%0 Journal Article
%@holdercode {isadg {BR SPINPE} ibi 8JMKD3MGPCW/3DT298S}
%@nexthigherunit 8JMKD3MGPCW/3ESR3H2
%@secondarymark B3_ASTRONOMIA_/_FÍSICA B2_BIOTECNOLOGIA B2_CIÊNCIAS_BIOLÓGICAS_II A1_ENGENHARIAS_I A1_ENGENHARIAS_II A2_ENGENHARIAS_III B1_ENGENHARIAS_IV A1_INTERDISCIPLINAR A1_MATERIAIS B1_MEDICINA_I B1_MEDICINA_II A2_ODONTOLOGIA B2_QUÍMICA
%3 compressive creep.pdf
%@mirrorrepository sid.inpe.br/mtc-m19@80/2009/08.21.17.02.53
%D 2010
%4 sid.inpe.br/mtc-m19@80/2010/06.01.13.49
%T Compressive creep of hot pressed silicon carbide
%@usergroup administrator
%@usergroup banon
%@usergroup marciana
%@usergroup simone
%V 527
%@affiliation Universidade de Brasília (UnB)
%@affiliation Instituto Nacional de Pesquisas Espaciais (INPE)
%@affiliation Instituto de Aeronáutica e Espaço (IAE)
%@versiontype publisher
%X Silicon carbide has a good match of chemical, mechanical and thermal properties and therefore is considered an excellent structural ceramic for high temperature applications. The aim of the present work is compressive creep evaluation of liquid phase sintered silicon carbide with aluminum and rare earth oxide as sintering aids. Rare earth oxides are possible additives considering their highly refractory remnant grain-boundary phase and lower synthesis costs compared to high purity rare earth. Samples were prepared with silicon carbide powder (90 wt%) and aluminum oxide (5 wt%) plus rare earth oxide (5 wt%) additions. Powders were mixed, milled and hot pressed at 1800 °C in argon atmosphere. Compressive creep tests were carried out under stress from 150 to 300 MPa and temperatures from 1300 to 1400 °C. At lower creep test temperatures, the obtained stress exponent values were correlated to mechanisms based on diffusion. At intermediate temperatures, grain-boundary sliding becomes operative, accommodated by diffusion. At higher temperatures cavities are discernible. Oxidation reactions and ionic diffusion result on surface oxidized layer, grain-boundary amorphous and intergranular crystalline Al6Si2O13, ä-Y2Si2O7 and YAG phases. In this case cavitation and amorphous phases redistribution enhance grain-boundary sliding, not accommodated by diffusion. Coalescence occurs at triple point and multigrain-junctions, with subsequent strain rate acceleration and cavitational creep.
%8 July
%@area FISMAT
%@secondarykey INPE--PRE/
%@documentstage not transferred
%K Rare earth additions - Aluminum  -  Argon  -  Coalescence  -  Creep  -  Diffusion  -  Grain boundary sliding  -  High temperature applications  -  Mechanical properties  -  Microstructure  -  Rare earths   -  Silicon carbide  -  Sintered carbides  -  Sintering  -  Strain rate  -  Thermodynamic properties.
%@archivingpolicy denypublisher denyfinaldraft24
%@doi 10.1016/j.msea.2010.04.044
%@issn 0921-5093
%@group LAS-CTE-INPE-MCT-BR
%N 18-19
%@dissemination WEBSCI; PORTALCAPES.
%P 4891-4896
%A Silva, C. R. M.,
%A Nono, Maria do Carmo Andrade,
%A Hwang, M. K.,
%B Materials Science and Engineering A
%2 sid.inpe.br/mtc-m19@80/2010/06.01.13.49.25
%@secondarytype PRE PI