Influence of the oxygen pressure on the chemical state of yttrium in polycrystalline α-alumina. Relation with microstructure and mechanical toughness

✍ Scribed by M.K. Loudjani; C. Haut

• Publisher: Elsevier Science
• Year: 1996
• Tongue: English
• Weight: 792 KB
• Volume: 16
• Category: Article
• ISSN: 0955-2219
• DOI: 10.1016/0955-2219(96)00031-3

✦ Synopsis

The influence of yttrium on the microstructure and toughness of a-alumina is studied as a function of oxygen partial pressure and chemical state of the doping element. For doping amounts higher than 0.03 mol% of Y,O,, Y,AI,O,, garnet precipitates and the alumina grain size is then limited by such a precipitation along grain boundaries. For doping amounts lower than or equal to 0.03 mole/o of Y,O,, yttrium ions are in solid solution as defect complexes of the type (2 Y-i, + m VG + nOJWW

. and segregates along grain boundaries.