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(Referência obtida automaticamente do Web of Science, por meio da informação sobre o financiamento pela FAPESP e o número do processo correspondente, incluída na publicação pelos autores.)

Internal Residual Stresses in Partially Crystallized Photo-Thermo-Refractive Glass

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Autor(es):
Serbena, Francisco C. [1] ; Souza, Guilherme P. [2] ; Zanotto, Edgar D. [2] ; Lumeau, Julien [3] ; Glebova, Larissa [3] ; Glebov, Leon B. [3]
Número total de Autores: 6
Afiliação do(s) autor(es):
[1] State Univ Ponta Grossa UEPG, Dept Phys, BR-84030900 Ponta Grossa, PR - Brazil
[2] Fed Univ Sao Carlos UFSCar, Dept Mat Engn DEMa, Vitreous Mat Lab LaMaV, BR-13565905 Sao Carlos, SP - Brazil
[3] Univ Cent Florida, Coll Opt & Photon, CREOL, Orlando, FL 32816 - USA
Número total de Afiliações: 3
Tipo de documento: Artigo Científico
Fonte: Journal of the American Ceramic Society; v. 94, n. 3, p. 671-674, MAR 2011.
Citações Web of Science: 11
Resumo

Photo-thermo-refractive glass containing nanosized NaF crystals embedded in the glassy matrix shows a significant shift of X-ray diffraction (XRD) lines to lower angles resulting from large residual (tensile) stresses within the crystals. This is thus an excellent ``model{''} system to test residual stresses models in glass-ceramics and composites because: the estimated stresses are high-about 1 GPa-the precipitates are nearly spherical, the NaF crystals structure is cubic and their volume fraction is quite small, which eliminates overlap between the stress fields of neighbor crystals. Samples treated at a sufficiently high temperature to develop larger (micrometer size) crystals revealed microcracking of the glassy matrix around the crystals, which partially relieved the residual stresses and decreased the shift of the XRD peaks. The experimental results for the magnitude of the residual stresses and the critical crystal diameter for microcracking agree with theoretical values calculated by the Selsing and the Davidge \& Green models, respectively. These results suggest that these two models can be used for stress estimates and as a first approach for the design of tough glass-ceramics. (AU)

Processo FAPESP: 07/08179-9 - Processos cinéticos em vidros e vitrocerâmicas
Beneficiário:Edgar Dutra Zanotto
Linha de fomento: Auxílio à Pesquisa - Temático