Showing papers in "American Ceramic Society Bulletin in 1987"

Preparation of lead-based ferroelectric relaxors for capacitors

Abstract: On passe en revue des travaux recents sur la preparation de ceramiques dielectriques pour condensateurs. On analyse la stabilite de la structure perovskites et les conditions de formation des phases pyrochlore

Stabilization of the perovskite phase and dielectric properties of ceramics in the Pb(Zn1/3Nb2/3)O3-BaTiO3 system

Abstract: L'addition de BaTiO 3 permet d'eviter la formation de phase pyrochlore dans les ceramiques de PZN. On etudie la preparation, les relations de phases et les proprietes dielectriques de plusieurs compositions du systeme binaire PZN-BT

SI3N4-SiC composites

Abstract: On etudie les effets de particules et de trichites de SiC sur la tenacite et la resistance de composites a base de Si 3 N 4

Pressure filtration: consolidation kinetics and mechanics

Abstract: Etude de la cinetique et du mecanisme de la filtration sous pression de bouillies de Al 2 O 3 et de Al 2 O 3 /ZrO 2

Sintered Al2O3-SiC-whisker composites

Abstract: Etude du frittage sans pression et des proprietes mecaniques de composites d'alumine renforces par des trichites de SiC

Microwave dielectric properties of (Ba,Sr)O-Sm2O3-TiO2

Abstract: Preparation des echantillons, methodes de mesure, resultats, discussion sur les systemes dielectriques 0,15-0,17(Ba,Sr)O•0,13-0,15Sm 2 O 3 •0,7TiO 2 ceramics

Microstructure and material properties of SiC-TiB/sub 2/ particulate composites

Abstract: The effects of TiB/sub 2/ addition to ..cap alpha..-SiC on mechanical, thermal, and electrical behavior were determined. The reliability of ceramics for structural applications is, in general, limited by variability in mechanical strength and low toughness. Property variability is normally attributed to processing- or microstructure-related flaws. Examples of microstructural flaws are exaggerated grain growth, voids and inclusions, while processing-related flaws can include impurities and nonuniform sintered material densification. These flaws can exert significant influence on nominal mechanical properties and their associated time-dependent behavior.

Dielectric materials for base-metal multilayer ceramic capacitors

Abstract: On etudie les effets dopants de SrO, CaO, MgO, Nb 2 O 5 et MnO 2 sur la resistivite de ceramiques de BaTiO 3 frittees sous faible pression partielle d'oxygene. On etudie aussi l'effet de ce frittage sur les proprietes dielectriques. On etudie les possibilites d'emploi des dielectriques developpes dans les condensateurs multi-couches a electrode au nickel, qui peuvent ainsi concurrencer les condensateurs a electrode en metal precieux

Anisotropy in Piezoelectric Properties of Modified Lead Titanate Ceramics

Abstract: Note: Damjanovic, D Penn State Univ,Mat Res Lab,University Pk,Pa 16802G6809Times Cited:75Cited References Count:17 Reference LC-ARTICLE-1987-001 Record created on 2006-08-21, modified on 2017-05-10

Mechanical properties and oxidation behavior of a hot-pressed SiC-15-vol%-TiB/sub 2/ composite

Abstract: The strength, fracture toughness, and oxidation behavior of a hot-pressed SiC-TiB/sub 2/ composite (with B and C additions) were investigated. Adding 15 vol% TiB/sub 2/ to an SiC matrix increased the mean strength and mean fracture toughness of the composite by 28% and 45%, respectively. Oxidation of the SiC-15-vol%-TiB/sub 2/ composite occurred slowly at 1000C and 1200C but was catastrophic at 1400C.

Processing and mechanical properties of SiC-whisker-Al2O3-matrix composites

Abstract: Etude des proprietes mecaniques d'un composite de Al 2 O 3 renforce par 30% en volume de trichites de SiC en fonction des parametres du pressage chaud. Etude des reactions et de la microstructure interfaciales. Analyse des mecanismes de renforcement

Processing and creep performance of siC-Whisker-reinforced Al 2 O 3

Abstract: On procede par melange et dispersion des constituants, filtration sur filtre-presse et pressage chaud. Etude de la microstructure, des proprietes mecaniques et du fluage des composites obtenus

SiC-whisker-reinforced Si3N4 composites

Abstract: Fabrication de composites Si 3 N 4 /trichites de SiC par voie humide et nitruration, puis pressage isostatique chaud. Evaluation des proprietes mecaniques. La presence d'impuretes de cobalt diminue la resistance. On discute des facteurs influant sur la tenacite

Phase relations and dielectric properties of ceramics in the system Pb(Zn1/3Nb2/3)O3-SrTiO3-PbTiO3

Abstract: Etude des effets de la temperature et de la duree de calcination sur la stabilite de la structure perovskite dans le systeme PZN-ST-PT. Preparation de ceramiques exemptes de pyrochlore a constantes dielectriques elevees par optimisation des conditions de calcination et de frittage

0-3 PIEZOELECTRIC COMPOSITES PREPARED BY COPRECIPITATED PbTiO//3 POWDER.

Abstract: Preparation d'une poudre de PbTiO 3 par precipitation d'une solution aqueuse de Pb(NO 3 ) 2 , TiCl 4 et NH 4 OH. Preparation de composites flexibles par incorporation de la poudre dans un gel polymere dielectrique. Proprietes dielectriques et piezoelectriques de ces composites

Fiber-reinforced SiC composites with improved mechanical properties

Abstract: Continued development of ceramic-ceramic composites has produced SiC-reinforced SiC composites with enhanced physical and mechanical properties. Composites have been produced with exceptional strain tolerance (strain gage derived) and fracture toughness values which are significantly higher than those of nonreinforced SiC. Flexural strengths at both room temperature and at elevated temperatures also are presented.

A low temperature path to the preparation of ultrafine ferrites

Abstract: Ultrafine ferrites, {MFe_2O_4} where M = Mg, Mn, Fe, Co, Ni, and Zn, were prepd. by the combustion/decompn. in a melt of solid soln. precursors, hydrazinium metal hydrazinecarboxylate hydrates, {N_2H_5M_1}/{3Fe_2}/{3(N_2H_3COO)}3.{H_2O} (M = Mg, Mn, Fe, Co, Ni, and Zn). The precursors decomp. at low temps. (75-200°) with the evolution of large amts. of gases. Ultrafine ferrites having particle sizes 6-22 nm and surface area 100-140 {m^2}/g were obtained and characterized by x-ray powder diffraction, Moessbauer spectra, particle size anal., and surface area measurements.

Hydrothermal processing of ceramics

Abstract: Revue de travaux recents sur la preparation de poudres fines d'oxydes cristallins par reaction hydrothermale, sur le frittage reactif hydrothermal d'oxydes, sur la croissance cristalline hydrothermale de nouveaux materiaux, sur la formation de carbones spheriques par pyrolyse sous pression de copolymeres

Characterization of varistor-type raw materials prepared by the evaporative decomposition of solutions technique

Abstract: Production de poudres de ZnO dopees par CoO, MnO 2 , Bi 2 O 3 et Sb 2 O 3 par decomposition evaporative de solutions d'acetates metalliques. On etudie la morphologie des poudres obtenues

Angle-Resolved XPS Analysis of Oxidized Polycrystalline Sic Surfaces

Abstract: Etude de la composition et de l'epaisseur de la couche d'oxyde et des contaminants a la surface de SiC polycristallin

Properties and uses of synthetic emulsion polymers as binders in advanced ceramics processing

Abstract: On passe en revue le role des liants dans l'elaboration des ceramiques. On discute des proprietes des polymeres synthetiques en emulsion et on montre les utilisations de ces materiaux et leur influence sur les proprietes physico-mecaniques des ceramiques crues