Niobia and tantala codoped orthorhombic zirconia ceramics
- Johannes Kepler Univ., Linz (Austria). Inst. fuer Chemische Technologie Anorganischer Stoffe
During recent studies it was found that codoping of zirconia with niobia and tantala yielded very corrosion resistant, orthorhombic zirconia ceramics. The powders for those novel ceramics were made via the sol-gel technique by hydrolysis of the respective metal propoxides; a method which required dry-box techniques during the preparation of the alkoxides. In these studies the authors investigated the fabrication of precursor material from aqueous solutions. The preparation of aqueous solutions of salts of zirconium, niobium and tantalum is hampered by rapid hydrolysis. Premature hydrolysis of the chlorides and oxichlorides of niobium, tantalum and zirconium can be, however, prevented in aqueous solutions of oxalic acid. Thus the authors investigated the coprecipitation of hydroxides as precursors by reacting oxalic acid solutions of the respective cations with aqueous ammonia. In addition they studied the effects of calcination and of hydrothermal conversion of the hydroxides to oxides on the powder characteristics and on the mechanical properties of the niobia and tantala codoped zirconia ceramics.
- OSTI ID:
- 55435
- Journal Information:
- Scripta Metallurgica et Materialia, Vol. 32, Issue 8; Other Information: PBD: 15 Apr 1995
- Country of Publication:
- United States
- Language:
- English
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