The Wear Resistance of the Nanocomposite Coatings Obtained by the Cumulative- Detonation Device

Nanocomposite coatings based on Ti, O, C and H were deposited on aluminium samples by using the cumulative-detonation equipment. The nanocomposite coatings were examined by scanning electron microscopy (SEM), transmission electron microscopy (TEM) with diffraction, X-ray phase analysis, hardness measurements and tribotests. It was established that the wear of nanocomposite coatings based on Ti, O, C and H less than to the wear of material of the substrate. For the nanocomposite coating which were formed from the hydrogenated titanium powder was recorded the lowest wear and coefficient of friction. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3515

Structure and Properties of Nanocomposite Coatings Based on Titanium, Oxygen, Carbon and Hydrogen Obtained by the Cumulative-Detonation Device

Nanocomposite coatings based on Ti, O, C and H thickness of 70 – 200 microns with hardness of 1015 250 HV0.05 and porosity 2 – 5% were deposited on aluminium samples by using the cumulativedetonation equipment. The nanocomposite coatings were examined by scanning electron microscopy (SEM), transmission electron microscopy (TEM) with diffraction, X-ray phase analysis, hardness measurements. It is shown that the area of the coating that adjoins to the substrate contains a transition layer of intermetallic TiAl and the nanocomposite coatings based on Ti, O, C and H are characterized by the presence of titanium nanocrystalline grains with face-centered close-packed lattice, amorphous phases and nanoamorphous oxide of titanium. It was found that the main phases of the composite coatings are Ti, TiO, rutile, anatase, Ti2O3. In the composite coatings formed from the hydrogenated powder was recorded the presence of -TiH phase and TiH2. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3488

Structure and the Physico-Mechanical Properties of the Ceramic Coatings Obtained by the Cumulative -Detonation Device

Dense, with good adhesion to the substrate, hard, wear-resistant coatings from the powder of Al2O3 were obtained on the surface of the steel (STE255) by using the cumulative-detonation device. The results of investigations of the structure and physico-mechanical properties of the coatings by using scanning, optical microscopy, X-ray phase analysis, microhardness and tribological tests are presented. It was found that optimization of plasma spraying to helps reduce the porosity of coatings of Al2O3 less than 1 % and to increase the hardness of them to 1250 HV0.3. The tribological investigations have shown that the coatings of Al2O3 significantly increase the wear resistance of the sample STE255 and provide a low ability to wear out the coating. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3546

Properties of Nanoscale Carbon Coatings Obtained by the Pulsed Vacuum-Arc Method on Silicon

The complex of properties including the structure, adhesive strength, internal stresses, tribological properties, microhardness and crack-resistance of nanoscale carbon coatings obtained by the pulsed vacuum-arc method on single-crystal silicon substrates was investigated. Two types of samples of the carbon coating: type (i) formed at the normal location of the substrate relative to the geometric axis of the plasma flow (θ = 0°); type (ii) obtained at an angle θ = 70° were studied. The analysis of the experimental results showed, that the angle of plasma flow incidence relative to the substrate drastically affects the properties of carbon coatings. The structure, adhesion, internal stresses, wear resistance, crack resistance are interrelated and determined by the radiation-diffusion sealing during the process of carbon coating deposition from the carbon plasma flow. Nanoscale carbon coatings can significantly improve the strength and tribological properties of different tools, parts and products. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3530

Deposition of Alumina-titania Nanostructured Coating by a New Multi-chamber Gas-dynamic Accelerator

The aim of the study was to characterize alumina-titania (Al[2]O[3]:Ti wt ratio = 87:13) coatings were deposited by a new multi-chamber gas-dynamic accelerator on a grit blasted steel substrate. The aluminatitania coatings were characterized using scanning electron microscopy, X-ray diffraction techniques and Vickers hardness tester at a test load 200 g. The coating was well-adhered onto corrosion-resistant steel substrate. Obtained coatings possessed a unique microstructure consisting of fully melted regions with the microstructure similar to a typical thermal sprayed lamellar morphology and areas comprising unmelted or partially melted particles. The dense alumina-titania coatings with hardness of 657 ± 70 HV0.2 and porosity of less than 0.6% have been prepared by a new multi-chamber gas-dynamic accelerator

Deposition and Characterization of NiCoCrAlY Coatings by Multi-chamber Detonation Sprayer

In this study, multi-chamber detonation sprayer (MCDS) was applied for deposition of NiCoCrAlY powder coatings (60-65 mm thick) on nickel base superalloy JS6U (Russia). Powder RPCoCr27Al7Si3Y was used to deposit of a coating. The coating microstructures and phase compositions were characterized using SEM, OM and XRD techniques. Measurement of the microhardness of samples was done with a micro-hardness tester DM – 8B using a Vickers’s indenter with load on of 0.01 N. It was established that MCDS has provided the conditions for formation of a dense layer with porosity below 1% and microhardness of 1100 ± 250 HV0.1

Deposition and Characterization of NiCoCrAlY Coatings by Multi-chamber Detonation Sprayer

In this study, multi-chamber detonation sprayer (MCDS) was applied for deposition of NiCoCrAlY powder coatings (60-65 mm thick) on nickel base superalloy JS6U (Russia). Powder RPCoCr27Al7Si3Y was used to deposit of a coating. The coating microstructures and phase compositions were characterized using SEM, OM and XRD techniques. Measurement of the microhardness of samples was done with a micro-hardness tester DM – 8B using a Vickers’s indenter with load on of 0.01 N. It was established that MCDS has provided the conditions for formation of a dense layer with porosity below 1% and microhardness of 1100 ± 250 HV0.1

Improving the Wear Resistance of Thermally Sprayed Nanocomposite Cr3C2-25NiCr Coatings by Pulsed Plasma Treatment

In this study the surfaces of thermally sprayed nanocomposite Cr3C2-25NiCr coating have been treated by the pulsed plasma. The nanocomposite Cr3C2-25NiCr coating was deposited by a new multi-chamber gas-dynamic accelerator on grit blasted steel substrate. An automatic pulse-plasma device “Impulse-6” was employed to plasma treatment the surface of Cr3C2-25NiCr coating. The microstructure and wear resistance of the surface of the nanocomposite Cr3C2-NiCr coating before and after the pulsed plasma treatment (PPT) was studied in this paper. Wear tests were carried out using a computer controlled pin-on-disc type tribometer at 25 ºC. The specific wear rate of the nanocomposite Cr3C2-25NiCr coating after PPT is approximately four times less than that of the Cr3C2-25NiCr coating before PPT, indicating that the nanocomposite Cr3C2-25NiCr coating after PPT exhibits better wear resistance. Detailed analysis indicates that the enhanced wear resistance of the nanocomposite Cr3C2-25NiCr coating after PPT is mainly attributed to the formation of an oxide tribolayer and smoother surface, which result from the dense and amorphous microstructure of the coating