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Ceramic Coatings (ceramic + coating)
Selected AbstractsChromium-Free Corrosion Resistance of Metals by Ceramic CoatingJOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 12 2001Satomi Ono Metal surfaces can be improved in terms of thermal, mechanical, and chemical properties by a ceramic coating. The chromium-free corrosion resistance of stainless steel was achieved using a chemical solution method. Precursor solutions were prepared from metal alkoxides and were deposited on stainless-steel surfaces by dip coating and heat-treating at temperatures <500°C. The stainless steel was coated by silica, zirconia, and titania single-layer coating films, and/or coated by silica/zirconia and silica/titania double-layer coating films. The corrosion resistance was improved remarkably by a submicrometer silica-based coating on the stainless steel. [source] Microstructural and Mechanical Investigations on Porcelain-Fused-to-Metal in Multilayer SystemADVANCED ENGINEERING MATERIALS, Issue 4 2010Adele Carradō Results on porcelain-fused-to-metal (PFM) technique of ceramic films for biomedical applications on metal substrate are reported. The coating of metallic implants with bio-ceramic films (glassy and opaque ceramic) was proposed to be a solution for combining the mechanical properties of the metallic material with the bioactive character of the ceramic layer, leading to a better integration of the entire implant. The aim of this paper is to determine a stress field distribution by a non-destructive method as high-energy synchrotron X-ray diffraction in energy dispersive in the metal and glass ceramic bulk as well as at metal,opaque ceramic interface in PFM three layers sample. Tensile stresses were found in palladium substrate and compressive state in glass ceramic coating. Moreover thermal stresses induced by PFM coating at the interfaces were calculated by analytical mathematical model, confirming that the stresses induced, due to the selection of the materials, are low. Finally, the micro-structural and chemical characteristics of glassy and opaque bio-ceramic coatings on palladium alloy substrate were investigated and no inter-diffusion area between metal and ceramic could be detected as well as non-homogeneity in the interface ceramic. [source] Cost-Efficient Metal,Ceramic Composites,Novel Foam-Preforms, Casting Processes and Characterisation,ADVANCED ENGINEERING MATERIALS, Issue 3 2010Gisela Standke Because of their dissatisfactory cost-performance ratio metal matrix composites (MMCs) are still not established in industry, although they show improved properties compared to pure metals in some application fields. The present paper describes the development of enhanced MMCs based on silicon carbide (SiC) foams made by the Schwartzwalder process. Therefore, foams with cell sizes of 30, 45 and 60,ppi based on pressure less sintered SiC (SSiC) were developed. They were coated with layers of coarse SiC particles, which form a rough strut surface. The ceramic content of the foams could be increased to values of 20,30,mass%. Additionally, foam preforms based on clay-bonded SiC (as they are known from molten metal infiltration) were tested. The preforms were infiltrated with aluminium alloys AlSi9Cu3 and AlSi7Mg0.6 and cast iron EN-GJSA-XNiCr35-5-2 and EN-GJL-250. For aluminium alloys high pressure die casting (HPC) as well as gravity casting was applied, whereas iron was only infiltrated by gravity casting. For HPC an excellent interlocking of metal and preform was observed because of the microporosity of the rough surface of the SSiC foam struts. By the use of gravity casting preform cells up to 45,ppi could be well infiltrated. Microporosity in the ceramic coating and the typical hollow struts of the foams did not show metal infiltration. Even by use of moderate ceramic volume fractions pressure-infiltrated aluminium matrix composites showed a high specific stiffness of up to E/,,=,42,GPa,cm3,g,1 compared to conventional Al or Mg alloys (E/,,=,25,27,GPa,cm3,g,1). Ceramic foam based MMCs produced by pressure less casting showed no advantages in mechanical properties compared to pure metals. Nevertheless it can be expected that they can provide improved wear resistance and lower thermal expansion coefficients. [source] Chromium-Free Corrosion Resistance of Metals by Ceramic CoatingJOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 12 2001Satomi Ono Metal surfaces can be improved in terms of thermal, mechanical, and chemical properties by a ceramic coating. The chromium-free corrosion resistance of stainless steel was achieved using a chemical solution method. Precursor solutions were prepared from metal alkoxides and were deposited on stainless-steel surfaces by dip coating and heat-treating at temperatures <500°C. The stainless steel was coated by silica, zirconia, and titania single-layer coating films, and/or coated by silica/zirconia and silica/titania double-layer coating films. The corrosion resistance was improved remarkably by a submicrometer silica-based coating on the stainless steel. [source] Characteristics of anodic coatings oxidized to different voltage on AZ91D Mg alloy by micro-arc oxidization techniqueMATERIALS AND CORROSION/WERKSTOFFE UND KORROSION, Issue 2 2005Y. Wang Abstract With increasing applied voltage, three types of anodic coatings, passive film, micro-spark ceramic coating and spark ceramic coating were made by micro-arc oxidization (MAO) technique on AZ91D magnesium alloy in alkali-silicate solution. The structure, composition characteristics and the electrochemical properties of coatings were also studied with SEM, XRD and EIS (electrochemical impedance spectroscopy) technique, respectively. It is found that the electrochemical properties are closely related to the structure and composition characteristics of the anodic coatings. At the same time, the characteristics of the three types of anodic coatings differ significantly, among them, the micro-spark ceramic coating, prepared in the voltage range of 170~220V exhibits compact, homogeneous structure and highest corrosion-resistance. [source] Influence of Al-Containing Interfacial Coatings on Carbon-Fiber/Bakelite Composite Thermal and Electrical Properties,ADVANCED ENGINEERING MATERIALS, Issue 5 2009Zeljko Pajkic Polymer-matrix (BakeliteŽ) composites were produced with coated short carbon fibers as a filler material and characterized in terms of their thermal, electrical, and mechanical properties. The influence of thin, Al-containing ceramic coatings on the composite material's macroscopic properties is discussed, as the composites with interfacial coatings show improvements in some properties, as compared to the ones with uncoated fibers. [source] Creep Behavior of Plasma-Sprayed Zirconia Thermal Barrier CoatingsJOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 9 2007Reza Soltani Thermally sprayed ceramic coatings deposited from nanostructured feedstock powder have often demonstrated improved properties relative to coatings produced from conventional powders. This type of coating has been reported to exhibit better wear resistance and higher adhesion strength compared with conventional deposits. Powder consisting of hollow spherical particles has been reported to produce coating with lower unmelted particles and lower thermal conductivity. In this study, the thermo-mechanical properties of plasma-sprayed yttria-stabilized zirconia coatings deposited using each of these types of powder were investigated. Creep strain and creep rate were measured using free-standing thick coatings loaded in a four-point bend configuration at temperatures ranging from 800° to 1200°C in air under a range of loads. The creep exponent and activation energy were determined. [source] Silicon Carbide Films by Laser Pyrolysis of PolycarbosilaneJOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 1 2001Paolo Colombo Thin films of polycarbosilane were deposited on Si and SiO2 substrates. Instead of conventional oven annealing (high temperatures, inert atmosphere), laser pyrolysis was used to achieve the polymer-to-ceramic conversion. In some conditions, especially when laser radiation absorption was enhanced by depositing a carbon layer on the surface of as-deposited films or by embedding graphite particles, this processing method yielded SiC ceramic coatings, without damaging the substrate. Processing in air or low vacuum did not result in oxidized coatings, contrary to what happens for oven pyrolysis. Laser-converted films were similar to oven-heated films processed at 1000° to 1200°C. [source] Rapid reduction of Legionella pneumophila on stainless steel with zeolite coatings containing silver and zinc ionsLETTERS IN APPLIED MICROBIOLOGY, Issue 2 2003P. Rusin Abstract Aims: To determine the rate of reduction of Legionella pneumophila by stainless steel surfaces with zeolite ceramic coatings containing 2ˇ5% (w/w) silver (Ag) and 14% zinc (Zn) ions. Methods and Results: Stainless steel pans with and without Ag/Zn coatings were inoculated with solutions of Leg. pneumophila ATCC 33155 and incubated at 37 °C. Survival was monitored using the spread-plate technique on selective buffered charcoal yeast extract agar. Significant reductions of Leg. pneumophila were effected by the Ag/Zn zeolite coatings within 2 h of exposure. Conclusions, Significance and Impact of the Study: Zeolite ceramic Ag/Zn coatings impart significant anti- Legionella properties to stainless steel surfaces. Coated stainless steel could be used in the manufacture of air ducts, condensation pans and intake and exhaust vents. These products have the potential to reduce numbers of Legionella in air-handling systems. [source] INCISED SLIPWARE PRODUCTION AT CASTELFIORENTINO (FLORENCE): THE ,VIA BERTINI' SITE (15TH,17TH CENTURIES)*ARCHAEOMETRY, Issue 5 2008N. BRIANESE This study deals with the physical,chemical and mineralogical,petrographic investigations (OM, SEM,EDS, EPMA, ICP, XRpD, Mössbauer and IR) conducted on first- and second-firing wasters belonging to two types of incised slipware (sgraffito), manufactured at Castelfiorentino between the late 15th and the early 17th centuries. Raw materials, colouring agents and firing products were analysed in order to establish the production technology of the ceramic coatings, by means of detailed microtextural and chemical investigations. The pottery underwent two firing processes: the firing of the white slip-coated ceramic body and a further firing after application of the glaze. The homogeneity of the raw materials, white slip and glaze is remarkable, and demonstrates the use of well-established recipes with a constant supply of raw materials from the same places. Highly efficient kiln management during both firings is revealed by body,glaze interface reactions. [source] | ||||||||||