Papers by Keyword: Quasicrystal

Paper TitlePage

Authors: Ja Min Koo, Sung Kang Hur, Kee Sam Shin, Jong Soo Bae
Authors: Ya Lin Lu, Ling Li, Karen A. Reinhardt
Abstract: Enhancing absorption of solar cells over the solar spectrum is one of the most important ways to improve such devices’ performances. In this research, two-dimensional surface photonic designs were suggested to introduce rotationally distributed reciprocal vectors, which will match the guiding modes of the thin planar layer of an active material, and thus to further couple the incident light laterally into the layer. This allows the use of a fewer amount of active materials, increases the devices’ angle acceptance, and reduces costs for both fabrication and system installation.
Authors: Jaqueline Dias Altidis, Silvio Romero de Barros, João Dellonx Régis Barboza de Souza, Sandro Marden Torres, Severino Jackson Guedes de Lima
Abstract: The composite studied here consisted of a geopolymer matrix reinforced with quasicrystal powders. Quasicrystals are complex metal alloys with atypical structures. Due to their physical, mechanical and surface properties, quasicrystals have been widely studied. Nowadays quasicrystalline powders are proposed to be incorporated in ductile matrices. The geopolymers are inorganic polymers with excellent thermal performance and interesting adhesive properties. The quasicrystalline alloys were prepared by induction melting the constituents under argon atmosphere in a water-cooled copper crucible. In this work the adhesion of composites with 5, 10 and 15% of quasicrystal powder in aluminum joints was investigated. In addition, the influence of the curing time was taken in to account and tests were performed in samples with 7 and 28 days of cure. The results indicate an improvement in adherence with the inclusion of quasicrystal. The best adherence was obtained when the curing time was 28 days.
Authors: E. Belin, Z. Dankhazi, D. Mayou, G. Trambly de Laissardière
Authors: Atsushi Yamamoto, Akikazu Sato, Koji Kato, An Pong Tsai, Tsuyoshi Masumoto
Authors: Jacek Krawczyk, Włodzimierz Bogdanowicz, Grzegorz Dercz, Wojciech Gurdziel
Abstract: Microstructure of terminal area of Al65Cu32.9Co2.1 ingots (numbers indicate at.%), obtained via directional solidification was studied. Scanning Electron Microscopy, Transmission Electron Microscopy and X-ray powder diffraction were applied. Point microanalysis by Scanning Electron Microscope was used for examination of chemical compositions of alloy phases. It was found that tetragonal θ phase of Al2Cu stoichiometric formula was the dominate phase (matrix). Additionally the alloy contained orthogonal set of nanofibres of Al7Cu2Co T phase with the average diameter of 50-500 nm and oval areas of hexagonal Al3(Cu,Co)2 H-phase, surrounded by monoclinic AlCu η1 phase rim. Inside some areas of H-phase cores of decagonal quasicrystalline D phase were observed.
Authors: Włodzimierz Bogdanowicz, Jacek Krawczyk, Robert Albrecht
Abstract: Composite based on Al–Cu–Co alloy obtained by directional solidification, were characterized. The quasicrystalline decagonal D phase of Al64Cu20Co16 was the reinforcement and the singlecrystalline tetragonal T phase of Al72Cu27Co1 was the matrix of the composite. The phases were identified by powder X-ray diffraction (XRD). The composite was analysed by light optical microscope and electron microscopes. The SEM and TEM techniques were used. Additionally the Laue method was used. The results of the study showed that the reinforcement has a form of parallel fibres of 20-40 μm diameter. Quasicrystal structure of fibres contained the phason strain. The quasicrystalline phase in the form of decagonal columns was also present inside composite pores.
Showing 1 to 10 of 137 Paper Titles