Patent ID: 8376318

Claim:
A powder including, in percentages by weight, based on oxides of: (a) more than 92% of zirconia particles, said powder comprising: (a1) more than 60% of zirconia particles having a size larger than 50 microns, called zirconia aggregate particles, wherein at least 90 wt. % of said zirconia aggregate particles containing less than 50 wt. % of monoclinic phase; (a2) more than 15% of zirconia particles having a size smaller than 50 μm, called matrix particles of zirconia; (b) 1% to 2% of silica particles having a size smaller than 50 microns, called fine silica particles; (c) 0.3% to 5% of particles consisting of one, two or three oxides selected from the group consisting of CaO, MgO and Y 2 O 3 called additional oxide particles, wherein at least 55 wt. % of said additional particles have a size smaller than 50 μm; and (d) less than 1% of particles consisting of other oxides; said powder also being such that it comprises: more than 5% of zirconia aggregate particles which size is larger than 1 mm; and from 8% to 20% of matrix particles of zirconia having a size smaller than 15 μm and comprising, to more than 95% of their mass, a monoclinic phase, called matrix particles of monoclinic zirconia.