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Microstructure Characterization (microstructure + characterization)
Selected AbstractsMulti-scale Microstructure Characterization of Solid Oxide Fuel Cell Assemblies With Ultra Small-Angle X-Ray Scattering,ADVANCED ENGINEERING MATERIALS, Issue 6 2009Andrew J. Allen Ultra small angle X-ray scattering with synchrotron radiation is applied to assess the pore space of a highly complex solid oxide fuel cell assembly. The instrument permits to record scattering curves covering a size range from 1,nm to several ,m in a fine step width of 15,,m. [source] Microstructure Characterization of Tool Steel Claddings Co-Extruded on Low Alloyed Steel Substrates,ADVANCED ENGINEERING MATERIALS, Issue 5 2009Pedro Augusto da Souza e Silva Low-alloyed steel bars are hot extruded with pre-sintered tool-steel powders with or without the addition of tungsten carbides (W2C/WC) as hard particles. An extrudate is formed consisting of a wear resistant coating layer and a bulk steel bar as the substrate core. The microstructure at the interface between coating and substrate of different coatings is characterized using OM, SEM and EBSD. [source] Co3O4 Nanoboxes: Surfactant-Templated Fabrication and Microstructure Characterization,ADVANCED MATERIALS, Issue 8 2006T. He Co3O4 nanoboxes (see figure), prepared by a template-synthesis process and composed of compactly assembled cuboid Co3O4 nanocrystals, are reported. Heterogeneous nucleation and interparticle coarsening growth of the nanocrystals is proposed as the formation mechanism. These nanoboxes are characterized by their unexpected magnetic behavior, and may lead to the possibility of novel metal oxide hierarchical structures. [source] Microstructure Characterization of the (1,x)La2/3TiO3·xLaAlO3 SystemJOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 8 2003Hwack Joo Lee Microstructural characterizations on the (1,x)La2/3TiO3·xLaAlO3 (LTLA) system were conducted using transmission electron microscopy. The presence of La2Ti2O7 and La4Ti9O24 phases in pure La2/3TiO3 is confirmed by the electron diffraction pattern. When x= 0.1, the ordering due to the A-site vacancies could be confirmed by the presence of antiphase boundaries (APBs) and return ½(100) superlattice reflection. As xincreases, the ordering decreases and finally disappears when x= 0.6. The tilting of oxygen octahedra could be demonstrated by the presence of the ferroelastic domains in the matrix and return ½(111) and return ½(110) superlattice reflections in selected area electron diffraction patterns. In pure LaAlO3, only the antiphase tilting of oxygen octahedra is present due to the presence of return ½(111) superlattice reflection. In the LTLA system of x= 0.1, both the antiphase and in-phase tiltings of the oxygen octahedra are involved; however, in the range of x from 0.3 to 0.9, the antiphase tilting of oxygen octahedra has appeared. The growth of the ferroelastic domains is influenced by the APBs in the matrix. [source] Microstructure Characterizations in Calcium Magnesium NiobateJOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 7 2001Hwack Joo Lee Microstructural studies on the domain boundaries in Ca(Mg1/3CNb2/3)O3 (CMN) complex perovskite compound were conducted using X-ray diffractometry and transmission electron microscopy. The 1:2 chemical ordering of B-site cations and the tilting of oxygen octahedra were involved in the CMN microstructure, as inferred from the presence of two types of domain boundaries. One type was the antiphase boundaries (APBs), which did not lie on a specific set of crystallographic planes. These boundaries were caused by the chemical 1:2 ordering of B-site cations, magnesium and niobium. The other type was the ferroelastic domain boundaries, which were parallel to a certain crystallographic plane. Therefore, CMN had the 1:2 ordered monoclinic unit cell distorted by the antiphase or in-phase tilting of oxygen octahedra. CMN had the mixed phases rather than the homogeneous phase. [source] Preparation and microstructure characterization of ball-milled ZrO2 powder by the Rietveld method: monoclinic to cubic phase transformation without any additiveJOURNAL OF APPLIED CRYSTALLOGRAPHY, Issue 5 2002S. Bid The phase transformation kinetics of high-energy ball-milled monoclinic ZrO2 have been studied in detail by Rietveld powder structure refinement analysis. In the present study, no stabilizing compound was required to obtain the cubic phase. The fine-grain powder was milled in a planetary ball mill for up to several hours at different BPMRs (ball to powder mass ratios): 10:1, 20:1, 35:1 and 40:1. During the process of ball milling, the monoclinic phase is gradually transformed to the cubic phase. The relative phase abundances of the respective phases, the particle sizes, the r.m.s. strains, the lattice parameter changes, etc., have been estimated from Rietveld analysis of X-ray powder diffraction data. It has been found that a higher BPMR exerts more influence on rapid phase transformation. In the m - to c -ZrO2 phase transformation, no formation of an intermediate tetragonal ZrO2 phase has been found. The small change in the lattice volume of m -ZrO2, which is very close to the lattice volume of c -ZrO2, caused by ball milling may be attributed to this phase change. The formation of the c phase is noticed, in general, after just 1,h of ball milling, and the particle size of the m phase is reduced to a large extent at the first stage of milling and remains almost unchanged with increasing milling time. However, the particle size of the c phase increases with increasing milling time for the samples milled with higher BPMRs (35:1 and 40:1), suggesting that quenching caused by a high impact energy followed by an annealing effect may play a vital role, which is further manifested in the agglomeration of small particles. [source] Electrochemical performance and microstructure characterization of nickel yttrium-stabilized zirconia anodeAICHE JOURNAL, Issue 6 2010Jingbo Liu Abstract A nickel and yttrium-stabilized zirconia (Ni-YSZ) composite is one of the most commonly used anode materials in solid oxide fuel cells (SOFCs). One of the drawbacks of the Ni-YSZ anode is its susceptibility to deactivation due to the formation of carbonaceous species when hydrocarbons are used as fuel supplies. We therefore initiated an electrochemical study of the influence of methane (CH4) on the performance of Ni-YSZ anodes by examining the kinetics of the oxidation of CH4 and H2 over operating temperatures of 600,800°C. Anode performance deterioration was then correlated with the degree of carbonization observed on the anode using ex-situ X-ray powder diffraction and scanning electron microscopy techniques. Results showed that carbonaceous species led to a significant deactivation of Ni-YSZ anode toward methane oxidation. © 2009 American Institute of Chemical Engineers AIChE J, 2010 [source] Quantitative microstructure characterization of self-annealed copper films with electron backscatter diffractionPHYSICA STATUS SOLIDI (A) APPLICATIONS AND MATERIALS SCIENCE, Issue 2 2008Karen Pantleon Abstract Electron backscatter diffraction (EBSD) was applied to analyze cross sections of self-annealed copper electrodeposits, for which earlier the kinetics of self-annealing had been investigated by in-situ X-ray diffraction (XRD). The EBSD investigations on the grain size, grain boundary character and crystallographic texture of copper films with different thicknesses essentially supplement results from in-situ XRD. Twin relations between neighboring grains were identified from the orientation maps and the observed twin chains confirm multiple twinning in copper electrodeposits as the mechanism of microstructure evolution at room temperature (self-annealing). (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] | |||||||||||||