Grain Size Reduction and Surface Modification Effect in Polycrystalline Y2O3 Subject to High Pressure Processing

• Published in: Ceramic Engineering and Science Proceedings pp. 157 - 164
• Main Authors: Al‐Sharab, Jafar F, Kear, Bernard H, Deutsch, S, Tse, Stephen D
• Format: Book Chapter Journal Article
• Language: English
• Published: Hoboken, NJ, USA John Wiley & Sons, Inc 01.01.2011
• Subjects: Ceramics; Densification; Grain size; high pressure processing; high temperature processing; micro‐grained; Nanocomposites; Nanomaterials; Nanostructure; nanostructured oxide ceramics; Oxides; polycrystalline; Yttrium oxide
• ISBN: 9781118059920; 1118059921
• ISSN: 0196-6219
• DOI: 10.1002/9781118095362.ch15

Over the past decade, there has been growing interest in the fabrication of nanostructured oxide ceramics for diverse structural and functional applications. Typically, a nanostructured oxide is fabricated by pressure- or field-assisted sintering of a nanopowder compact. Even so, it is difficult to achieve complete densification without causing significant grain growth. A reversible-phase-transformation mechanism to convert full dense polycrystalline Y2O3 directly into the nanocrystalline state under high pressure and high temperature processing conditions (8 GPa/1000 C) is described. A surface modification effect and superplastic compressive phenomena observed in polycrystalline Y2O3 processed at high temperature/pressure conditions are also reported.