Phase transformation and microstructure development of in situ toughened Yb alpha-SiAlON ceramics prepared by two-step hot-pressing


In this paper in situ toughened Yb alpha-SiAlON ceramics with elongated grains were prepared by two-step hot-pressing. The phase transformation and microstructure development of the samples during the two-step sintering were discussed in detail. It was found that at low temperatures, the formation of intermediate phases reduced the amount of liquid phase and thus slowed down the dissolution and mass transportation processes. In this way, the grain growth was depressed and fine grains were obtained. At the elevated temperature, the intermediate phases would be dissolved, resulting in abundant liquid phase and fast anisotropic grain growth. By the two-step sintering procedure, the nucleation and grain growth could be well manipulated and coarse elongated grains could be produced. These elongated grains improved the fracture toughness of the sintered ceramics via the mechanisms such as grain pull-out and debonding, which were clearly observed by SEM. In addition, the preferred orientation of the elongated a-SiAlON grains was also studied in the light of their growth habit. (c) 2005 Elsevier B.V. All rights reserved.




Materials Science


Liu, GH; Chen, KX; Zhou, HP; Ren, KG; Ning, XS; Pereira, C; Ferreira, JMF

nossos autores

Partilhe este projeto

Publicações similares

Usamos cookies para atividades de marketing e para lhe oferecer uma melhor experiência de navegação. Ao clicar em “Aceitar Cookies” você concorda com nossa política de cookies. Leia sobre como usamos cookies clicando em "Política de Privacidade e Cookies".