Zirconia stabilized with a mixture of the rare earth oxides

✍ Scribed by W. Pyda; K. Haberko; Z. Żurek

• Publisher: Elsevier Science
• Year: 1992
• Tongue: English
• Weight: 603 KB
• Volume: 10
• Category: Article
• ISSN: 0955-2219
• DOI: 10.1016/0955-2219(92)90020-e

✦ Synopsis

A hydrothermal technique was used to prepare micropowders of ZrO 2 solid solutions stabilized by the mixture of rare earth oxides and yttria (Ln203) recovered from phosphogypsum. Phase compositions and particle sizes of the powders were measured. Zirconia solid solutions of cubic and tetragonal symmetry are the major phases. A larger Ln203 concentration promotes a greater cubic phase content. Powders having low Ln203 concentrations have small amounts of monoclinic phase present.

The phase composition, fracture toughness ( K1c) and Vickers hardness of samples sintered at temperatures ranging from 1250 to 1350°C were measured. Tetragonal and, in some cases, monoclinic zirconia solid solutions are found in the microstructure of the sintered bodies. Two ordered phases with the jormulae Ln2Zr20 v and Ce2Zr301o were also detected in the system. Tetragonal zirconia polycrystals ( TZP) with high (10 MPa m °" s) .fracture toughness were found.