Zerkleinerungselemente

摘要

The invention provides the mill part comprising a sintered zirconium body meeting the following requirements: (1) a Y2O3 content of 1.0 to 4.5 mol%, (2) an average grain size of not greater than 2 mu m, (3) a bulk density of not less than 5.8 g/cm<3>, (4) a tetragonal phase zirconia content of not less than 40 volume %, (5) a toughness value of not less than 4.5 MPam<1/2>, (6) a strength value of not less than 60 kgf/mm<2>, and (7) said average grain size ( mu m), toughness (MPam<1/2>) and strength (kgf/mm<2>) values satisfying the following relation. (Average grain size)<1.4> x (Toughness)<-2.7> x (Strength)<-2.7><7>