MS&T'11 Poster Session: Ceramic and Glass Materials
Program Organizers: Chris Wood, TMS

Tuesday 11:00 AM
October 18, 2011
Room: Exhibit Hall C
Location: Greater Columbus Convention Center


031 Alumina-Based Composites Reinforced with Titanium Nanoparticles: Enrique Rocha1; José A. Rodríguez-García1; Sergio Mundo-Solís2; Juliana G. Gutiérrez-Paredes2; Elizabeth Refugio-García3; 1Universidad Politecnica de Victoria; 2ESIME-IPN; 3Universidad Autónoma Metropolitana
    The effect of titanium nanoparticles additions on the fracture toughness of Al2O3-based composites is explored in this study. Mixtures of alumina with different titanium amounts (0.5, 1, 2, 3 wt %) were high energy grinded in a Symoloyer mill during 8h. After milling, the powder was constituted by very fine particles of 200 nm average sizes, presenting good distribution between titanium and alumina particles. Microstructure observations by electron microscopy of uniaxial compacted and pressureless sintered samples, illustrate dense composite materials with a fine and homogeneous distribution of titanium in the alumina-matrix. From fracture toughness measurements, estimate by the fracture indentation method, it has determined that titanium additions has improved fracture toughness until more than 50% with respect to the fracture toughness of monolithic-alumina. This behavior can be due to the formation of metallic bridges by titanium in the alumina-matrix.

032 Analysis of Load-Displacement Curve by Hertzian Indentation for Thermal Barrier Coating Durability: Kee Sung Lee1; Dong Heon Lee1; Yeon-Gil Jung2; 1Kookmin Unviersity, South Korea; 2Changwon University, South Korea
    Hertzian indentations using micrometer-sized spherical indenter are used for evaluating mechanical properties and predicting thermomechanical durability. The load-displacement curves by spherical indentation predict the hardness and elastic modulus. The curves also give information on interface delamination during loading/unloading of indentations. In this study we prepared multi-layered thermal barrier coatings using different size distributions of starting powders and new plasma processing including multiple guns for denser coatings. Relatively dense, porous, dense/porous and porous/dense thermal barrier coatings are prepared controlling by starting powders and process parameters. Thermal shock tests were conducted from 1150oC to room temperature until several hundred of cycles. After thermal shock tests, we analyzed the indentation load-displacement curve by Hertzian indentations on the prepared thermal barrier coatings. The results indicate that Hertzian indentation is one of the simple and reliable evaluation techniques to predict a deterioration of mechanical properties of ceramic coatings.

033 Characterization of Ceramic Powders during Compaction Using Electrical Measurements: Timothy Pruyn1; Rosario Gerhardt1; 1Georgia Tech
    The use of ceramic composites with percolated segregated microstructures of conductive filler has numerous potential applications. Our focus is to optimize the green state of ceramic compacts by minimizing the conductive filler needed for percolation. In this study we evaluated the electrical response of ceramic compacts during dry pressing as a function of applied pressure. Semiconductive SiC and insulating Al2O3 powders were used for the experiments. A custom made die with an insulating outer sleeve was used to carry out dc and ac measurements. Measurements were performed in situ as a function of loading and unloading compaction pressure. Dc measurements can only detect the combined response from the powders and the porosity. However, from the complex impedance plot, at least two semicircles were observed. One of these semicircles represents the bulk material property, while the other is likely due to the void space and interfaces.

034 Colloidal Processing of Diamond Particles for Diamond Film Fabrication on Graphene and Silicon Substrates: Brian Babcox1; David Snyder1; James Adair1; 1The Pennsylvania State University
    The growth of diamond films is a complex, intensive process involving specific substrates or seed layers. Due to these issues, the ability to attach and pattern polycrystalline diamond to various substrates for use as a seed layer is of great interest. Diamond films can allow one to take advantage of diamond’s high hardness for mechanical applications and high thermal conductivity for use as a heat sink in electronic applications. A colloidal protocol was developed, based on established conjugation techniques, to covalently attach sonicated nanodiamond particles to a variety of substrates. Using the developed protocol, nanodiamond was covalently bound to graphene and silicon substrates, creating polycrystalline layers of various thicknesses. Control of the film thickness was looked into by modifications of diamond size, monodispersity, and the amount used in the formulated protocol. Characterization was performed on the diamond – particle bonding as well the diamond particles that were created from sonication.

035 Copper (I) and (II) Containing Waveguiding Layers in Novel Silicate Glass: Hana Malichová1; Jarmila Spirkova1; Martin Mika1; Stanislava Stara1; 1ICT Prague
     Copper containing optical waveguides as promising candidates for applications in sophisticated integrated optics structures operating in visible/NIR spectral regions were fabricated by ion exchange of Cu+ and/or Cu2+ in specially formulated glasses having different optical basicity and containing optionally also erbium and by Ag+ exchange in copper containing novel glasses. The crucial factor of their function is oxidation states of Cu and how to affect it by preparation conditions and the substrate glass. These factors were evaluated by measuring the characteristics of the waveguides as their mode spectra, depth concentration profiles of Cu/Ag ions and photoluminescence properties. The Cu+ containing samples had very strong blue-green luminescence, which wavelengths was strongly affected by locations (coordination) of the Cu+ ions in the glass matrixes depending on the composition of the glass and allowing thus for feasible tuning the wavelength of the emission. Financial support: GACR 106/09/1937 and IGA 21/2011-101881192

036 Correlation between Structure and Electronic Properties in Y1-xPrx Ba1.9Sr0.1 Cu3O7-δ High Tc Superconductors: Muna Abbas1; 1Baghdad University
    Solid state thermodynamical reaction method involving mixing, calcinations and sintering were used to prepare high temperature superconductor with a nominal composition Y1-xPrxBa1.9Sr0.1Cu3O7-δ for Pr (0.1≤ x≤ 0.5). The effect of the substitution of Pr on Y sites and Sr for Ba sites, sintering time, annealing temperature and oxygen content of the superconductivity has been investigated to obtain the optimum conditions for the formation and stabilization of the superconducting samples. The critical temperature TC of the samples prepare with different conditions were 88K, 86, 88 and 86 for x=0.1, 0.2, 0.3 and 0.4 respectively. X-ray diffraction analysis showed single phase with orthorhombic structure for all samples.

037 Critical analysis of experimental methods for reliable oxidation rate measurements of ultra-high temperature ceramics using thermal gravimetric analysis up to 1600°C: Melia Miller-Oana1; Luke Walker1; William Pinc1; Erica Corral1; 1University of Arizona
    During hypersonic flight, vehicles need materials such as ultra-high temperature ceramics for thermal protection system in order to withstand temperatures greater than 2000˚C; therefore, understanding the oxidation behavior of these materials is important. We examine oxidation behavior of ZrB2-SiC composites by investigating the ratio of total specimen edge length to total specimen surface area and determine its relevance for developing reliable oxidation methods. In situ mass gains during ZrB2-SiC oxidation are measured with thermogravimetric analysis. Reproducible oxidation rates are not obtained due to varying edge length and surface area of ZrB2-SiC composites. Using identical conditions, mass gains during heating to 1400°C range from 0.93% to 0.14% for total specimen edge length to surface area ratios of 1.28 and 0.33, respectively. For reliable data, sample parts with ratios less than 0.5 should be used for oxidation testing due to the reduced effect of edge and corner oxidation compared to bulk oxidation.

038 Design and Development of Dichroic Glasses: Julie Dalbey1; S.K. Sundaram1; John Rich1; 1Alfred University
    Selected glass chemistries, 75 wt% B2O3 and 25 wt% Na2CO3, as well as clear Moretti art glass, were used for the study. A series of set of dopants (for example, neodymium and praseodymium) was tested for ranges of colors, keeping the art glass industry in mind. The base glasses were mixed with the sets of dopants and remelted above 1100°C under ambient atmosphere for about 1 h and quenched by pouring on a graphite surface. The samples were polished into small disks of approximate dimensions of 1 mm thick and 5 mm diameter for characterization. UV-Vis-NIR, Raman, and FTIR spectroscopic techniques were used to characterize the optical and structural properties of the glasses. This dichroism and its stability in these glasses were studied in terms of colloids/nanocrystals formed.

039 Effect of % Boron on the Tribological Performance of Alumina Matrix Multifunctional Composites for Energy Efficient Sliding Systems: Rajeshwari Paluri1; Sudeep Ingole1; 1Texas A&M University
    With upcoming stringent norms to improve energy efficiency and environmental safety, reducing frictional losses of the sliding systems are crucial. Newly developed alumina matrix multifunctional composites (AMMCs) showed promising mechanical properties and frictional performance. AMMCs have potential applications in low friction applications due the presence of low friction components in the matrix. AMMCs were synthesized using powder compaction. To optimize the composition of reinforcement (boron) and to correlate the structure and properties, it is important to understand the effect of reinforcement on the in-situ phase formation and their subsequent effect on the friction and wear properties. Therefore, this study will discuss the effect of boron on in-situ phases and friction and wear of AMMCs. It was found that sintering temperature, composition of reinforcement have influence on the friction and wear resistance of these composites. The wear resistance of the composite was better than alumina.

040 Effect of Neutrons on the Microstructure Properties of Hg1-x-yTlxPbyBa2Ca2Cu3O8+δ for (0≤x≤0.4) and (0≤y≤0.4) System: Ghazala Hermiz1; Maysoon Alias1; Bushra Aljurani1; 1baghdad university-college of science
    Scanning electron microscopy (SEM) has been used to identify the morphology of the superconducting phase and to investigate the influence of doping effect on the prepared samples before and after irradiation with thermal and fast neutrons. The microstructure for most samples before irradiation was found to be dense and the morphology of these samples shows needle-like and plate–like layered microstructure for different compositions. While irradiation with fast and thermal neutrons induced more voids and defect in most of the samples.

041 Effect of Spark Plasma Sintering to the Structure and Some Properties Development for Mullite-Zro2 Ceramics: Gaida Sedmale1; Ingunda Spergerga1; Ints Steins1; 1Riga Technical University, Institute of Silicate Materials
    Spark Plasma Sintering (SPS) for the two kinds of powder compositions of Al2O3, SiO2 - gel, ZrO2 and Y2O3 with and without mineralizer, illite clay, prepared by milling, as well as hydrothermal synthesized was used to produce mullite-ZrO2 ceramics. Some obtained results have been compared with the characteristics of a mullite–zirconia ceramics fabricated by conventional sintering reactions. It is shown that submicronic powder has enabled to obtain sample with relative density up to 98-100 % at temperatures starting from 12000C. The mullite and ZrO2 cubic is the main phases in obtained ceramic. Microstructures are uniform and dense and are formed from good textured mullite crystals and cubic ZrO2 equally dispersed particles in mullite matrix. The pressure strength of ceramic samples values correlate with the tendency of density, i.e. the higher compressive (the maximum of 420 MPa) reaches the samples sintered.

042 Effect of Temperature on the Hydration of Activated Granulated Blast Furnace Slag: Enrique Rocha1; M. Juana Martínez-Alvarado2; Manuela Diaz-Cruz2; 1Universidad Politecnica de Victoria; 2ESIQIE-IPN
    In this work it was carried out a study on the hydration products formed by the activation with NaOH of granulated blast furnace slag at different temperatures (25, 50, 100 and 150°C), as a function of time (1, 3, 7, 14 and 28 days). The progress of hydration reactions was assessed by X-ray diffraction and infrared spectroscopy. From these analyses they were found that the main product of hydration was calcium silicate hydrate (CSH-gel), whose formation is favored with increasing hydration temperature. Also hydrotalcite was formed in significant amounts for the different studied conditions. At high temperatures (100 and 150°C) were formed tobermorite and ettringite in small amounts. Monosulphoaluminate and brucite phases were formed from 50°C. The results show the presence of calcite because the slag absorbs atmospheric CO2. Due to the high amount of MgO in the slag it was detected the formation of dolomite at high temperatures.

043 Fabrication and Corrosion Behavior of Ti-Based Bulk Metallic Glass Composites Containing Carbon Nanotubes: Pee-Yew Lee1; 1National Taiwan Ocean University
    This study explored the feasibility of preparing Ti50Cu28Ni15Sn7 bulk metallic glass composite with powder metallurgy route.The CNT/Ti50Cu28Ni15Sn7 metallic glass composite powders can be formed with mechanical alloying after 8 h milling. The bulk metallic glass composite was successfully prepared by vacuum hot pressing the as-milled CNT/Ti50Cu28Ni15Sn7 metallic glass composite powders. The corrosion behavior of the Ti50Cu28Ni15Sn7 bulk metallic glass as well as composites modified by the addition of CNT was investigated by electrochemical measurements. Electrochemical characterization was performed in Hanks’ solution at 37 ℃ with physiologically relevant dissolved oxygen content. The results of potentiodynamic polarization measurements revealed that the Ti-based bulk metallic glass composites examined showed spontaneously passivity by anodic polarization with a passive current density of about 10-5 A/cm2. The higher corrosion resistance of the Ti-based bulk metallic glass composites was attributed to stable and protective passive films enriched with titanium containing certain amounts of additional elements.

044 Fabrication of ZrO2-SiC Composites from Natural Zircon Ore by Carbothermal Reduction: Youguo Xu1; Zhaohui Huang1; Yan-gai Liu1; Minghao Fang1; Xin Ouyang1; Li Yin1; 1China University of Geosciences (Beijing)
    ZrO2-SiC composite powders were synthesized from natural zircon ore by carbothermal reduction in immerged carbon coke and the influences of CaO, Y2O3 and TiO2 additives on the phase composition and the microstructure of the products were investigated. The phase composition and microstructure of the products were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The results show that ZrO2-SiC composite powders could be obtained from natural zircon ore by carbothermal reduction between 1500oC and 1650oC for 4h and the ideal synthetic requirement is 1600oC using carbon black as reducing agent. The phase composition of zirconia in the products with 8wt.% CaO, Y2O3 or TiO2 exists in the form of tetragonal zirconia, cubic zirconia and monoclinic zirconia respectively.

045 Fracture Toughness Properties of WC-10Co Cemented Carbide Containing VC or (Ta, Nb)C Additives: Amir Masoud Soleimanpour1; 1Sharif University of Technology
    In this research Wc-10Co carbides produced by P/M method following by hot isotactic press(HIP), and VC and (Ta,Nb)C) were used as grain growth inhibitors to improve microstructure and mechanical properties of WC-10Co cemented carbide. The mechanical and microstructure of the samples were studied to compare the effect of grain growth inhibitors on properties of composites. The Hardness, transverse rupture strength and indentation fracture toughness (IFT) tests were also used for the specimens.

046 Gelcasting Process of Fused Silica-Boron Nitride Composite Ceramics: Lizhong Zhou1; Dechang Jia2; 1The Chinese Ceramic Society; 2Institute for Advanced Ceramics, Harbin Institute of Technology
    In this paper, fabrication process of SiO2-BN composite ceramics by aqueous gelcasting method is studied. The rheological properties of SiO2-BN composite powders in aqueous media is correlated with the electrophoreic behavior, pH value, dispersant content and ball-milling time, etc., SiO2-BN slurry with well fluidity and high solids loading is obtained. It is shown that a premixing solution containing 15wt.% monomer can provide sufficient flexural strength for the green body for 50vol.% SiO2-BN slurry. Fracture photographs illustrate that the starting powders in the green body packed closely due to the polymer networks. The phase composition, relative density, mechanical property and microstructure of the final samples are significantly influenced by the addition of BN. The crystallization of amorphous silica was refrained, the relative density, the flexural strength, fracture toughness and Young’s modulus of SiO2-BN composite materials firstly increased and then decreased with the increase of BN content.

047 Glass-Ceramic Composites for High Energy Density Capacitors : Venkata Puli1; Ashok Kumar1; Reji Thomas1; Douglas Chrisey2; Minoru Tomazawa2; Ram Katiyar1; 1University of Puerto Rico; 2Rensselaer Polytechnic Institute
    A glass-ceramic composites of {Ba(Zr0.2Ti0.8)O3}(0.85){(Ba0.7Ca0.3)TiO3}0.15 and alkali free glass: BaO-B2O3-ZnO,were mixed with 10% volumetric of glass for high energy density (Ed) capacitor materials. Fabricated composites showed high ε, low loss and moderate breakdown voltage. The ceramic materials were prepared using high energy ball milling for 4 hrs at 400 rpm. The milled powders were calcined at 1250ºC/10hrs. Ceramic pellets were prepared using hydraulic press (2 ton) and sintered at 1500ºC/4 hrs. Glass compositions mentioned above were mixed with ceramic powders and milled for 2hrs. Glass-ceramic pellets sintered at 900ºC/4hrs. XRD studies of the sintered pellets revealed the rhombohedral/pseudo cubic crystal structure with composite behavior. The crystal structure was further confirmed by Raman spectra and SEM analysis. High ε and moderate Ps~13µC/cm2 were obtained in the sintered pellets. The SEM revealed monolithic grain growth. Preliminary data show moderate breakdown field 60kV/cm and Ed of ~1.5 J/cm3. Detailed results will be presented.

048 Improving PZT Thin Film Texture through Pt Metallization and Seed Layers: Luz Sanchez1; Daniel Potrepka1; Glen Fox2; Ichiro Takeuchi3; Ronald Polcawich1; 1Army Research Laboratory; 2Fox Materials Consulting LLC; 3University of Maryland
    A study was performed between Ti/Pt and TiOx/Pt bottom electrodes to achieve a high degree of (001) texture and improve piezoelectric properties. The results indicate the use of a highly oriented TiOx led to highly textured (111) Pt which improved both the PbTiO3 (PT) seed layer and PZT orientations. PZT (52/48) and (45/55) thin films with and without PT were examined via x-ray diffraction methods (XRD). The PT provides improvement in the (001) orientation while suppressing the (111) orientation of the PZT. A 30% increase in deflection has been demonstrated and attributed to an increase in texturing in samples where the lotgering factor (f) has been assumed to vary from ~0.87 to ~0.96 based on earlier x-ray diffraction measurements. The dielectric constant values track accordingly varying from 863 (f=0.66) to 1010 (f=0.87) to 1343 (f=0.95) while the ferroelectric data exhibits only minor changes as a function of the (001) texture.

049 Investigation of Effective Parameters in Production of A356/ TiB2p Composite using of TiB2p/CMC/PPS Mortar: Mohammad Hizombor1; S.M.H. Mirbagheri2; Azam Rezaie3; Reza Abdideh1; 1khouzestan oxin steel co.; 2Amirkabir University of Technology; 3Islamic Azad University
    In this investigation, an innovation procedure has been proposed for casting of metal matrix composites by adding a mortar consist of expandable polystyrene beads, carboxy methyl cellulose paste, water and TiB2p particles as a mould pattern. This process was examined for A356/TiB2p composite. The use of pretreated TiB2p particles, 1wt% magnesium as a wetting agent and mechanical mold vibration while MMCs slurry is solidifying were found to promote wettability of TiB2p with molten matrix alloys. Produced composites were characterized using optical and scaning electron microscopy. Then mechanical properties of the composites, such as hardness, wear, tensile testing and porosity levels of produced Al/TiB2p composites were measured and results has been discussed. Results show the mechanical properties strongly dependent on the distribution of the TiB2p particles.

050 Investigation of ZnO:N and ZnO:(Al,N) Films for Solar Driven Hydrogen Production: Sudhakar Shet1; Yanfa Yan1; Nuggehalli Ravindra2; Heli Wang1; John Turner1; Mowafak Al-Jassim1; 1National Renewable Energy Laboratory; 2New Jersey Institute of Technology
    ZnO thin films with significantly reduced bandgaps were synthesized by doping N and co-doping Al and N at 100oC. All the films were synthesized by radio-frequency magnetron sputtering on F-doped tin-oxide-coated glass. We found that co-doped ZnO:(Al,N) thin films exhibited significantly enhanced crystallinity as compared to ZnO doped solely with N, ZnO:N, at the same growth conditions. Furthermore, annealed ZnO:(Al,N) thin films exhibited enhanced N incorporation over ZnO:N films. As a result, ZnO:(Al,N) films exhibited improved photocurrents than ZnO:N films grown with pure N doping.

051 Manufacture and Mechanical Characterization of Polymer-Composites Reinforced with Natural Fibers: Enrique Rocha1; Ernesto Benavides-Hernández1; Jose A. Rodríguez-García1; Alejandro Altamirano-Torres2; Y. Gabriela Torres-Hernández2; Francisco Sandoval-Pérez2; 1Universidad Politecnica de Victoria; 2Universidad Autónoma Metropolitana
    This work shows the experimental results obtained from the mechanical characterization of a biopolymer-composite reinforced with coconut fibers. Firstly, coconut fibers were dried at 80°°C during 2, 3, 4, 5 and 6h, in order to know the best wet condition for their performance under loads action. Results of tensile test executed on fibers, show that the best dried time was 3h, due to maximum stress reached was 76.15MPa. For longer times, this property decrease significantly (4h = 18.13MPa, 5h = 20.31MPa and 6h = 19.10 MPa). Specimens of biopolymer-composite reinforced with coconut fibers were fabricated by extrusion techniques using the temperature range between 140°C and 160°C. From results it is observed rough surface of material when samples are extruded at 160°C. As a result, the best determined conditions for the fabrication of the composite material were; 3 h of dried, 150°C extrusion temperature and coconut fiber length of 1–3 mm.

052 Microstructure and Properties of Al2O3 Ceramic Composite Toughened by Different Grain Sizes of LiTaO3: Yan-gai LIU1; Minghao FANG1; Zhaohui HUANG1; Shaoping HUANG2; 1China University of Geosciences (Beijing); 2Luoyang Precondar Heat-resistant Testing Equipment Co.Ltd.
    Abstract: Different grain sizes of LiTaO3 was added into Al2O3 to prepare LiTaO3/Al2O3 ceramic composites by hot pressing. The effect of LiTaO3 grain size on microstructure and properties of Al2O3 was investigated. The addition of LiTaO3 powders contributed to the sintering of Al2O3 and the relative density of the LiTaO3/Al2O3 ceramic composites was more than 96%. Non-180° domains formed in the composite and were regardless of the grain sizes of LiTaO3. The bending strength and fracture toughness of Al2O3 were improved by adding different grain sizes of LiTaO3. The mechanism of formation of non-180° domains was concluded to be stress induced mechanism. The toughening mechanisms of LiTaO3/Al2O3 ceramic composite with LiTaO3 was the co-operating effect of crack deflection and energy dissipation due to domain switching.

053 Polymer-Derived Mesoporous SiOC/ZnO Nanocomposite for Water Decontamination: Mirabbos Hojamberdiev1; Ravi Prasad1; Koji Morita1; Ralf Riedel1; 1Technische Universitaet Darmstadt
    The polymer-to-ceramic transformation generally results in the release of gaseous products that leave behind a variety of pores. These porous materials can be applied as good adsorbents for various organic water contaminants. However, they cannot be employed to decompose organic adsorbates due to their low solid acidity. Oxide catalysts like TiO2, ZnO, WO3, F2O3, etc. are known to possess high solid acidity for photodegradation of organic compounds. In this work, ZnO was incorporated into polydimethyl siloxane followed by pyrolysis at 700°C to obtain porous SiOC/ZnO nanocomposites and their adsorption and photocatalytic activities were studied. The specific surface area of SiOC/ZnO porous ceramics (pore-size ~4 nm) was lower than that of pure SiOC ceramics (pore-size <2 nm). Pure SiOC porous ceramics showed no significant adsorption and photocatalytic activity for methylene blue due to its high microporosity and low solid acidity, respectively, whereas mesoporous SiOC/ZnO nanocomposite demonstrated higher adsorption and photocatalytic activity.

054 Processing and Mechanical Properties of Bulk and Multilayer ZrB2 Using Tape Casting and Spark Plasma Sintering: David Pham1; William Pinc1; Luke Walker1; Erica Corral1; 1University of Arizona
    Zirconium diboride (ZrB2) is an ultra-high temperature ceramic (UHTC) with properties that make it ideal for use as thermal protection system (TPS) materials for advanced hypersonic applications. To enable advanced TPS structures, advanced processing methods using spark plasma sintering (SPS) and tape casting have been investigated. The focus of this study is on the processing and densification of monolithic bulk ZrB2 through conventional powder processing methods and ZrB2 made using the tape casting method and SPS without using sintering additives. An organic solvent-based tape casting formula is developed to produce thin, flexible and homogeneous tapes. A lamination temperature and a binder burnout schedule are derived from thermal gravimetric analysis of ZrB2 tapes. A discussion on microstructure, densfification behavior and mechanical properties of fully dense bulk ZrB2 and tape casted ZrB2 will be presented.

055 Processing of Alumina-Rich Spinel Nanopowders Made by Liquid Feed Flame Spray Pyrolysis (LF-FSP) to Fine-Grained Ceramic Composites: Andrew Pottebaum1; Richard Laine1; 1University Of Michigan
    Liquid feed-flame spray pyrolysis (LF-FSP) provides ultrafine and nanosized metal-oxide powders by combustion of metallo-organic precursors dissolved in alcohol. In some cases, LF-FSP provides access to metastable phases. For example in MO-Al2O3 systems, 1MO:3Al2O3 [M = Mg, Co, Ni] mole ratio nanopowders are phase-pure spinel nanopowders. Compacts of these materials phase segregate on heating forming the thermodynamically-stable α-alumina/spinel composites. Our objective is to synthesize fine-grained Al2O3-MgAl2O4, Al2O3-CoAl2O4, and Al2O3-NiAl2O4 composites with high fracture toughness. Current efforts have led to dense (≥ 95% of theoretical density) ceramic composites with grain sizes of a few microns. By increasing green densities and limiting grain growth during sintering, we hope to develop routes to transparent, polycrystalline nanocomposites for structural applications (e.g. Al2O3-MgAl2O4) as well as self-supported catalyst materials (e.g. Al2O3-CoAl2O4, and Al2O3-NiAl2O4) for use in wide variety of commercial applications such as steam reforming, hydrocarbon cracking, and dehydrogenization.

056 Processing–Electronic Property Relations for Y1-xPrx Ba2 Cu3O7-δ High TC Superconductors: Muna Abbas1; 1Baghdad University
    Solid state thermochemical reaction method involving mixing, calcinations and sintering, has been used to prepare high temperature superconductor with a nominal composition Y1-xPrx Ba2 Cu3O7-δ for Pr (0 ≤ x ≤ 0.5).The samples were studied to investigate the effect of preparation conditions and Pr substitution at Y sites on the superconducting properties. The critical temperature TC of the samples were 98, 96, and 87 K for x= 0.1, 0.2, and 0.3 respectively. X-ray diffraction analysis showed single phase with orthorhombic structure for all samples.

057 Properties and Fabrication of Carbon Nanotube Dispersed Al2O3 Composites by Spark Plasma Sintering : Byung-Koog Jang1; Yoshio Sakka1; Hideyuki Murakami1; Seiji Kuroda1; Kee-Sung Lee2; 1National Institute for Materials Science; 2School of Mechanical Engineering, Kookmin University
    Carbon nanotube-based nanotechnology has a great attention due to its superior properties, such as high aspect ratio, electrical and physical properties for biomedical application, optics, electronics, structural and functional composites. This work describes the development of the aligned carbon nanotubes (CNTs) dispersed Al2O3 composites using strong magnetic field and dispersion of CNTs. Commercially available multi-walled carbon nanotubes (MWNT) and proper dispersants were used to obtain the stable dispersion of CNTs. 0.001~10 wt% of as-received or length-controlled CNTs were suspended in aqueous solution and Al2O3 slurry. A strong magnetic field of 12 T was also applied to the CNTs dispersed Al2O3 slurry to obtain the alignment of the CNTs. Sintered bodies were obtained by SPS (Spark plasma sintering) of 1000~1500C in vacuum. The electrical conductivity of composites shows the increasing tendency with increasing the addition of CNTs. The effect of CNTs on mechanical properties of composites will be discussed.

058 Properties Optimization of Refractory Mineral Resources in China: Zhaohui Huang1; Minghao Fang1; Yan-gai Liu1; Juntong Huang1; Saifang Huang1; Wanzheng Zhu2; 1China University of Geosciences (Beijing); 2Beijing Weirunda Metallurgical Materials Co. Ltd.
    Refractory mineral resources are abundant in China, and can be utilized to fabricate advanced refractory products. It not only can improve the value of refractory minerals, but can boost the energy efficiency and reduce mineral wastes. In this paper, with the aim of reducing the increasingly serious energy shortage burden with the rapid economic development, some of our investigations on study on the high-performance utilization of refractory mineral resources were introduced, such as refractory clay, magnesite, bauxite, dolomite and quartz. Spinel-Sialon, Spinel/CA, and light-weight anorthite/mullite refractory composites were synthesized by various routes from those raw materials. Besides, a view of synthesizing Sialon powders from minerals and ores was also illustrated, based on the chemical composition analysis and structure feature of mineralogy characters. These might serve as new technical approaches for efficient utilization of mineral resources.

059 Raman Scattering as a Tool to Characterize the Changes of the Silicate Glass Structure after Ion Implantation: Blanka Svecova1; Pavla Nekvindova1; Anna Mackova2; Petr Malinsky2; Vladimir Machovic1; Milos Janecek3; Josef Pesicka3; Jarmila Spirkova1; 1Institute of Chemical Technology Prague; 2Academy of Sciences of the Czech Republic, v.v.i.; 3Charles University
    We demonstrate the utility of Raman spectroscopy as a technique for the characterization of changes of the glass structure caused by ion implantation. We studied the differences between various glasses implanted with gold ions and then annealed under the identical conditions. We focused on the depolymerization of the glass structure defined as ratio of Si–O stretching and bending modes and the analysis of the Qn components of the Si–O stretching mode envelope and discussed the relationship between Raman parameters and results obtained by Rutherford Backscattering Spectroscopy and Transmission Electron Microscope analysis. The results indicate depolymerization of the glass network after ion implantation, mainly in the depth of maximal Au concentration. Moreover, we found that the degree of depolymerization depends on the type of glass used and significantly influences nucleation of Au nanoparticles and their parameters and the non-linear optical effect as a consequence. Acknowledgement: GACR106/09/1937, LC06041, MSMT6046137302.

060 Structural Investigations on Yttria /Scandia Doped Ceria - Low Yttria Doped α - Alumina Composites, a New Electrolyte for IT-SOFC: Nicoletta Popescu-Pogrion1; Ionel Mercioniu1; Serban Cosntantinescu1; Jesus Tartaj2; 1The National Institute of Materials Physics; 2The Institute of Ceramics and Glass (ICV)
    The attractive properties of yttria/Scandia doped ceria, particularly the structural and material properties have led to vast research efforts to investigate, characterize and develop such materials. One of the main applications of this ceramic is in the solid oxides fuel cells for intermediate temperatures - IT-SOFC. The aim of this paper is the preparation and characterization of Y/Sc doped Ceria – low Y doped α- Al2O3, a new composite for IT-SOFC. The matrix (10mol %) Y/Sc: CeO2 and the reinforcement (150ppm) Y: α- Al2O3 –composite were obtained by: • co-precipitation route for 10ScSC • mechanical route, for 150Y: α-Al2O3. The nanopowders were subjected to a complete sintering route to obtain the sintered body .composites Phases identification was realized by XRD and selected area electron diffraction SAED. Particle/grain shapes, particle/grain size distributions, the mean value of particles/grain were determined by TEM, SEM, EDX and statistical investigations.

061 Study on Reaction between Refractories and Flux with Slagging-under-Load Test: Akinori KUSUBASHI1; Masaaki YAMAMOTO2; Kohichiroh KATAOKA2; Taijiro MATSUI2; Nozomu UCHIDA1; 1Nagaoka University of technology; 2Nippon Steel Corporation
    To investigate the influence of desulfurization flux on the degradation of refractories used in the secondary steel making degasser, the Slagging-under-Lord test was performed for the refractories. Specimens were Al2O3-MgO castable, MgO-C and MgO-Cr2O3 bricks. Desulfurization flux was CaO-CaF2-SiO2 system flux. From the results, Al2O3-MgO castable was softened greatly by the reaction with desulfurization flux, whereas MgO-C and MgO-Cr2O3 bricks were softened slightly under this condition. In the case of Al2O3-MgO castable, the degree of deformation was not proportional to the depth of penetration of the desulfurization flux but was dominated by the chemical reaction with the flux.

062 Substitution Grade Effect on the Synthesis and Magnetic Properties of Cu(Co,Zn)Fe2O4 Powders: Nora Sanchez-Padilla1; Antonio Fuentes2; Sagrario Montemayor1; 1Universidad Autonoma de Coahuila; 2Cinvestav del IPN
    Depending on chemical composition, spinel ferrites exhibit interesting catalytic, electrical or magnetic properties and thus, are promising candidates for a wide variety of technological applications. In particular, copper ferrite CuFe2O4 has recently deserved a great deal of attention because of its application in multilayer chip inductors. Properties in these materials depend very much on ions nature, their charge and distribution over the tetrahedral and octahedral sites. In order to improve the properties of the pristine material, partial substitution of copper by divalent cations such as nickel or zinc, has been suggested by different authors. Partially substituted CuFe2O4 powders have been obtained by the ceramic, hydrothermal, coprecipitation and sol-gel techniques with the synthesis method being crucial for controlling stoichiometry, particle size and size distribution. In this work we will present a study of Co and Zn substitutional grade effect, on CuFe2O4 powders synthesized by a polymerized complex route using poly(vinyl pyrrolidone).

063 Synthesis and Characterization of New Lead-Free Low Melt Sealing Glasses: Maik Peschel1; Jochen Schilm1; Alexander Michaelis1; 1Fraunhofer Institute for Ceramic Technologies and Systems
    Low melting lead oxide based glass solders are the state of the art. Due deleterious properties of lead and the constrictions of the RoHS, the development of lead-free solder glasses has been expanded. Besides Bi2O3 and ZnO also SnO is a promising replacement for PbO. SnO-based glasses have been investigated in several binary and ternary and more complex non silicatic oxidic and oxyhalides systems. SnO-based solder glasses have shown low Tg temperatures but also an insufficient stability against environmental corrosive conditions. Since borosilicate glasses are known to be more stable our study focused on the ternary SnO-B2O3-SiO2 glass system with SnO contents up to 70 mol-%. Glasses have been molten under a protective atmosphere in order to stabilize the divalent status of the SnO. The materials were characterized in terms of softening behavior, glass structure (XRD, FTIR, Raman spectroscopy) and oxidation behavior during the melting process.

064 Synthesis and Study of the Chemical Interaction of Strontium Sulfualuminate Sr4Al6O12SO4 with Molten Aluminum Alloys: Jose Rodríguez-García1; Enrique Rocha1; José Díaz-Rodríguez1; Jesús Torres-Torres2; Jose Almanza-Robles2; 1Universidad Politecnica de Victoria; 2CINVESTAV, Unidad Saltillo
    The strontium compound Sr4Al6O12SO4 was synthesized by solid state reaction, starting from stoichiometric mixtures of SrCO3, SrSO4 and Al2O3. Formation synthesis was determined from the guidance results of TGA, DTA, SEM and XRD. Also the chemical interaction between the compound Sr4Al6O12SO4 and molten aluminum alloys was studied following the immersion method. The obtained results showed that during synthesis of Sr4Al6O12SO4, at the range temperatures between 1000 and 1100°C two transitional phases (Sr3Al2O6 and SrAl2O4) were formed. Crystallization of Sr4Al6O12SO4 begins at 900°C and is completed at 1150°C. The Sr4Al6O12SO4 compound presents very favorable results in relation to chemical interaction with molten aluminum alloys because there was minimal chemical reaction with the Al-Si alloy and zero chemical reaction with the Al-Mg alloy.

065 Synthesis of Ni and NiCo-Y2O3 Nano Powders by Using a Solution Combustion Synthesis in an Air Atmosphere: Choong-Hwan Jung1; Young Min Han2; Sang Jin Lee2; Jin Sung Jang1; 1KAERI; 2Mokpo National University
    Nickel and NiCo-Y2O3 nano powders were made by using a solution combustion synthesis process. The exothermic redox reaction and the heat evolved from the reaction completely convert the precursors into their corresponding products at temperatures below 400°C in an oxidizing atmosphere. Ni-Y2O3 and NiCo-Y2O3 particles were directly synthesized through solution combustion synthesis with fuel-rich composition in air atmosphere without further reducing calcinations process. In the fuel-lean range and stoichiometric composition, metal oxide phase crystallized from the precursor mixture without forming any intermediate phases. The characteristics of synthesized particles were examined with an X-ray diffractometer, scanning electron microscopy (SEM), and transmission electron microscopy (TEM). Also, the characteristics of synthesized powders were examined with content of fuel.

066 Synthesis, Shaped and Mechanical Properties of Hydroxyapatite–Anatase Biomaterials: Roberto Nava-Miranda1; Enrique Rocha2; Lucia Téllez-Jurado1; 1ESIQIE-IPN; 2Universidad Politecnica de Victoria
    Hydroxyapatite powder was synthesized by the precipitation technique, starting from aqueous solutions of phosphoric acid and calcium hydroxide. To the hydroxyapatite powders were added 5, 10 or 20 wt % titanium oxide as a reinforcing agent. With the powder mixture it was manufactured a paste which was extruded into a solid cylinder using a steel die. Then the extruded tubes were sintered and characterized by XRD, SEM, IR and mechanically. XRD results show that in the sintered products are present crystalline phase’s hydroxyapatite and titanium oxide in anatase form, these phases also could be identified in the infrared analysis. The biomaterial’s microstructure presents equiaxed grains with sizes smaller than 5 microns. Microhardness and fracture toughness was similar to the values of human bone reported in literature of these same properties.

067 Thermal Behavior and Kinetics of Glass Transition in B2O3 Containing Tungsten-Tellurite Glasses: Miray Çelikbilek1; Ali Erçin Ersundu1; Duygu Yardımcı1; Süheyla Aydın1; 1Istanbul Technical University
    Thermal behavior and kinetics of glass transition in B2O3 containing tungsten-tellurite glasses was studied by using differential scanning calorimetry (DSC) and X-ray diffraction (XRD) techniques. Different compositions of the 0.80TeO2 - (0.20-x)WO3 - xB2O3 system (0 ≤ x ≤ 0.20 in molar ratio) were prepared with conventional melt-quenching technique at 750 °C and it was aimed to investigate the effect of B2O3 addition on the thermal behavior of tungsten-tellurite glasses. The kinetics of glass transition was studied under non-isothermal conditions and the glass transition activation energy, Eg, was determined by modified Kissinger equation.

068 Thermoplastic Extrusion of YAG Tubes: Nathan Taylor1; Richard Laine1; 1University of Michigan
    Liquid feed-flame spray pyrolysis (LF-FSP) combusts alcohol solutions of metalloorganics, producing unaggregated single and mixed-metal oxide nanopowders. We find that blends of these powders with ethylene vinyl acetate binder can be extruded to form 0.7 mm thick x 10 mm diameter x 70 cm long free standing composite tubes containing 50 vol % YAG composition that following burnout sinter to >95 %TD. Our goal is to produce optically transparent tubes for light transmission applications. Green densities following burnout were 45 %TD. We find reactive sintering of 3 Al2O3:5 Y2O3 produced >96 %TD using two-step sintering with a peak temperature of 1500°C/0 h and 1300 °C/20 h in vacuum. Final grain sizes were 1 to 2 µm. Alternately, tubes made with YAG composition nanopowders sintered to > 95 %TD only at 1600°C/3 h, with final grain sizes of 3 to 5 µm.

069 Zinc Oxide (ZnO) and Bandgap Engineering for Photoelectrochemical Splitting of Water to Produce Hydrogen: Sudhakar Shet1; Yanfa Yan1; Heli Wang1; Nuggehalli Ravindra2; John Turner1; Mowafak Al-Jassim1; 1National Renewable Energy Laboratory; 2New Jersey Institute of Technology
    We report material synthesis and characterization, and photoelectrochemical (PEC) measurements to explore methods to effectively reduce the band gap of ZnO for the application of PEC water splitting. We find that the band gap reduction of ZnO can be achieved by N and Cu incorporation into ZnO. We demonstrate that heavy Cu-incorporation lead to both p-type doping and band gap significantly reduced ZnO thin films. The p-type conductivity in our ZnO:Cu films is clearly revealed by Mott-Schottky plots. We further have successfully synthesized ZnO:N thin films with various reduced band gaps by reactive RF magnetron sputtering. The band gap reduction and photoresponse with visible light for N- and Cu-incorporated ZnO thin films are demonstrated.