Study of Cavitation Erosion-Corrosion Resistance of Thermally Sprayed Ni-Based Coatings Prepared by HVAF Process

2020 ◽  
Vol 299 ◽  
pp. 893-901
Author(s):  
Hussam L. Alwan ◽  
Yury S. Korobov ◽  
N.N. Soboleva ◽  
N.V. Lezhnin ◽  
A.V. Makarov ◽  
...  
Keyword(s):  
Cavitation Erosion ◽  
Thermal Spraying ◽  
Superior Performance ◽  
Material Loss ◽  
Coating Materials ◽  
Sem Micrographs ◽  
Coating Surface ◽  
Erosion Corrosion ◽  
Before And After ◽  
Nicrbsi Coating

In this study, two Ni-based coating materials, namely NiCrMoNb and NiCrBSi, have been applied using High Velocity Air Fuel (HVAF) thermal spraying process. The performance of the coated surface in resistance to cavitation erosion-corrosion of both coating materials, has been evaluated using an ultrasonic vibratory method. The cumulative material loss and erosion rate curves of the two coatings have been discussed. Surface topography, microhardness, macroscopic images, and scanning electron microscope (SEM) micrographs were used to characterize the coatings before and after the cavitation test. The cavitation results showed that the NiCrMoNb coating surface has exhibited better performance than the NiCrBSi coating surface under the same test conditions. The total cumulative weight loss of the NiCrMoNb coating was about 1/3 that of the NiCrBSi coating. SEM micrographs of the eroded surfaces showed that the surface layer of the NiCrBSi coating was more damaged, compared to layer of the NiCrMoNb coating. Overall, the NiCrMoNb coating can be effectively used against the cavitation wear, due to its superior performance.

Cavitation Erosion-Corrosion Behavior of Fe-Cr Steel Induced by Ultrasonic Vibration

2020 ◽  
Vol 989 ◽  
pp. 312-317
Author(s):  
Hussam L. Alwan ◽  
Yury S. Korobov ◽  
N.N. Soboleva ◽  
D.A. Prokopyev
Keyword(s):  
Stainless Steel ◽  
Surface Topography ◽  
Cavitation Erosion ◽  
Martensitic Stainless Steel ◽  
Cavitation Resistance ◽  
Material Loss ◽  
Sem Micrographs ◽  
Test Conditions ◽  
Aisi 420 ◽  
Erosion Corrosion

A resistance of cavitation erosion-corrosion of the AISI 420 martensitic stainless steel was evaluated in this study. The cavitation resistance of this stainless steel has been examined using an ultrasonic vibratory method by applying water-voltage combination effect. The curves of cumulative material loss and erosion rate were attained and discussed. In addition, surface topography and scanning electron microscope (SEM) micrographs have been utilized to characterize the eroded surface after the cavitation test. The results have been compared with previously obtained results for the AISI 1040 steel. The cavitation results showed that the AISI 420 steel has exhibited the better resistance to cavitation comparing with the AISI 1040 steel under the similar test conditions. The total cumulative material loss of the AISI 420 was approximately three times less than that of the AISI 1040. Surface topography and SEM micrographs showed that the severity of damage of the AISI 1040 was found to be a higher compared to that of the AISI 420 steel.

Cavitation Erosion Resistant Coatings Produced by Thermal Spraying and by Weld Cladding

1998 ◽  
Author(s):  
H. Kreye ◽  
R. Schwetzke ◽  
A. Buschinelli ◽  
L. Boccanera
Keyword(s):  
Stainless Steel ◽  
Arc Welding ◽  
Erosion Rate ◽  
Cavitation Erosion ◽  
Thermal Spraying ◽  
Welding Process ◽  
Pulsed Power ◽  
Before And After ◽  
Arc Welding Process ◽  
Weld Cladding

Abstract The cavitation erosion of various hardfacing coatings was investigated by using a vibratory cavitation apparatus according to ASTM G 32. Coatings of austenitic stainless steel containing 10 % cobalt were applied by arc welding. High velocity oxy-fuel spraying (HVOF) was employed to produce coatings of various kinds of cermets and metallic alloys. For each coating, the steady state erosion rate was determined and the effect of process parameters and alloy composition on the microstructure and erosion rate was investigated. The morphology and microstructure of the coatings before and after cavitation testing were analysed by metallographic methods in order to study the erosion mechanism. It is demonstrated that the high resistance to cavitation erosion of the cobalt-alloyed steel can even further increase when the fluxed core arc welding process and an improved pulsed power source are used to produce the coatings. The erosion resistance of the HVOF coatings, however, was limited by pores, microcracks and oxides and did not significantly exceed the level typical for bulk stainless steel 316 L.

scholarly journals Toprak İşleme Makinalarının Aktif Elemanlarında Yüzey Kaplama Uygulamaları

2020 ◽  
Vol 8 (sp1) ◽  
pp. 92-99
Author(s):  
Yaşar Serhat Saygılı ◽  
Bülent Çakmak
Keyword(s):  
Wear Resistance ◽  
Agricultural Sector ◽  
Thermal Spraying ◽  
Film Coating ◽  
Soil Tillage ◽  
Material Loss ◽  
Coating Materials ◽  
Coating Methods ◽  
Phase Coating ◽  
Phase Liquid

Tillage machines such as plow, cultivator, rotavator, and rototiller are widely used for this purpose. However, one of the major problems in working with tillage machines is the wear of active parts over time. Abrasion occurs differently in active parts of tillage machines and can cause the machines used to lose the functionality expected of them. It is preferred to cover the active parts with wear-resistant coating materials to reduce the level of wear to meet both agro technical demands and high tillage efficiency. The way of wear the active parts of the machines; it is abrasive wear caused by friction against solid materials in the soil (clods, stones, harder materials, etc.) and/or adhesive wear caused by soil moisture. Reducing the wear on the active parts with the coating process to be made will both prevent material loss caused by abrasion in the active part and increase the efficiency/effectiveness of the machine. Because of the limited number of studies on this subject in the agricultural sector shows that the subject is open to improvement. In this study, the use of new coating methods used in other production sectors (especially in mold manufacturing) for the last decade in coating the active parts of soil tillage machines and their effects on product performance and life by increasing wear resistance are compiled. Coating methods that can be adapted to the agricultural sector can be listed as; Gas Phase, Liquid Phase and Melted/Semi-Melted Phase. Among these, studies on Plasma Thermal Spraying (Molten / Semi-Molten Phase Coating Methods) and thin film coating (Vapor Phase Coating Methods) are prominent. On the other hand, it is predicted that the desired wear resistance can be further improved by applying different coating methods and combinations.

Sunlight exposure: the effects on the performance of paragliding fabric

2018 ◽  
Vol 69 (05) ◽  
pp. 381-389
Author(s):  
MENGÜÇ GAMZE SÜPÜREN ◽  
TEMEL EMRAH ◽  
BOZDOĞAN FARUK
Keyword(s):  
Mechanical Properties ◽  
Aging Process ◽  
Air Permeability ◽  
Sunlight Exposure ◽  
Test Results ◽  
Coating Materials ◽  
Strength Tests ◽  
Before And After ◽  
The Relationship ◽  
Dark Blue

This study was designed to explore the relationship between sunlight exposure and the mechanical properties of paragliding fabrics which have different colors, densities, yarn counts, and coating materials. This study exposed 5 different colors of paragliding fabrics (red, turquoise, dark blue, orange, and white) to intense sunlight for 150 hours during the summer from 9:00 a.m. to 3:00 p.m. for 5 days a week for 5 weeks. Before and after the UV radiation aging process, the air permeability, tensile strength, tear strength, and bursting strength tests were performed. Test results were also evaluated using statistical methods. According to the results, the fading of the turquoise fabric was found to be the highest among the studied fabrics. It was determined that there is a significant decrease in the mechanical properties of the fabrics after sunlight exposure. After aging, the fabrics become considerably weaker in the case of mechanical properties due to the degradation in both the dyestuff and macromolecular structure of the fiber

Deterioration of Local Mechanical Properties of HVOF-Sprayed Stellite 6 after Exposure to High-Temperature Corrosion

2015 ◽  
Vol 662 ◽  
pp. 115-118 ◽  
Author(s):  
Zdeněk Česánek ◽  
Jan Schubert ◽  
Šárka Houdková ◽  
Olga Bláhová ◽  
Michaela Prantnerová
Keyword(s):  
Mechanical Properties ◽  
High Temperature ◽  
High Temperature Corrosion ◽  
Corrosion Testing ◽  
Time Interval ◽  
Coating Properties ◽  
Operational Conditions ◽  
Stellite 6 ◽  
Coating Surface ◽  
Before And After

Coating properties determine its behavior in operation. The simulation of future operational conditions is therefore the best quality test. The evaluation during operation is usually not possible to perform, and the coatings are therefore frequently characterized by their physical or mechanical properties. This text deals with the high temperature corrosion of HVOF sprayed Stellite 6 coating and with changes of its local mechanical properties before and after the corrosion testing. High temperature corrosion is defined as a corrosion in the presence of molten salts. In this case, the mixture of salts in composition of 59% Na2(SO)4 with 34.5% KCl and 6.5% NaCl was used. Two exposure temperatures 525 °C and 575 °C were selected and the tests for both temperatures were performed in the time interval of 168h in the autoclave. The coating with salt mixture layer was analyzed using scanning electron microscopy and nanoindentation. The high temperature resistance of Stellite 6 coating was evaluated according to the changes in the coating surface and by the occurrence of individual phases formed on the coating surface during the test. Generally, it can be said that the Stellite 6 alloys deposited by HVOF technology show selective oxidation under the salt film. This fact was also proved in this study. Furthermore, the nanoindentation measurements of Stellite 6 coating were performed before and after the corrosion testing. These measurements were used to evaluate the change of local mechanical coating properties.

Curing Time and Water Repellent Properties of Dammar-Titanium Dioxide Thin Film

2015 ◽  
Vol 1112 ◽  
pp. 359-362
Author(s):  
Aisyah Nor Hasnan ◽  
Azizah Hanom Ahmad
Keyword(s):  
Contact Angle ◽  
Titanium Dioxide ◽  
Contact Angle Measurement ◽  
Angle Measurement ◽  
Water Repellent ◽  
Coating System ◽  
Curing Time ◽  
Coating Surface ◽  
Natural Resin ◽  
Before And After

Dammar plant resin is a local natural resin that can be bled from Dipterocaupacea sp of tree. It can be found abundantly in Malaysia’s tropical forest especially in Sarawak. Dammar and Titanium Dioxide was mixed in a various wt% to produce Dammar-modified Titanium Dioxide coating system. The modified coating systems were then spin-coated onto Aluminium Q-panel as the substrate. Coated Q-panels were left to cure at room temperature. The curing time was evaluated using dust free stage. The addition of Titanium Dioxide into the coating system fastens the curing time taken for the coated Q-panel to be cure. It only took about 11-12 minutes to dry compared to the coating system before the addition of Titanium Dioxide where a quite long duration required, 32 minutes. Contact angle measurement was also carried out in order to determine the wettability of the coating system. The surface coated with dammar-modified titanium dioxide found to be hydrophobic where a quite large contact angle obtained for the sample with 3 wt% of Titanium Dioxide (PDT3). The water droplets actually rest on the coating surface without wetting the surface. Water absorption test was done to strengthen the contact angle results where coated substrate was soaked into distilled water for 24 hours and being weighed before and after soaking. The difference of before and after soaking weigh showed that the coating surface does not absorb that much water where only approximately 0.02% of water being absorbed by the coating system for 3 wt%. It proved that the coating systems applied are hydrophobic.

scholarly journals Effects of Ambient Conditions on the Dielectric Properties of Thermally Sprayed Ceramic Coating

2018 ◽  
Author(s):  
M Niittymäki ◽  
B. Rotthier ◽  
K. Lahti ◽  
T. Suhonen ◽  
J Metsäjoki
Keyword(s):  
Dielectric Properties ◽  
Dielectric Breakdown ◽  
Breakdown Strength ◽  
Thermal Spraying ◽  
Ceramic Coatings ◽  
Alumina Coating ◽  
Ambient Conditions ◽  
Coating Materials ◽  
Sprayed Coating ◽  
Thermally Sprayed

<p>Thermal spraying techniques are used to manufacture insulating coatings especially for demanding applications like fuel cells where normal insulating materials cannot be used. In electrical insulation applications, the mostly used coating materials are aluminum oxide (Al2O3), magnesium oxide (MgO) and magnesium aluminate (MgAl2O4). Dielectric properties of thermally sprayed ceramic coatings are strongly affected by ambient conditions, and in addition to this they are not well documented in the literature. In this paper the effects of environmental conditions on certain dielectric properties of a thermally sprayed coating are studied. DC resistivity as well as permittivity and losses at different frequencies at relative humidities of 20 % and 45 % at temperature of 20 °C, 40 °C and 60 °C will be reported in the paper for Al2O3 samples sprayed using HVOF (High Velocity Oxygen Fuel) technique. DC dielectric breakdown strength is also studied for the HVOF alumina coating at temperature of 20 °C and relative humidity of 20 %. Effects of ambient conditions and coating material composition are also analyzed.</p>

scholarly journals Cavitation Erosion and Sliding Wear of MCrAlY and NiCrMo Coatings Deposited by HVOF Thermal Spraying

2020 ◽  
Vol 20 (2) ◽  
pp. 26-38 ◽  
Author(s):  
M. Szala ◽  
M. Walczak ◽  
L. Łatka ◽  
K. Gancarczyk ◽  
D. Özkan
Keyword(s):  
Wear Resistance ◽  
Sliding Wear ◽  
Cavitation Erosion ◽  
Erosion Resistance ◽  
Nickel Content ◽  
Thermal Spraying ◽  
Point Of View ◽  
Engineering Practice ◽  
Hvof Thermal Spraying ◽  
Cavitation Erosion Resistance

AbstractThe investigation into wear resistance is an up-to-date problem from the point of view of both scientific and engineering practice. In this study, HVOF coatings such as MCrAlY (CoNiCrAlY and NiCoCrAlY) and NiCrMo were deposited on AISI 310 (X15CrNi25-20) stainless steel substrates. The microstructural properties and surface morphology of the as-sprayed coatings were examined. Cavitation erosion tests were conducted using the vibratory method in accordance with the ASTM G32 standard. Sliding wear was examined with the use of a ball-on-disc tribometer, and friction coefficients were measured. The sliding and cavitation wear mechanisms were identified with the SEM-EDS method. In comparison to the NiCrMo coating, the MCrAlY coatings have lower wear resistance. The cavitation erosion resistance of the as-sprayed M(Co,Ni)CrAlY coatings is almost two times lower than that of the as-sprayed NiCrMoFeCo deposit. Moreover, the sliding wear resistance increases with increasing the nickel content as follows: CoNiCrAlY < NiCoCrAlY < NiCrMoFeCo. The mean friction coefficient of CoNiCrAlY coating equals of 0.873, which almost 50% exceed those reported for coating NiCrMoFeCo of 0.573. The as-sprayed NiCrMoFeCo coating presents superior sliding wear and cavitation erosion resistance to the as-sprayed MCrAlY (CoNiCrAlY and NiCoCrAlY) coatings.

A brief review on the erosion-corrosion behavior of engineering materials

2018 ◽  
Vol 36 (5) ◽  
pp. 435-447 ◽  
Author(s):  
Roshan Kuruvila ◽  
S. Thirumalai Kumaran ◽  
M. Adam Khan ◽  
M. Uthayakumar
Keyword(s):  
Adverse Effects ◽  
Industrial Process ◽  
Industrial Applications ◽  
Appropriate Technology ◽  
Material Loss ◽  
Adverse Conditions ◽  
Wide Range ◽  
Erosion Corrosion ◽  
The Cost ◽  
Selection Of

AbstractThe efficiency of industry depends upon the working conditions of the equipment and components used in the industrial process. The biggest problems faced by the industries are the problems of erosion and corrosion. The harmful effects of corrosion will lead to material loss, which results from the degradation of the equipment. The degradation of the equipment will cause the breakdown of the plant; moreover, it is a threat to the safety of people, and also from the point of conservation, it can cause the exploitation of available resources. The cost of replacing equipment increases the expense, and it can also result in the temporary shutdown of the plant. The protection of surfaces from the adverse effects of corrosion and erosion-corrosion is a matter of great concern in most industrial applications. Advancements in technology provides a wide range of techniques to overcome adverse conditions. The selection of appropriate technology must be from the viewpoint of their interaction with the environment. This review paper addresses the adverse effects of erosion-corrosion in the present scenario.

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