Composite alloy based on Co–Cr–Si–Zr–TiB2–BN system for nanostructured powders and functional coatings

Author(s):  
A. N. Skvortsova ◽  
T. I. Bobkova ◽  
B. V. Farmakovsky ◽  
V. N. Klimov ◽  
A. I. Dmitryuk

The paper studies the preparation of a composite nanostructured powder manufactured from an alloy of Co–Cr–Si–Zr–TiB2–BN system and describes functional coatings with high microhardness and corrosion resistance based on that powder. 

Materials ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2621
Author(s):  
Aneta Bartkowska

The paper presents the results of a study of the microstructure, chemical composition, microhardness and corrosion resistance of Cr-B coatings produced on Vanadis 6 tool steel. In this study, chromium and boron were added to the steel surface using a laser alloying process. The main purpose of the study was to determine the impact of those chemical elements on surface properties. Chromium and boron as well as their mixtures were prepared in various proportions and then were applied on steel substrate in the form of precoat of 100 µm thickness. Depending on the type of precoat used and laser processing parameters, changes in microstructure and properties were observed. Coatings produced using precoat containing chromium and boron mixture were characterized by high microhardness (900 HV0.05–1300 HV0.005) while maintaining good corrosion resistance. It was also found that too low laser beam power contributed to the formation of cracks and porosity.


2012 ◽  
Vol 533 ◽  
pp. 91-97 ◽  
Author(s):  
Andrei Manzat ◽  
A. Killinger ◽  
R. Gadow

Rising demands for ecologically friendly automotive engines require a significant decrease in fuel consumption and emissions. Also the recent trend of downsizing engines demands for high performance materials for internal combustion engine applications. Tribologically functional coatings applied by supersonic flame spraying help in boosting the engine efficiency by reducing the internal friction and improving the durability and wear resistance of the cylinder running surface much-needed for engine downsizing tasks together with a high corrosion resistance enabling the use of bio fuels. In addition, the tailored surface topography of the thermal spray coatings help in supporting advantageous friction states and thereby show the benefit of reducing the oil consumption resulting in reduced emissions. The thermally sprayed coatings were applied using HVOF and HVSFS processes together with a specially designed spray gun trajectory in order to achieve a fast and cost efficient coating procedure. Several different coating materials, including novel nanostructured powders, have been investigated and compared to state-of-the-art cylinder liners. The performance of the coated cylinder liners regarding wear and corrosion resistance, friction coefficient and effects of the surface topography have been investigated in various test setups including engine tests.


2013 ◽  
Vol 711 ◽  
pp. 110-114
Author(s):  
Seung Jin Lee ◽  
Joon Sik Park ◽  
Jeong Min Kim ◽  
Ki Tae Kim

Typical as-cast microstructure of the MgZnRE-Zr alloys consists primarily of Mg matrix, MgZn and MgRE phases. Although the electrical conductivity was a slightly reduced by Ce-rich RE addition, the conductivity was remained high. Microhardness at room temperature and tensile strength at 200°C were clearly enhanced by the addition. Fluidity as mold filling ability was observed to increase significantly with the RE addition partly due to reduced grain size and solidification range, however the corrosion resistance predicted from polarization curves was little decreased.


1975 ◽  
Vol 11 (10) ◽  
pp. 915-917
Author(s):  
M. N. Gapchenko ◽  
Yu. D. Myshko ◽  
S. P. Petrov

Author(s):  
Hanna Karakurkchi ◽  
Mykola Sakhnenko ◽  
Irina Yermolenko ◽  
Serhii Indykov ◽  
Natalia Horokhivska ◽  
...  

Technological approaches to the application of functional electrochemical coatings in civil and military technologies are analyzed. It is shown that the existing technical solutions are aimed at solving the problems of strengthening and protection of surfaces and detoxification of environments from pollutants of natural and man-made origin. Electrochemical coatings based on the iron triad, doped with refractory metals, increase corrosion resistance, microhardness and wear resistance of surfaces. Doped with transition metals heteroxide coatings, which are synthesized by the method of plasma electrolytic oxidation on aluminum and titanium alloys have catalytic properties to neutralize toxic substances in the gas and liquid phases. Peculiarities of electrochemical formation of functional coatings on construction materials of different types are investigated. It is shown that cathodic deposition by direct and pulsed current on low-carbon steel and gray cast iron forms uniform ternary coatings of Fe-Mo-W and composite systems of Fe-Co-Mo (Fe-Co-W), which have increased corrosion resistance and mechanical properties compared to base metal material. The obtained thin-layer coatings are recommended for the restoration and strengthening of worn surfaces, in particular in the technology of repair of weapons and military equipment. It was found that plasma-electrolyte treatment of piston silumin in alkaline solutions based on diphosphates synthesized heteroxide systems that are active in reducing the number of toxic emissions of internal star engines and reducing hourly fuel consumption. It is shown that nanocomposite coatings on titanium show photocatalytic activity on the destruction of model pollutants. The obtained materials have a set of enhanced functional properties and are promising for use in industrial and repair production, including the security and defense sector.


Author(s):  
B. V. Farmakovsky ◽  
N. A. Sokolova ◽  
T. I. Bobkova

The paper describes an alloy with a content of 20–26% Co, 17.4–21.1% Cr, 2.6–4.9% Si, 3–5% Re, 4–6% Zr, 0.2–0,6% Ce, 0.1–0.5% La, 0.3–0.7%Y, 2–4% Al. The cobalt-based alloy is applied as protective coating on components of precision engineering with adhesion 42–45 MPa, microhardness 3.6 GPa, corrosion resistance class 1, within the range of operating temperatures from –60 to 550°С.


Materials ◽  
2020 ◽  
Vol 13 (15) ◽  
pp. 3257 ◽  
Author(s):  
Justyna Bącela ◽  
Magdalena Beata Łabowska ◽  
Jerzy Detyna ◽  
Anna Zięty ◽  
Izabela Michalak

In this literature review, the current state-of-art of coatings for orthodontic archwires’ increasing antimicrobial and relevant mechanical properties, such as surface topography, friction or corrosion resistance, has been presented. There is a growing request for orthodontic appliances, therefore, most researchers focus on innovative functional coatings to cover orthodontic archwires and brackets. Orthodontic appliances are exposed to the unfavorable oral cavity environment, consisting of saliva flow, food, temperature and appliance force. As a consequence, friction or biocorrosion processes may occur. This can affect the functionality of the orthodontic elements, causing changes in their microstructure, surface topography and mechanical properties. Furthermore, the material which the orthodontic archwire is made from is of particular importance in terms of the possible corrosion resistance. This is especially important for patients who are hypersensitive to metals, for example, nickel, which causes allergic reactions. In the literature, there are some studies, carried out in vitro and in vivo, mostly examining the antibacterial, antiadherent, mechanical and roughness properties of functional coatings. They are clinically acceptable but still some properties have to be studied and be developed for better results. In this paper the influence of additives such as nanoparticles of silver and nitrogen-doped TiO2 applied on orthodontic brackets by different methods on the antimicrobial properties was analyzed. Future improvement of coating techniques as well as modification of the archwire composition can reduce the release of nickel ions and eliminate friction and bacterial adhesion problems, thus accelerating treatment time.


Author(s):  
T. I. Bobkova ◽  
A. F. Vasiliev ◽  
E. A. Samodelkin ◽  
B. V. Farmakovsky

This article explores the characteristic and particular features of manufacturing nanostructured composite coatings with high microhardness from agglomerated powders of Kh20N80-WC system manufactured by high-speed mechanosynthesis. The properties of the functional coatings deposited by both supersonic cold gas-dynamic and microplasma spraying are studied.


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