of a divergent nozzle) on HVOF thermal spraying process (thermodynamical behavior of combustion gas and spray particles) was investigated by numerical simulation and experiments with Jet KoteTM II system. The process changes inside the nozzle as obtained by numerical simulation studies were related to the coating properties. A NiCrAIY alloy powder was used for the experimental studies. While the throat diameter of the barrel nozzle was found to have only a slight effect on the microstructure, hardness, oxygen content and deposition efficiency of the coatings, the change in divergent section length (rather than exit diameter and exit divergence angle) had a significant effect. With increase in divergent section length of the nozzle, the amount of oxide content of the NiCrAIY coatings decreased and the deposition efficiency increased significantly. Also, with increase in the exit diameter of the divergent nozzle, the gas temperature and the degree of melting of the particle decreased. On the other hand the calculated particle velocity showed a slight increase while the gas velocity increased significantly.

scholarly journals Effect of Fullerenes Additions on Physical – Mechanical Properties of Hot-Forged Iron-Based Powder Materials

2021 ◽  
Vol 877 (1) ◽  
pp. 012009
Author(s):  
Mohammed Qasim Kareem ◽  
Vladimir Dorofeyev
Keyword(s):  
Powder Material ◽  
Testing Machine ◽  
Hot Forging ◽  
Hardness Test ◽  
Carbon Steels ◽  
Powder Materials ◽  
Test Machine ◽  
Technological Parameters ◽  
Volume Weight ◽  
Iron Based

Abstract It is possible to expand the applications ranges of powder material products by enhancing the performance properties of these products in addition to their manufacturability and reliability together, it’s possible by materials structures modification. In this paper, the effect of fullerene (C60) additives to iron-based powder material has been studied. All samples produced by Hot-Forging (HF) powder materials technology. Green and HF density of the obtained samples calculated by volume / weight and Archimede’s principle, respectively. The effect of technological parameters on the microstructure of carbon steels’ samples was done by an ALTAMI MET-1M metallographic microscope. Tensile test executed by using of a universal testing machine UMM –5 and the microhardness (HV10) was measured by REICHERT hardness test machine. The results showed that the HF C60 steels’ samples had higher density and strength of 0.81 and 25%, respectively, with a good plasticity in comparison with graphite steels’ samples.

scholarly journals Simulation of Thermoplastic Powder Cold Spraying

2021 ◽  
Vol 14 (6) ◽  
pp. 726-734
Author(s):  
Tatyana A. Brusentseva ◽  
◽  
Vladislav S. Shikalov ◽  
Sergei M. Lavruk ◽  
Vasily M. Fomin
Keyword(s):  
Gas Flow ◽  
Experimental Studies ◽  
Cold Spraying ◽  
Deposition Efficiency ◽  
Powder Materials ◽  
Stagnation Temperature ◽  
Computational Domain ◽  
Ansys Fluent ◽  
Process Gas ◽  
Spray Method

The work is devoted to the deposition of composite powder materials by cold spray method. As a spraying material, a thermoplastic compound «WAY» for marking the roadway was used. An asphalt concrete was used as a substrate. As a result of experimental studies, the dependence of the deposition efficiency on the stagnation temperature of the working air in the ejector nozzle was obtained. The ANSYS Fluent package was used for evaluative modeling of the cold spraying process. Gas flow patterns were obtained in the computational domain without particles and taking into account the interaction of the flow with particles. The trajectory of the particles was calculated for various spraying parameters

scholarly journals X-RAY SPECTRAL MICROANALYSIS OF ELECTROEROSIVE POWDER MATERIAL OBTAINED IN AN ETHYL ALCOHOL MEDIUM FROM WASTE OF A NON-TUNGSTEN HARD ALLOY OF THE KNT16 BRAND

2020 ◽  
pp. 33-36
Author(s):  
E. V. Ageeva ◽  
B. N. Sabel’nikov
Keyword(s):  
Hard Alloy ◽  
Powder Material ◽  
Ethyl Alcohol ◽  
Scientific Research ◽  
Powder Materials ◽  
Hard Alloys ◽  
Processing Waste ◽  
Resource Saving ◽  
X Ray ◽  
Alcohol Medium

The first appearance of tungsten-free hard alloys (TFHA) was noted in the early 30s of the last century, but they did not receive due attention and, accordingly, spread due to insufficient strength and were replaced by tungsten-containing alloys of such groups as VK, TC and TTK. However, the rapidly developing shortage of expensive tungsten pushed in the late 50s to return to the search for hard alloys, the composition of which does not include tungsten. Due to the growing demand for tungsten-free hard alloys, the problem of recycling their waste with the possibility of reuse is acute in the industry. The purpose of this work was to conduct x-ray spectral microanalysis (RSMA) of powder material (PM) obtained by electroerosive dispersion (EED) in ethyl alcohol from waste of a non-tungsten hard alloy of the KNT16 brand. The resulting powder material was examined using an energy-dispersion x-ray analyzer from EDAX, built into a scanning electron microscope "QUANTA 600 FEG". In the course of scientific research, the spectra of characteristic x-ray radiation on the surface of the experimentally obtained sample were obtained. The results obtained in the course of scientific research can be used to create environmentally friendly resource-saving processes for processing waste of tungsten-free hard alloys into powder materials.

Effect of Substitutional Alloying Elements on the Stacking Fault Energy in Austenitic Steels

2021 ◽  
Vol 2021 (10) ◽  
pp. 1325-1332
Author(s):  
V. M. Blinov ◽  
I. O. Bannykh ◽  
E. I. Lukin ◽  
O. A. Bannykh ◽  
E. V. Blinov ◽  
...  
Keyword(s):  
Stacking Fault ◽  
Stacking Fault Energy ◽  
Austenitic Steels ◽  
Alloying Elements

Structure and properties of powders obtained by electrodispersion of corrosion-resistant metal waste in kerosine

2021 ◽  
pp. 276-281
Author(s):  
E.V. Ageeva ◽  
E.V. Ageev ◽  
A.A. Sysoev
Keyword(s):  
High Efficiency ◽  
Experimental Studies ◽  
Low Energy ◽  
Powder Materials ◽  
Energy Costs ◽  
Structure And Properties ◽  
Corrosion Resistant ◽  
High Chromium ◽  
Metal Waste ◽  
Industrial Use

The results of experimental studies of the structure and properties of electroerosive high-chromium powders obtained in kerosene are presented. The high efficiency of using the electrodispersing technology is shown, which provides for obtaining new corrosion-resistant powder materials suitable for industrial use at low energy costs.

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