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Ceramic Foams (ceramic + foam)
Selected AbstractsEffect of Hypervelocity Impact on Microcellular Ceramic Foams from a Preceramic PolymerADVANCED ENGINEERING MATERIALS, Issue 11 2003P. Colombo A promising material for hypervelocity impact shields in spacecraft and satellites has been found in lightweight microcellular SiOC foams. The foam stops the projectile and the debris from the impacted bumper facesheet within a few millimeters (see Figure for a cross-section of the crater) at speeds up to 5.1 km,s,1. The impacted SiOC ceramic did not react with incoming debris, and no phase transformation or compositional change was observed. [source] Monolithic Ceramic Foams for Ultrafast Photocatalytic Inactivation of BacteriaJOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 8 2009Pinggui Wu Palladium-modified nitrogen-doped titanium dioxide (TiON/PdO) foams were synthesized by a sol,gel process on a polyurethane foam template. The TiON/PdO foam was tested for microbial killing using Escherichia coli cells as a target. Under visible-light illumination, the TiON/PdO foam displayed a strong antimicrobial effect on the bacteria cells in water. The antimicrobial effect was found to be dependent on the palladium content and the calcination temperature. In a flow-through dynamic photoreactor, the new photocatalyst efficiently inactivated E. coli within a short contact time (<1 min), the shortest ever reported for the photocatalytic killing of bacteria. The strong antimicrobial functions of the TiON/PdO foam were related to charge trapping by PdO and the high contact efficiency of the foam structure. [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] Novel Microcellular Ceramics from a Silicone ResinJOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 1 2004Paolo Colombo Microcellular silicon oxycarbide open cell ceramic foams were fabricated from a silicone resin. Microcellular foams, with a cell size ranging from ,1,80 ,m, were fabricated using poly(methyl methacrylate) microbeads as sacrificial templates. The compression strength of the foams decreased with increasing cell size. [source] | ||||||||||