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Thermal barrier coatings (TBCs) are widely used in gas turbine engines because they allow higher operating temperatures due to their thermal insulation effect. The aim of this paper is to explain the effect of the substrate (base metal) on the performance of TBCs applied to various nickel‐based superalloys and stainless steels.

Specimens were prepared by applying atmospheric plasma spraying (APS). Six TBC‐coated samples were prepared. Three of the substrates were stainless steel and the rest were nickel‐based superalloys. Characterization effort included thermal exposure, microhardness testing, optical metallography and image analysis.

Microhardness test results showed that extended periods in high‐temperature environments affected the coating morphology, which was measured by changes in the microhardness values. At the end of the long periods in the furnace, microhardness values increased, which might be a sign that modulus of the coating increased. These changes in the microhardness might be due to the sintering effect and morphological changes that occurred in the coating. Effects of thermal exposure to the coatings were also visible in the micrographs in the form of fully open cracks. Development of larger cracks was life‐threatening for the ceramic coating.

It was shown for the first time that, in the above‐mentioned crack growth and spallation stages, stainless steel and superalloy substrates showed considerably different performances. Microhardness test results of coatings on different substrates were considerably dissimilar, which was a sign that the coating morphology was affected during thermal exposure.

This paper gives a bibliographical review of the finite element methods (FEMs) applied to the analysis of ceramics and glass materials. The bibliography at the end of the paper contains references to papers, conference proceedings and theses/dissertations on the subject that were published between 1977‐1998. The following topics are included: ceramics – material and mechanical properties in general, ceramic coatings and joining problems, ceramic composites, ferrites, piezoceramics, ceramic tools and machining, material processing simulations, fracture mechanics and damage, applications of ceramic/composites in engineering; glass – material and mechanical properties in general, glass fiber composites, material processing simulations, fracture mechanics and damage, and applications of glasses in engineering.

High temperature thermal shock causes the breakdown of Thermal Barrier Coating (TBC) systems. This paper focusing attention on the Zirconate TBC coating to study the thermo mechanical behavior such as wear and thermal shock test has been conducted inter metallic bond coat and Zirconate TBC to know the wear and thermal characteristics, and wear behavior has been studied on intermetallic bond coat using dry abrasion test and thermal characteristics studied on Zirconate TBC systems using thermal shock resistance test and finally the coatings characteristics before and after thermal cycling were evaluated.

Intumescent coatings are nowadays a dominant passive system used to protect structural materials in case of fire. Due to their reactive swelling behaviour, intumescent coatings are particularly complex materials to be modelled and predicted, which can be extremely useful especially for performance-based fire safety designs. In addition, many parameters influence their performance, and this challenges the definition and quantification of their material properties. Several approaches and models of various complexities are proposed in the literature, and they are reviewed and analysed in a critical literature review.

Analytical, finite-difference and finite-element methods for modelling intumescent coatings are compared, followed by the definition and quantification of the main physical, thermal, and optical properties of intumescent coatings: swelled thickness, thermal conductivity and resistance, density, specific heat capacity, and emissivity/absorptivity.

The study highlights the scarce consideration of key influencing factors on the material properties, and the tendency to simplify the problem into effective thermo-physical properties, such as effective thermal conductivity. As a conclusion, the literature review underlines the lack of homogenisation of modelling approaches and material properties, as well as the need for a universal modelling method that can generally simulate the performance of intumescent coatings, combine the large amount of published experimental data, and reliably produce fire-safe performance-based designs.

Due to their limited applicability, high complexity and little comparability, the presented literature review does not focus on analysing and comparing different multi-component models, constituted of many model-specific input parameters. On the contrary, the presented literature review compares various approaches, models and thermo-physical properties which primarily focusses on solving the heat transfer problem through swelling intumescent systems.

The presented literature review analyses and discusses the various modelling approaches to describe and predict the behaviour of swelling intumescent coatings as fire protection for structural materials. Due to the vast variety of available commercial products and potential testing conditions, these data are rarely compared and combined to achieve an overall understanding on the response of intumescent coatings as fire protection measure. The study highlights the lack of information and homogenisation of various modelling approaches, and it underlines the research needs about several aspects related to the intumescent coating behaviour modelling, also providing some useful suggestions for future studies.

The aim of the research is to increase piston and engine performance by using ceramic coated pistons instead of pistons which are manufactured from aluminum alloys and having a coated flame chamber.

Thermal torch and thermal shock tests were performed on the pistons and some specimens of 1.5 mm thick were prepared according to ASTM standards; both have the same material characteristics. In the present work, plasma spray technique was used for ceramic coating.

It was found that the ceramic coating, which, when performed properly, has compatible expansion coefficient with the aluminum alloy pistons, increases performance of pistons and engines.

Coatings were limited with one type of bonding and two ceramics, and coated parts were subjected to thermal torch and thermal shock tests.

For future work, instead of using other coating materials, stable yttria is used as the best coating material with optimum thermal resistance. By this process, working life of the machine parts can be extended and a number of economical advantages may also be obtained.

This paper fulfils the identified information and offers practical help to the industrial firms working with ceramic coatings and also to the academicians working on wear of materials.

Thermal barrier coatings (TBCs), which are used in high temperature applications of gas turbines, are damaged due to fuels and airborne minerals under working conditions. Stable zirconia coatings, which are usually used as topcoat materials in TBCs, are damaged by interacting at high temperatures with elements such as vanadium and sulfur from low quality fuels. The purpose of this paper is to see the failure mechanism of TBC systems after hot corrosion damages.

CoNiCrAlY metallic bond coatings of TBC samples were produced by cold gas dynamic spray method which is a new trend production method and stabilized zirconia ceramic top coating was produced by atmospheric plasma spray method. In total, 50% by weight of V₂O₅ and 50% Na₂SO₄ salt mixtures were placed on TBC samples and subjected to hot corrosion test at 1000°C.

Hot corrosion behaviors of TBC samples were examined by scanning electron microscopy, elemental mapping analysis, energy dispersive X-ray spectrometry analysis and X-ray diffraction analysis. TBC samples were damaged at the end of 12-h cycles.

The paper provides to understand the mechanism of hot corrosion of TBCs with cold sprayed metallic bond coat.

The purpose of this paper is to examine the transient heat conduction in a two-dimensional anisotropic substrate coated with a thin layer of thermal barrier coating (TBC). Nowadays, materials with anisotropic properties have been extensively applied in various engineering applications for enhanced strength. However, under an extreme operating environment of high temperature, the strength of the materials may largely decline. As a common practice in engineering, TBC are usually applied to thermally insulate the substrates so as to allow for higher operating temperature. This research provides engineers a numerical approach for properly designing the TBC to protect the anisotropic substrate.

For this investigation, a finite difference scheme using the domain mapping technique, transforming the anisotropic domain into isotropic one, is employed. The analysis considers three respective boundary conditions, namely Dirichelete condition, Neumann condition, and also forced convection, and studies the effect of various variables on the heat conduction in the coated system. Additionally, formulas for the steady-state temperature drop across the coating layer at the center are analytically derived. By comparing the numerical results with the analytical solutions, the veracity of the formulas is verified.

A few interesting phenomena are observed from the numerical results. First, the rotation of the substrate's principal axes affects the temperature on the TBC front surface in a more obvious manner for the Neumann condition than that for convection. Second, the temperature profile of the Dirichelete condition rises faster than the other cases, although all their profiles present a similar pattern. Third, the transient temperature drop across the TBC under the convection condition presents a complicated pattern, depending on the TBC thickness. Finally, the increase of TBC thickness under the Dirichelete condition may provide better insulation than the other cases. In this paper, approximate analytical formulations for the steady-state temperature drop across the TBC are also presented. Numerical results by the finite difference method indicate excellent agreements with the analytical solutions.

In the past, the finite element method (FEM) is usually applied for analyzing the heat conduction problem of TBC. However, one serious deficiency of applying the FEM to the TBC problem lies in the demand for a vast amount of elements (or cells) when the TBC thickness is far smaller than the substrate dimension. For ultra-thin coating, an enormous amount of elements are required that may lead to an extremely heavy computational burden. The paper presents an innovative finite difference approach that can be applied to analyze the heat conduction across the TBC coated on an anisotropic substrate. On the interface between the TBC and the substrate, a special heat equilibrium condition and the compatibility condition of identical temperature on the adjacent materials are used to propose three new models to predict the temperature drop across the TBC.

Ceramic materials and glasses have become important in modern industry as well as in the consumer environment. Heat resistant ceramics are used in the metal forming processes or as welding and brazing fixtures, etc. Ceramic materials are frequently used in industries where a wear and chemical resistance are required criteria (seals, liners, grinding wheels, machining tools, etc.). Electrical, magnetic and optical properties of ceramic materials are important in electrical and electronic industries where these materials are used as sensors and actuators, integrated circuits, piezoelectric transducers, ultrasonic devices, microwave devices, magnetic tapes, and in other applications. A significant amount of literature is available on the finite element modelling (FEM) of ceramics and glass. This paper gives a listing of these published papers and is a continuation of the author's bibliography entitled “Finite element modelling of ceramics and glass” and published in Engineering Computations, Vol. 16, 1999, pp. 510‐71 for the period 1977‐1998.

The form of the paper is a bibliography. Listed references have been retrieved from the author's database, MAKEBASE. Also Compendex has been checked. The period is 1998‐2004.

Provides a listing of 1,432 references. The following topics are included: ceramics – material and mechanical properties in general, ceramic coatings and joining problems, ceramic composites, piezoceramics, ceramic tools and machining, material processing simulations, fracture mechanics and damage, applications of ceramic/composites in engineering; glass – material and mechanical properties in general, glass fiber composites, material processing simulations, fracture mechanics and damage, and applications of glasses in engineering.

This paper makes it easy for professionals working with the numerical methods with applications to ceramics and glasses to be up‐to‐date in an effective way.

One of a series of papers presented at a Symposium on the Cost Effectiveness of Sprayed Metal Coatings, organised by the Association of Metal Sprayers.