Wyniki wyszukiwania - BazTech

1

Evaluation of the Possibility of Applying Thermal Barrier Coatings to AlSi7Mg Alloy Castings

Mróz Marek, Rąb Patryk

Archives of Foundry Engineering

|

2023

|

Vol. 23, iss. 3

104--109

EN

This paper analyses the possibility of applying thermal barrier coatings (TBCs) onto a substrate made of the AlSi7Mg alloy, intended for, among other things, internal combustion engine components. Engine components made of aluminum-silicon alloys, especially pistons and valve heads, are exposed to high temperature, pressure and thermal shock resulting from the combustion of the fuel-air mixture. These factors cause degradation of these components and can lead to damage. To minimize the risk of damage to engine components caused by heat stress, one way is to apply TBCs. Applying TBCs coatings to engine components improves their durability, increases power output and reduces fuel consumption. The research scope includes the application of an Al2O3-TiO3 coating via the APS (Air Plasma Spraying or Atmospheric Plasma Spraying) method onto a substrate of the AlSi7Mg alloy, analysis of the microstructure and chemical composition of the substrate and coating material, and assessment of the quality of the coating's bond with the AlSi7Mg alloy substrate using the scratch test method.

2

Influence of air plasma spraying process parameters on the thermal barrier coating deposited with micro- and nanopowders

Kubaszek Tadeusz, Góral Marek, Pędrak Paweł

Materials Science Poland

|

2022

|

Vol. 40, No. 3

80--92

EN

This study investigates the optimal conditions to deposit a thermal barrier coating using micro- and nanopowders in the air plasma spraying (APS) process. The influence of the APS process parameters on the thickness, porosity and hardness of the yttria-stabilized zirconia (YSZ; ZrO2 × 8Y2O3) coatings deposited with a single-electrode plasma gun was determined. The temperature and velocity of melted particles were determined by the DPV diagnostic system to decrease the number of experimental processes. The current and H2 flow rate were changed in this research. Metco-6700 YSZ micropowder has already been used in plasma spray physical vapor deposition. The results of this study suggest the possibility of using it for APS. The particles of this powder are characterized by high temperature (2,700°C–2,900°C) and high speed (>380 m/s). The highest thickness of the coating was obtained with 6 NLPM (normal liter per minute) H2flow and 800 A current. Difficulties were observed with the feeding of the powder particles at higher H2flow. The results showed that using APS, deposition of Metco-6609, a nanopowder normally used in suspension plasma spraying, is possible. In this research, this powder was fed using a carrier gas. The coatings were around 40 μm thick and had high porosity. The lowest porosity of the coating was obtained at a current of 600 A and H2 flow rate of 12 NLPM. In the coatings, unmelted spherical particles were also visible.

3

High temperature resistance of silicide-coated niobium

Szklarek Radosław, Tański Tomasz, Mendala Bogusław, Staszuk Marcin, Krzemiński Łukasz, Nuckowski Paweł, Sobczak Kamil

Bulletin of the Polish Academy of Sciences. Technical Sciences

|

2021

|

Vol. 69, nr 5

art. no. e137416

EN

In this paper, thermal oxidation resistance of silicide-coated niobium substrates was tested in a temperature range of 1300–1450°C using an HVOF burner. Pure niobium specimens were coated using the pack cementation CVD method. Three different silicide thickness coatings were deposited. Thermal oxidation resistance of the coated niobium substrates was tested in a temperature range of 1300–1450°C using an HVOF burner. All samples that passed the test showed their ability to stabilize the temperature over a time of 30 s during the thermal test. The rise time of substrate temperature takes about 10 s, following which it keeps constant values. In order to assess the quality of the Nb-Si coatings before and after the thermal test, light microscopy, scanning electron microscopy (SEM) along with chemical analysis (EDS), X-ray diffraction XRD and Vickers hardness test investigation were performed. Results confirmed the presence of substrate Nb compounds as well as Si addition. The oxygen compounds are a result of high temperature intense oxidizing environment that causes the generation of SiO phase in the form of quartz and cristobalite during thermal testing. Except for one specimen, all substrate surfaces pass the high temperature oxidation test with no damages.

4

Thermal barrier coating on I.C engine cylinder liner

Guruprakash V., Harivignesh N., Karthick G., Bose N.

Archives of Materials Science and Engineering

|

2016

|

Vol. 81, nr 1

37--41

EN

Purpose: In this research, Cerium Stabilized Zirconia is coated on the I.C engine cylinder liner using Plasma Spray Coating technique. The coating system has effects on the fuel consumption, the power and the combustion efficiency, pollution contents. Their performance characteristics and results are studied and tabulated. Design/methodology/approach: Thermal Barrier Coating (TBC) are used to achieve the reduced heat rejection in engine cylinders. It is known that the efficiency of internal combustion diesel engines changes 38-42%. It is about 60% of the fuel energy dismissed from combustion chamber. Findings: The results showed that, increasing the brake thermal efficiency and decreasing the specific fuel consumption for the light heat rejection engine with thermal coated cylinder liner compared to that of standard engine. There was increasing the NOx emission and O2 for thermal barrier coated engine. Practical implications: To save energy, combustion chamber component is coated with low thermal conduction materials. In this paper, we are giving idea to thermal barrier coating and ceramic materials which are used for making low heat released engines. It reduces the excessive heat transfer to the coolant and exhaust system, thus improves the mechanical and thermal efficiency

5

Nowe możliwości wytwarzania powłokowych barier cieplnych metodą natryskiwania plazmowego z zawiesin

Sokołowski P., Łatka L., Kozerski S.

Przegląd Spawalnictwa

|

2015

|

R. 87, nr 3

40--47

PL

Powłokowe bariery cieplne (Thermal. Barrier. Coatings) są zaawansowanymi systemami materiałowymi, których głównych zadaniem jest ochrona powierzchni metalicznych, np. w turbinach lotniczych, przed obciążeniami cieplnymi. Jednym z najważniejszych elementów tego układu jest zewnętrzna powłoka ceramiczna, która ze względu na małą przewodność cieplną oraz wysoką temperaturę topnienia umożliwia obniżenie profilu temperatury na przekroju elementów do wartości dopuszczalnych przez pozostałe materiały. Kluczowym zagadnieniem pozostaje możliwość wytwarzania omawianych powłok w sposób ekonomiczny oraz jednocześnie przy zachowaniu korzystnej struktury powłok gwarantującej zachowanie odpowiednich właściwości użytkowych. W badaniach przeprowadzono złożony plan eksperymentu natryskiwania powłok z uwzględnieniem różnych zmiennych w procesie: (i) prędkości liniowej palnika, (ii) odległości natryskiwania, (iii) zawartości fazy stałej w zawiesinie oraz (iv) sposobu przygotowania podłoża. W procesie natryskiwania użyto zawiesin na bazie dwóch różnych proszków tlenku cyrkonu: częściowo, oraz w pełni, stabilizowanego tlenkiem itru; oba są obecnie powszechnie stosowane w przemyśle. Na podstawie przeprowadzonych badań ich mikrostruktury dokonano oceny, czy metoda natryskiwania plazmowego z zawiesin, w perspektywie kolejnych lat, może stanowić alternatywę dla obecnie używanych metod do wytwarzanie powłokowych barier cieplnych.

EN

Thermal Barrier Coatings are advanced multi-material systems whose main goal is to protect metallic surfaces against thermal loads, like for example blades in gas turbines. One of the most important elements of TBC system is the ceramic top layer. Due to the low thermal conductivity and a high melting point it allows reducing the temperature profile measured on the cross-section of the element below the limit values for all used materials. The key issue is the ability to produce coatings in an economical way and maintaining a microstructure of coatings guaranteeing the preservation of proper properties at the same time. In the presented studies the complex spray process was conducted. Design of spray experiment was made taking into account the different variables in the process: (i) the linear speed of the torch, (ii) spraying distance, (iii) a solid content in the suspension, and (iv) way of preparing a substrate topography. Two different yttria stabilized zirconia powders were used to prepare suspensions: partially and fully stabilized respectively. These powders are now widely used in the industrial applications. Based on the microstructural studies an assessment was carried out if the Suspension Plasma Spraying can be an alternative method for the production of thermal barrier coatings to the processes applied currently.

6

Cohesion and Adhesion Interlayer of the Thermal Barrier Coatings Made of Cobalt Alloy MAR-M509

Opiekun Z. A., Trytek A.

Archives of Foundry Engineering

|

2014

|

Vol. 14, iss. 1 spec.

159--164

EN

The manuscript presents microstructure, geometrical product specification and results of scratch tests performed on the interlayer of thermal barrier coating (TBC) with Rockwell’s intender. The TBC was provided by depositing two layers; metallic interlayer and external ceramic layer onto a plate coating made of cobalt alloy MAR-M509 in plasma spraying process. The surface of the casting was sandblasted with Al2O3 powder in an air stream before the TBC was introduced. Scratches were made along the cross-section from a mould material (MAR-M509) through metallic interlayer and external ceramic layer in the TBC. Friction force, friction factor and acoustic emission were recorded during the test. It has been proved that metallic interlayer in the TBC of ca. 200 μm thickness forms tough coating without pores with good cohesion values and very good adhesion values to the mould.

7

Wybrane właściwości powłok TBC wytwarzanych metodą Triplex Pro 200 z otworami wycinanymi laserem

Sosnowy P., Swadźba L., Jurczak M., Witala B., Supernak W.

Inżynieria Materiałowa

|

2013

|

Vol. 34, nr 5

542--546

PL

W artykule przedstawiono badania nad wdrożeniem powłokowej bariery cieplnej tlenku cyrkonu stabilizowanego tlenkiem itru typu 8YSZ oraz powłoki międzywarstwy NiCoCrAlY otrzymane z zastosowaniem palnika trójelektrodowego Triplex Pro 200. Przedstawiono wyniki z badania materiałów powłokowych otrzymane podczas realizacji procesu natryskiwania. Próbki z nałożonymi powłokami poddano badaniom mikroskopowym w celu oceny mikrostruktury oraz przeprowadzono sprawdzenie siły wiązania dla otrzymanych powłok. Przedstawiono wyniki otrzymane z pomiarów za pomocą kamery termowizyjnej Accuraspray g3 prędkości i temperatury cząsteczek materiału podczas procesu natryskiwania powłok. W dalszej części artykułu, przedstawiono obrazy mikrostruktury powłok po procesie drążenia otworów metodą wycinania za pomocą lasera YAG. Zakres badań obejmował próby utleniania wysokotemperaturowego statycznego i cyklicznego w temperaturze 1100°C, badanie odporności korozyjnej w środowisku związków siarki w temperaturze 900°C, badanie odporności na cykliczne utlenianie i korozję wysokotemperaturową w temperaturze 1100°C (test burner rig).

EN

This paper will present the study on the implementation of a thermal barrier coating of zirconia stabilized with 8YSZ type yttrium oxide with NiCo- CrAlY interlayer obtained using three electrodes torch Triplex Pro 200. The results ofstudies ofcoating materials obtained during the process of spraying the sample imposed coatings were tested and the bonding strength test was performed for the obtained coatings. In addition, presented results obtained during the velocity and temperature of the coating material particles during spray coating using a thermal imaging camera Accuraspray g3. The remainder ofthe article presents the images coating microstructures with holes after cutting process using a YAG laser. The scope of the research includes tests of static and cyclic oxidation at high temperature of 1100°C, the study of corrosion resistance in sulphur compounds environment at 900°C, the test of cyclic resistance to high temperature oxidation and corrosion at 1100°C (burner rig test).

8

Mechanical Properties of Two Layers Thermal Barrier Coating Deposited on a Plate Made of Cobalt Alloy MAR-M509

Opiekun Z. A.

Archives of Foundry Engineering

|

2013

|

Vol. 13, iss. 1 spec.

131--134

EN

The manuscript presents a microstructure and mechanical properties of two layers of thermal barrier coating (TBC) deposited on a plate made of cobalt alloy MAR-M509. Based on measurements of microhardness made with Berkovitz’s indenter using Nano Scratch-Tester CSM Instruments, it was stated that elastic (Ee) to total energy (Ec) parameters (MIT=Ee/Ec), γ phase, matrix of alloy MAR-M509 (MITγ), metallic interlayer (45%Ni – 22% Co – 17% Cr – 16% Al – 0,3% Y),(MITM) and ceramic layer (MITZrO2) there are proportion 0,29:0,22:0,50.

9

Mikrostruktura i twardość powłokowej bariery cieplnej na odlewie z żarowytrzymałego stopu na osnowie kobaltu

Opiekun Z., Pająk D.

Rudy i Metale Nieżelazne

|

2012

|

R. 57, nr 6

374-377

PL

W artykule przedstawiono mikrostrukturę i właściwości mechaniczne powłokowej bariery cieplnej (TBC) wykonanej z ZrO2 na odlewie płytki ze stopu kobaltu MAR-M509. Na podstawie pomiarów mikrotwardości wykonanych piramidką Berkovitz'a przy użyciu Nano Scratch - Testera, CSM Instruments stwierdzono, że mikrotwardość TBC jest około 18 % większa niż mikrotwardość fazy [gamma] (osnowy stopu MAR-M509).

EN

The manuscript presents a microstructure and mechanical properties of thermal barrier coating (TBC) made of ZrO2 and deposited on a plate coating made of cobalt alloy MAR-M509. Based on measurements of microhardness made with Berkovitz's indenter when Nano Scratch - Tester, CSM Instruments was used, it was stated that microhardness of TBC is about 18 % larger than microhardness of [gamma] phase (matrix of alloy MAR-M509).

10

Kaczmarek J.

Transactions of the Institute of Fluid-Flow Machinery

|

2010

|

nr 122

3-43

EN

In this paper one discusses the problem of modeling of thermal barrier coatings in an unified way. This approach takes into account both mechanics of materials responsible for behavior of the thermal barrier coatings and its production relying on preparation of material for deposition and the deposition itself. Two pillars of the unified description are considered. The first one is the notion of index of structure. The second one is created by criteria of design of properties of the thermal barrier coatings. It is suggested to apply the multiscale method of modeling for the behavior of material in deposited layer called collection of dynamical systems with dimensional reduction. This multiscale approach is viewed as appropriate theoretical environment for expression of design criteria of the layer. We mean by this the criteria related to mechanical resistance against damage and criteria for thermal properties. It is accentuated that the two-scale segment of multicale modeling composed of molecular dynamics and nanoscale modeling is of primary importance for the design tasks. Possibility of consideration of both mentioned methods of modeling follows from properties of the collection of dynamical system approach which allow us to treat molecular dynamics and continuum mechanics models within one theoretical scheme. Premises for design of production of thermal barrier coatings process are placed in the design of layer properties which could be next transformed into design of indexes of structure corresponding to various stages of the deposition.

11

Investigations into the degradation mechanism of thermal barrier applied in IC engine

Hejwowski T.

Journal of KONES

|

2009

|

Vol. 16, No. 3

129-134

EN

In the present paper the results of investigations into the degradation mechanizm of thermal barrier coating (TBC) applied in spark ignited and naturally aspirated diesel engines are presented. The TBC comprised 0.09 mm thick NiCrAlY bond coat and 0.36 mm thick Al2O3-40%TiO2 top coat. The coating was atmospheric plasma sprayed on piston heads, inlet and outlet valves and engine head. Top coating was heavily damaged in thermal fatigue tests and in exploitation test on spark ignited engine. The mechanism of damage was spalling of the outermost layer of ceramics. Porosity of the ceramic coating increased significantly which made the coating permeable to the products of combustion and thus facilitated corrosion attack on bond layer. Spalling of coating did not increase wear of piston rings and sleeves. X-ray diffraction studies proved high phase stability ofAl2O3-40%TiO2 top coat. Al2Or40%TiO2 APS sprayed coating cannot be considered the alternative top coat to currently used ZrO2-8%Y2O3in engine applications. Thermal barrier coating based on Al2O3-40%TiO2 can not be used for adiabatization of diesel or spark ignited engines. Al2O3-40%TiO2 based TBC can be used in less demanding applications.

12

Effect of thermal barrier coating on temperature and stress distribution in diesel engine

Hejwowski T., Dębski H.

Journal of KONES

|

2009

|

Vol. 16, No. 4

147-154

EN

The paper presents results of FEM investigations into the effect of thermal barrier coating (TBC) on stress and temperature distributions in the components of naturally aspirated diesel engine. Calculations were performed by means of Abaqus ver. 6.8-3 computer program. The considered coating was plasma sprayed double-layered TBC consisting 0.15 mm thick NiCrAl bond layer and 0.3 mm ZrO2-8%Y2O3 top coat. TBC reduced the maximum temperature of the cylinder head by 15K compared to uncoated metal head, increased temperature of the outlet channel by 10 K and reduced maximum temperatures in inlet and outlet valves by 2 and 1.2 K, respectively. Although maximum temperature of the pis ton head remained the same after deposition of the coating but the range of temperatures at the piston head was reduced by 23.8%. Application o f TBC considerably reduced stresses in acritical region of outlet valve- the interface of stellite hardfacing /valve. The highest thermal stresses in the TBC were in the bondcoat, which confirms the common localization of damages. Stress concentrations were also found in the metal part at the edges of TBC and at the edges of the recess machined in the piston head. The reduction of metal temperatures and thermal gradients in protected components should have some positive effect on the components' durability.

PL

W pracy przedstawiono rezultaty badań numerycznych wpływu powłoki typu bariery cieplnej (TBC) na rozkład temperatur i naprężeń w elementach wolnossącego silnika ZS. Obliczenia numeryczne zostały wykonane przy pomocy programu Abaqus wer. 6.8-3. Rozważano natryskaną plazmowo powlokę dwuwarstwową składającą się z warstwy podkładowej o gr. 0,15 mm i warstwy ceramicznej ZrO2-8%Y2O3 o grubości 0,3 mm. TBC obniżyła maksymalną temperaturę głowicy silnika o 15 K w porównaniu do głowicy nie pokrytej powłoką oraz obniżyła maksymalne temperatury zaworów wylotowego i dolotowego o 2 K i 1,2 K, odpowiednio. Wprawdzie maksymalna temperatura tłoka pozostała stała ale obniżył się o 23,8% zakres temperatur na powierzchni tłoka. Zastosowanie powłoki znacznie obniżyło wartość naprężeń w krytycznym miejscu zaworu wylotowego- granicy podłoża i warstwy napawanej stellitem Najwyższa wartość naprężeń TBC występowała w warstwie podkładowej co potwierdziło częstą lokalizację pęknięć. Znaleziono również koncentracje naprężeń na krawędzi TBC i krawędzi wybrania w denku tłoka. Obniżenie temperatur metalu i gradientów temperatur w pokrytych elementach powinno wydłużyć trwałość elementów.

13

Thermal barrier coatings : characteristics of microstructure and properties, generation and directions of development of bond

Moskal G.

Journal of Achievements in Materials and Manufacturing Engineering

|

2009

|

Vol. 37, nr 2

323-331

EN

Purpose: The goal of the paper is to present the review of characterisation of microstructure, properties as well as technology of receiving the heat resistance layers used as bond coats in thermal barrier coatings. Design/methodology/approach: General structure characterisation of the final influence of individual TBC`s sublayers was described. Especially the detailed characterisation of bond coats such as MeCrAlY and aluminides diffusion coatings was showed (used for EB-PVD obtained TBC`s). Findings: The influence of modification of chemical composition was described on microstructure and property of bond coats as well. It defines reactive elements such as Hf and the noble metals - Pt influence on increasing of heat resistance of bond coats, and, as a consequence, the growth of durability of coating thermal barriers. Different methods of modification of basic layers, for example the additional aluminizing process of MCrAlY coating was described as well. Practical implications: Additionally, the other types of bond coats were characterised, typically used for energy conversion systems and in case of Diesel engines and especially bond coats for titanium and titanium aluminides alloys. Originality/value: In the last part of the paper, new concepts such as „smart coatings” and diffusion barriers were shown.

14

Effect of the microstructure of EB-PVD thermal barrier coatings on the thermal conductivity and the methods to reduce the thermal conductivity

Altun O., Boke Y. E.

Archives of Materials Science

|

2008

|

Vol. 29, nr 1-2

7-15

EN

Nowadays, the selection of the materials for usage aim is getting important because of the new high technologic developments. Especially for the parts operating at high temperatures, the materials which have low thermal conductivity and high mechanical resistance are preferred. Thermal Barrier Coatings (TBCs) are used in aerospace, diesel engine and power plant technologies due to porous structures and low thermal conductivity. Generally these coatings are applied by two methods, Electron Beam-Plasma Vapor Deposition (EB-PVD) and Atmospheric Plasma Spray (APS). EBPVD method provides the advantages of superior strain and thermal shock tolerant due to its columnar microsturucture. However this columnar structure increases the thermal conductivity of the coating, so this is an undesired property with regard to heat transfer. In this study, the effect of microstructure of the coating to the thermal conductivity of EB-PVD TBCs and the methods to reduce the thermal conductivity of these coatings have been investigated.

15

Measurement of residual stress in plasma-sprayed TBC with a gradient of porosity and chemical composition

Moskal G., Swadźba L., Rzychoń T.

Journal of Achievements in Materials and Manufacturing Engineering

|

2007

|

Vol. 23, nr 2

31-34

EN

Purpose: The purpose of the research was identification of the residual stress in the top coat of different type of thermal barrier coating with gradient of chemical composition and gradient of porosity. Design/methodology/approach: The APS technique was used to deposition of gradient coating. As a bond coat the NiCrAlY overlay coating was applied. Top-coat consist in the case of gradient of porosity - YSZ with different thickness and porosity and in the case of chemical composition gradient YSZ with AMDRY 365-2 powder. The research allowed the identification of qualitative and quantitative phase constitution of top coat and residual stress measurement by sin square Psi method form surface of coatings. Findings: It was found that the dominant phase in all the top coats was tetragonal zirconia with minor addition of monoclinic type of ZrO2 and in the case of residual stress the tensile conditions was observed in the case of gradient porosity and compressive stresses in the case of chemical gradient. Research limitations/implications: Characterization of stress level in gradient TBC's give possibility description of degradation mechanism of barrier coating. Practical implications: The results obtained allow the determination of the degree of life-time lost of the TBC system used as protection for creep resistant alloys. Originality/value: The results obtained are valuable contribution to the development of new type of TBC. They enable the identification of the degradation mechanisms in YSZ / MCrAlY / substrate system.

16

Advanced materials and protective coatings in aero-engines application

Hetmańczyk M., Swadźba L., Mendala B.

Journal of Achievements in Materials and Manufacturing Engineering

|

2007

|

Vol. 24, nr 1

372-381

EN

Purpose: The following article demonstrates the characteristics of the materials applied as parts of aircraft engine turbines and the stationary gas turbines. The principal technologies for manufacturing the heat resistant coatings and the erosion and corrosion resistant coatings were characterized. Sample applications for the aforementioned coatings are presented: on turbine blades, compressor blades and on parts of combustion chambers of aircraft engines. Design/methodology/approach: The nickel-based alloys were characterized. The following methods of depositing diffusion aluminide coatings were described: pack cementation, out of pack and CVD (chemical vapour deposition). The properties of thermal barrier coatings obtained by thermal spraying and physical vapour deposition (PVD) were presented. Findings: : The structures of aluminide and platinum modified aluminide coatings, which displayed higher heat resistance during the cyclic oxidation test, were presented. The structure of TBC coatings was described as well. During aircraft engine tests, the compressor blades with multilayer type Cr/CrN coatings exhibited higher wear resistance than the coatings covered with Ti/TiN. Research limitations/implications: The aluminide coatings were deposited on nickel-based superalloys, which are typically used to manufacture turbine blades for aircraft engines. The multilayer nitride coatings were produced by Arc-PVD method. Practical implications: All the described technologies and coatings find applications on parts of aircraft engines. Originality/value: The presented advanced technologies of manufacturing protective coatings on the parts of aircraft engines were developed by the authors of the following study as parts of their planned scientific research, research projects, and purpose projects.

17

Aging effect for interfacial fracture toughness of thermal barrier coating

Kishimoto K., Arai M., Okajima Y.

Zeszyty Naukowe. Mechanika / Politechnika Opolska

|

2005

|

z. 82

13-20

EN

Thermal barrier coating (TBC) is being applied to blade and stator in a land-based gas turbine to protect these hot parts from a high-temperature gas environment. The interfacial cohesive strength of TBC coated components is diminished by a long-term experience under a high-temperature, because of forming a thermal oxidation at the coating interface or a microstructure in the ceramic coating layer being changed gradually. Consequently, it is quite important to understand how the interfacial strength of TBC changes with an exposed condition. This paper presents some experimental results for the interfacial fracture toughness of TBC coated material measured using the biaxial interfacial fracture test device developed by our group. A formation of the interfacial oxidation and an aspect of the interfacial fracture are related to change of the fracture toughness with an aging condition.

18

FEM analysis of functionally graded coating applied to diesel engine piston crown

Hejwowski T., Dębski H.

Eksploatacja i Niezawodność

|

2004

|

nr 1

30-34

EN

Functionally graded thermal barrier coating was analytically investigated by using Abwpis FEM code. Transient temperature and stress distributions in coatings applied to diesel engine piston crowns were calculated throughout the entire working cycle. Results of calculations were compared against data obtained for metal piston and classical duplex TBC.

19

Structure and properties of TBC coatings obtained on the nickel base superalloys by a thermal spraying method.

Swadźba L., Hetmańczyk M., Mendala B., Dudek S., Szala J.

Inżynieria Materiałowa

|

1998

|

R. XIX, nr 4

1061-1066

EN

Results of investigations on obtaining the thermal barrier coatings (TBC) and their properties have been presented in the article. Coatings were formed by a thermal spraying method using a A3000 system controlled by computer and with a robot. For spraying the following materials: ZrO2xY2O3 and MeCrAlY as an interlayer were used. The coating structure examinations were made. Powder morphology was determined by the scanning microscope method. Tests by the thermal shock method were conducted in the air atmosphere by heating the specimens to 1200 degrees centigrade for 15 min. and cooling to 250 degrees centigrade for 5 min. Hot corrosion resistance tests were conducted at 900 degrees centigrade in the Na2SO4 medium. Tests showed low resistance of TBC coatings to that type of corrosion. The TBC coatings were formed on the combustion chamber elements.