Papers by Keyword: Ceramic Coating

Abstract: A simple test approach named relative method is developed for determining the thermal expansion coefficient of ceramic coatings. Although ceramic coatings are hardly separated from the substrates, it was evaluated in this work simply by need only the measured thermal expansion coefficient of coated samples and substrates. This novel method was demonstrated to be valid for rectangular beam samples of two types of coating configurations: sandwich coating and around coating. The feasibility of this test method was confirmed by experimental results of SiC coating.

Abstract: Industrial dust emission is a kind of pollution which might occur due to the green sand mold process in the foundry industry. This material is predominately composed by sand, clay, carbon and metallic oxides. The ceramic industry has already assumed the role of consumer of by-products generated by such industries, mainly by having similarity between the composition of by-products and raw material employed in the ceramic sector. In a preliminary study the dust from exhaustion was define as a thin material with a high content of non-plastic material and the presence of carbon, which can interfere with processing and properties of the final product. This study aims to show the effect of exhaustion powder addition in atomized clay in order to develop ceramic coating. The results of the effect of sintering temperature and the percentage of residue on properties such as apparent density, linear shrinkage, water absorption and open porosity are presented.

Abstract: Microscopic observation and testing were carried out on the structure & texture, bonding form and performances of different plasma-sprayed ceramic coatings on the wear surface of Cr12MoV dies by KYKY-2800B SEM. The result indicates that the bonding between the coating and the die matrix surface is mainly of mechanical form, the bonding strength of coating is higher than that of the matrix material, the coating has a low structural porosity and the hardness and friction performance of the die surface are somewhat improved. Compared with the original dies, not only their dimensional accuracy and quality standard are no lower but also their performance such as wear resistance and corrosion resistance are better, fully satisfying the requirements of die repair & remanufacture.

Abstract: With the consistent improvement of the laser power and energy, further enhancement of the laser resistant ability of the target board is becoming a more and more crucial task in high energy laser diagnostics and irradiation effect studies. Applications of ceramic materials in high energy laser damage were studied. An aluminum panel was coated with ZrO₂ ceramic for high power laser proof. Reflectivity and diffuse reflection characteristics of the coating were investigated at different wavelengths. Numerical simulation was conducted to analyze the thermal response of the coating under high power laser radiation. And, related experiments were carried out with high power fiber lasers. Irradiation experiments indicate that the ceramic layer helps to delay the heat conduction and reduce the peak temperature of the target board.

Abstract: Although elastic modulus of ceramic coatings at elevated temperature is difficult to measure, it was evaluated in this work simply by impulse excitation tests based on the relative method that need only the measured moduli of coated sample and substrate. This novel method was demonstrated to be valid not only for the single layer coating but also for multilayer coatings.

Abstract: Technology for surface protection in contact with seawater has been studied. It mainly focuses on the capability of superhydrophobicity characteristic. Currently, the application of superhydrophobicity in controlling corrosion problem in the marine environment is still new. The development of superhydrophobicity on the materials surface can be achieved by designing a specific texture pattern in micro-or nanometer scale for producing high roughness surface. This review paper is mainly on the laser technology for producing superhydrophobicity characteristic of materials surface. This technique offers the most control and precision over the produced geometry.

Abstract: Ceramic coating on the internal combustion engine has appeared as one of the great means that increase performance and efficiency of an engine. This paper presents a novel approach for the optimization and study of the effect of performance of ceramic coated internal combustion engine. In this paper, different parameters like engine load and engine speed are optimized with the consideration of various responses such as engine power output, volumetric efficiency, heat transfer rate to coolant and carbon monoxide (CO) emission. Experiments are carried out by varying the parameters of load and engine speed of ceramic coated internal combustion engine. Orthogonal array is taken to conduct the experiments with the load of 40 Nm, 120 Nm, 200 Nm and speed of 1200, 2000 and 2800 in rev/min. This method shows a good convergence with the experimental and optimum process parameters where maximum volumetric efficiency, minimum heat transfer rate and minimum CO emission are obtained by using the grey relational analysis method.

Abstract: Advanced ceramic coating technologies are commonly used as metal coatings for internal combustion engine components and aerospace application. The thermal barrier coatings are being applied to the engine components to increasing life and improve the performance of the engine. This experimental study is focused on advanced ceramic material of Zirconia stabilized with the yttrium oxide (Zirconia 80% wt and Yttia 20 % by weight) applied on the piston crown for analyzing the performance and emission characteristics of the diesel engine. By using ceramics coated piston crown, the brake thermal efficiency and specific fuel consumption were improved as compared to that of the piston without coating. Exhaust emission level of CO, UHC and NOx are also considerably reduced using advanced ceramic metal coating techniques.

Abstract: A relative study among various types of coating materials to develop wear resistance of stainless steel has been performed. Ceramic coatings with the thickness up to 250 μm were prepared by Atmospheric plasma spray technique on the stainless steel. Two different types of coating materials such that Yttria Stabilised Zirconia, Zirconia Ceria powder were used. The influence of Ceria powder on abrasive wear was determined. It was found that the addition of Ceria to Yttria Stabilised Zirconia in a sufficient amount helped in increasing its wear resistance compared to the wear behaviour of pure Yttria Stabilised Zirconia powder. Moreover, it was found that the lesser the surface roughness of the coating layer,.

Abstract: The plasma spraying Al₂O₃+13wt. %TiO₂ ceramic coating was coated with organic-inorganic hybrid emulsion. The hybrid emulsion prepared through co-hydrolysis and copolycondensation reactions of tetraethoxysilane (TEOS) and methyltriethoxysilane (MTES), and methylsilicone resin was added in the emulsion to improve the film-forming properties. The morphologies, chemical compositions and hydrophobicity of the resulting surfaces were analyzed by scanning electron microscopy (SEM), 3-dimensional stereoscopic microscope, energy dispersive X-ray detector (EDX), Fourier transfer infrared spectrometer (FT-IR) and water contact angle measurement. When the mole ratio of TEOS/MTES and the weight ratio of methylsilicone resin were 1:1 and 3.5wt. %, respectively, this surface displayed good film-forming properties. The contact angle was 130.24°, and the contact angle hysteresis was less than 10°.