Wettability of silicon carbide ceramic by Al2O3/Dy2O3 and Al2O3/Yb2O3 systems

Autor(es)

da Silva, J. A. ^[1] ; Moreschi, B. M. ^[1] ; Garcia, G. C. R. ^[1] ; Ribeiro, S. ^[1]

Afiliação do(s) autor(es)

^[1] Engn Sch Lorena EEL, Dept Mat Engn DEMAR, BR-12608970 Lorena, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: JOURNAL OF RARE EARTHS; v. 31, n. 6, p. 634-638, JUN 2013.
• Citações Web of Science: 2

Resumo

Wettability is an important phenomenon in the liquid phase sintering of silicon carbide (SiC) ceramics. This work involved a study of the wetting of SiC ceramics by two oxide systems, Al2O3/Dy2O3 and Al2O3/Yb2O3, which have so far not been studied for application in the sintering of SiC ceramics. Five mixtures of each system were prepared, with different compositions close to their respective eutectic ones. Samples of the mixtures were pressed into cylindrical specimens, which were placed on a SiC plate and subjected to temperatures above their melting points using a graphite resistance furnace. The behavior of the melted mixtures on the SiC plate was observed by means of an imaging system using a CCD camera and the sessile drop method was employed to determine the contact angle, the parameter that measures the degree of wettability. The results of variation in the contact angle as a function of temperature were plotted in graphic form which showed that the curves displayed a fast decline and good spreading. All the samples of the two systems presented final contact angles of 40 degrees to 10 degrees indicating their good wetting on SiC in the argon atmosphere. The melted/solidified area and interface between SiC and melted/solidified phase were evaluated by scanning electron microscopy (SEM) and their crystalline phases were identified by X-ray diffraction (DRX). The DRX analysis showed that Al2O3 and RE2O3 reacted and formed the Dy3Al5O12 (DyAg) and Yb3Al5O12 (YbAg) phases. The results indicated that the two systems had a promising potential as additives for the sintering of SiC ceramics. (AU)

• Processo FAPESP: 10/51925-6 - Implantação do método SEVNB para medida da tenacidade a fratura de cerâmicas de SiC sinterizadas via fase líquida com aditivos de Al2O3-Yb2O3 ou Al2O3-Nd2O3
• Beneficiário: Sebastião Ribeiro
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 12/01665-3 - Estudo da molhabilidade de cerâmicas de carbeto de silício com misturas de óxidos Yb2O3/Al2O3
• Beneficiário: Bianca Mendes Moreschi
• Modalidade de apoio: Bolsas no Brasil - Iniciação Científica
• Processo FAPESP: 12/01177-9 - Estudo da molhabilidade de cerâmicas de carbeto de silício com misturas de óxidos Al2O3-Dy2O3
• Beneficiário: Juliana Alves da Silva
• Modalidade de apoio: Bolsas no Brasil - Iniciação Científica