摘要 |
1. Stabilised or unstabilised zirconium dioxide powder and a process for its preparation. 2.1 In the previously practised processes for the preparation of zirconium dioxide powder, the use of aqueous solutions and the removal of precipitates are great disadvantages. Moreover, the process products often do not have the desired flow, compacting and sintering properties as a result of inhomogeneous distribution of the stabiliser and the presence of large crystallites and hard agglomerates. 2.2 By dissolving zirconyl chloride and, if desired, a stabiliser or its precursor in concentrated formic acid at elevated temperature, evaporating the solution to dryness by evaporation of water, hydrogen chloride and formic acid, calcining of the residue at elevated temperature and, if desired, grinding of the calcined product, it is possible to prepare a stabilised or unstabilised zirconium dioxide powder having good properties. 2.3 The stabilised or unstabilised zirconium oxide powder is suitable for the preparation of sintered articles which can be exposed to high mechanical and/or thermal stresses or are intended to be used for optical purposes. |