The effect of gas atmosphere on the coating formation by electric arc surfacing with cermet SHS electrodes of the TiB2–Co2B composition

2021 ◽  
Vol 6 (3) ◽  
pp. 216-224
Author(s):  
Alexandra O. Zhidovich ◽  
Alexander M. Stolin ◽  
Andrey P. Chizhikov ◽  
Pavel M. Bazhin ◽  
Alexander S. Konstantinov
Keyword(s):  
Phase Composition ◽  
Metal Matrix ◽  
Protective Coatings ◽  
Steel Substrate ◽  
Nitrogen Atmosphere ◽  
Electric Arc ◽  
Argon Atmosphere ◽  
Shs Extrusion ◽  
Wide Range ◽  
Gas Atmosphere

Due to their unique properties, metal-matrix composite materials, when used as a surfacing material for electric arc surfacing, provide high properties of the deposited layers. SHS-extrusion is a promising method for a wide range of surfacing metal-matrix electrodes. The gas environment of surfacing affects the quality of coatings formed by SHS electrodes, their microstructure and properties. In this paper, cermet SHS electrodes of the TiB2–Co2B composition obtained by SHS-extrusion were used to form protective coatings on a steel substrate by electric arc surfacing in an argon atmosphere and in a nitrogen atmosphere. The elemental and phase composition, as well as the microstructure of the deposited layers, were investigated. Based on the conducted studies, the influence of the gas atmosphere on the formation of the structure of cermet coatings was established. It is shown that, despite the similar phase composition, there are fundamental differences in the microstructures of the deposited coatings, which are caused by the partial fusion of the tungsten electrode and the transfer of the electrode material in the coating during surfacing in an argon atmosphere. The maximum values of the microhardness of coatings deposited in a nitrogen atmosphere exceed the maximum microhardness of coatings obtained by surfacing in an argon atmosphere by 200–450 HV.

scholarly journals Making Ceramic Protective Coatings on Titanium Boride Base by Electric Arc Surfacing with SHS Electrodes in an Argon Atmosphere

2020 ◽  
pp. 012-016
Author(s):  
A.O. Zhidovich ◽  
◽  
A.M. Stolin ◽  
P.M. Bazhin ◽  
A.S. Konstantinov ◽  
...  
Keyword(s):  
Phase Composition ◽  
Layered Structure ◽  
Protective Coatings ◽  
Titanium Substrate ◽  
Titanium Boride ◽  
Electric Arc ◽  
Argon Atmosphere ◽  
Argon Flow ◽  
Flow Intensity ◽  
Arc Current

SHS extruded TiB / 30 wt.% Ti-layered long rods with a length of more than 100 mm and a diameter of 3 mm were made by electric arc surfacing on a titanium substrate in an argon atmosphere. Technological modes of coating deposition (electric arc current, arc speed, argon flow intensity, etc.) have been worked out by the method of electric arc surfacing. The structure and phase composition of the initial surfacing electrode and coating are investigated. It is shown that the deposited coating has a layered structure, its microstructure is represented by titanium diboride and monoboride in a matrix consisting of a solid boron in titanium solution. It was found that the structure and phase composition of the coating are predominantly identical to the structure and phase composition of the used SHS electrodes. The microhardness of the deposited electrode and coating was 1024 and 1420 HV, respectively.

scholarly journals Production of target cathodes from composite silicides for applying protective coatings using casting and deformation technologies

2021 ◽  
pp. 68-75
Author(s):  
I. A. Ivanov ◽  
A. G. Slutsky ◽  
V. A. Scheinert ◽  
A. I. Ivanov ◽  
A. N. Bely
Keyword(s):  
Protective Coatings ◽  
Pure Metal ◽  
Electric Arc ◽  
Argon Atmosphere ◽  
Raw Material ◽  
Induction Melting ◽  
Identical Composition ◽  
Arc Evaporation ◽  
Percentage Ratio ◽  
Shs Method

The article discusses the results of manufacturing multicomponent consumable cathodes of vacuum electric arc evaporation plants. To obtain ingots of complex silicide as a raw material for the manufacture of target cathodes, it is proposed to use induction melting of pure metal charge materials in an argon atmosphere.The method made it possible to obtain ingots of complex silicide with a composition close to the calculated one and a density of at least 93 %. Further forming of the cathode takes place when controlling the powder fractions by their percentage ratio with a pressing force of at least 50 tons. The results obtained are compared with the SHS method of manufacturing cathodes of identical composition.

scholarly journals Microstructure and magnetic properties of Nd-Fe-B-(Re, Ti) alloys

Nukleonika ◽  
2015 ◽  
Vol 60 (1) ◽  
pp. 29-33
Author(s):  
Mariusz Hasiak
Keyword(s):  
Magnetic Properties ◽  
Phase Composition ◽  
Volume Fraction ◽  
Magnetic Characteristics ◽  
Ti Alloys ◽  
Wide Range ◽  
Magnetically Hard ◽  
Ti Addition ◽  
Microstructure And Magnetic Properties

Abstract The microstructure and magnetic properties of nanocomposite hard magnetic Nd-Fe-B-(Re, Ti) materials with different Nd and Fe contents are studied. The role of Re and Ti addition in phase composition and volume fraction of the Nd-Fe-B phase is determined. All samples are annealed at the same temperature of 993 K for 10 min. Mössbauer spectroscopy shows that the addition of 4 at.% of Re to the Nd8Fe78B14 alloy leads to creation of an ineligible amount of the magnetically hard Nd2Fe14B phase. Moreover, the microstructure and magnetic characteristics recorded in a wide range of temperatures for the Nd8Fe79−xB13Mx (x = 4; M = Re or Ti) alloys are also analyzed.

scholarly journals Aluminum metal matrix composites a review of reinforcement; mechanical and tribological behavior

2018 ◽  
Vol 7 (2.4) ◽  
pp. 117 ◽  
Author(s):  
Pranav Dev Srivyas ◽  
M S. Charoo
Keyword(s):  
Metal Matrix ◽  
Tribological Behavior ◽  
Coefficient Of Thermal Expansion ◽  
Aluminum Matrix ◽  
Weight Ratio ◽  
High Hardness ◽  
Aluminum Matrix Composites ◽  
Matrix Composites ◽  
Wide Range ◽  
Structural Applications

This review aims to explore the fundamental mechanical and tribological behavior Aluminum matrix composites (AMCs) reinforced with different reinforcements. Aluminum matrix composites are considered to be the new emerging class of materials which are having the tailored properties for specific applications. AMCs are the advanced engineering materials having superior properties as comparison to other conventional aluminum alloys. AMCs exhibits attractive properties such as high hardness, better yield strength, strength to weight ratio, high thermal conductivity, low coefficient of thermal expansion, superior wear and corrosion resistance. In recent times, because of these properties they have repealed keen interest for various potential applications in aerospace, automotive and various other structural applications.. Extensive research and development has been made in the Al-based MMCs with every possible alloy and different reinforcements so as to get the material of desired properties. By suitable use of different reinforcements in the Al metal matrix a wide range of properties combination can be obtained. The fundamental mechanical and tribological behavior of different reinforcements under dry and wet lubricated sliding conditions is recently being studied. It is reported that various reinforcement were successfully employed to decrease friction and wear in various applications. A comprehensive review is provided with the aim to analyze such properties of different reinforcements. 

scholarly journals Influence of Aluminum and Molybdenum on the Microstructure and Corrosion Behavior of Thermally Sprayed High-Entropy Alloy Coatings

2021 ◽  
Author(s):  
Martin Löbel ◽  
Thomas Lindner ◽  
Maximilian Grimm ◽  
Lisa-Marie Rymer ◽  
Thomas Lampke
Keyword(s):  
Corrosion Resistance ◽  
Protective Coatings ◽  
Base Alloy ◽  
Alloy System ◽  
High Entropy Alloy ◽  
Oxide Content ◽  
Face Centered Cubic ◽  
High Entropy ◽  
Structural And Functional Properties ◽  
Wide Range

AbstractHigh-entropy alloys (HEAs) have shown a wide range of promising structural and functional properties. By the application of coating technology, an economical exploitation can be achieved. The high wear and corrosion resistance of HEAs make them particularly interesting for the application as protective coatings. Especially for alloys with a high chromium content, a high corrosion resistance has been revealed. For the current investigations, the equimolar HEA CrFeCoNi with a single-phase face centered cubic structure is considered as a base alloy system. To increase the corrosion resistance as well as the hardness and strength, the influence of the alloying elements aluminum and molybdenum is analyzed. For the current investigations, the high kinetic process high-velocity oxygen fuel thermal spraying (HVOF) has been considered to produce coatings with a low porosity and oxide content. Feedstock is produced by inert gas atomization. The influence of the alloy composition on the microstructure, phase formation and resulting property profile is studied in detail. A detailed analysis of the corrosion resistance and underlying mechanisms is conducted. The pitting and passivation behavior are investigated by potentiodynamic polarization measurements in NaCl and H2SO4 electrolyte. A distinct improvement of the corrosion resistance can be achieved for the alloy Al0.3CrFeCoNiMo0.2.

scholarly journals Barite-containing radiation protective building materials

2020 ◽  
Vol 21 (1) ◽  
pp. 94-98
Author(s):  
Nikolay V. Novikov ◽  
Svetlana V. Samchenko ◽  
Galina E. Okolnikova
Keyword(s):  
Building Materials ◽  
Protective Coatings ◽  
Relevant Literature ◽  
Cost Effective ◽  
Nuclear Facilities ◽  
Linear Absorption ◽  
Environmental Friendliness ◽  
Operational Characteristics ◽  
Wide Range ◽  
The Creation

Due to the active development of industries using nuclear technology, the creation of highly effective and cost-effective building materials for protection against hazardous ionizing radiation is of increasing interest. Widespread in the field of radiation-protective building materials are barite-containing concrete. The purpose of this article is to establish the prospects of their use in nuclear facilities, as well as to find ways to improve their technical and operational characteristics. For this an analysis of relevant literature and scientific research in the field of radiation-protective materials and, in particular, barite-containing concrete was carried out. The advantages of barite-containing concrete are high radiation-protective properties, environmental friendliness, high density, as well as economic indicators. The disadvantages are high susceptibility to shrinkage deformation and poor resistance to cyclic temperature effects. The addition of barite to the concrete composition allows to increase the coefficient of linear absorption of -rays of the material; also, with the proper selection of the composition, such material may have strength characteristics equal to or superior to the characteristics of concrete with standard compositions. Barite-containing materials have a wide range of applications and can be used both for the production of heavy concrete in the construction of load-bearing structures and in the creation of radiation-protective coatings for walls and floors.

Preparation and Microwave Permittivity of SiC-AlN Solid Solution Powders

2007 ◽  
Vol 336-338 ◽  
pp. 310-312
Author(s):  
Xiao Kui Liu ◽  
Wan Cheng Zhou ◽  
Fa Luo ◽  
Dong Mei Zhu
Keyword(s):  
Solid Solution ◽  
High Temperature ◽  
Carbon Black ◽  
Atomic Ratio ◽  
Nitrogen Atmosphere ◽  
Argon Atmosphere ◽  
Temperature Synthesis ◽  
High Temperature Synthesis ◽  
Microwave Permittivity ◽  
Shs Method

SiC-AlN solid solution powders were prepared from the mixtures of aluminum, silicon and carbon black in a nitrogen atmosphere with preheating self-propagating high temperature synthesis (SHS) method. The powders synthesized with different ratios of Al/Si were mixed with paraffin wax and the microwave permittivity of the mixtures was measured at the frequency of 8.2~12.4GHz. The results were contrasted with that of SiC powders synthesized by preheating SHS in argon and nitrogen atmosphere respectively. The ε′, ε″, and the tgδ (ε″/ε′) of the mixture of SiC prepared in a nitrogen atmosphere are highest, followed with those of the SiC-AlN solid solution powders and the SiC powders prepared in an argon atmosphere. Along with the increase of atomic ratio of Al/Si, the ε′, ε″, and tgδ of SiC-AlN solid solution decrease. We believe that, with the increase of AlN dissolved, the concentration of carriers and the effect of dielectric relaxation will decrease because of the two contrary dopants.

Phase composition and formation mechanisms of a high-velocity electric arc-sprayed FeNiCrAl coating

2018 ◽  
Vol 769 ◽  
pp. 998-1006 ◽  
Author(s):  
Haoliang Tian ◽  
Changliang Wang ◽  
Mengqiu Guo ◽  
Zhihui Tang ◽  
Shicheng Wei ◽  
...  
Keyword(s):  
Phase Composition ◽  
High Velocity ◽  
Electric Arc ◽  
Formation Mechanisms

Corrosion Resistance of Electroless Ni-P-W/ZrO2 Nanocomposite Coatings in Peracid Solutions

2022 ◽  
Vol 1048 ◽  
pp. 72-79
Author(s):  
Suriaya Hassan ◽  
Abdul Ansari ◽  
Arvind Kumar ◽  
Munna Ram ◽  
Sulaxna Sharma ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
Steel Substrate ◽  
Cost Effective ◽  
Argon Atmosphere ◽  
Nanocomposite Coatings ◽  
Second Phase ◽  
Effective Option ◽  
P Matrix ◽  
Electroless Ni ◽  
Mild Steel Substrate

In current investigation, the Ni-P-W/ZrO2 electroless nanocomposite coatings are deposited upon mild steel substrate (AISI 1040 grade). The W/ZrO2 nanoparticles (50 to 130 nm range) were incorporated separately into acidic electroless Ni-P matrix as a second phase materials. The as-plated EL Ni-P-W/ZrO2 depositions were also heated at 400 οC in Argon atmosphere for one hour duration and analyzed by SEM/EDAX and XRD physical methods. The Ni-P-W/ZrO2 as-plated coupons revealed nebulous type structures while heated coupons showed crystalline structures in both cases. Furthermore Ni-P-ZrO2 coatings have very less cracks and gaps as compared to Ni-P-W coatings. The corrosion tests result in peracid (0.30 ± 0.02 % active oxygen) solutions point up that corrosivity of peracid ( 500 ppm Cl) is more than peracid (0 ppm Cl) and corrosion resistance of tested coupons varies as Ni-P-ZrO2 (as-plated) > Ni-P-ZrO2 (heated) > Ni-P-W (as-plated) > Ni-P-W (heated) > MS. The utilization of Ni-P-ZrO2 nanocomposite coatings in peracid solutions can be considered a cost effective option on the basis of its better cost/strength ratio in addition to its fair corrosion resistance.

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