| 摘要 |
PROBLEM TO BE SOLVED: To provide an alumina sintered compact having a low content of <100 ppm impurity elements except aluminum and extremely few pores. SOLUTION: This method for producing an alumina sintered compact having <=10 μm maximum diameter of pore, <=20 pores/1 mm2 number of pores having 1 μm-10 μm maximum diameter existing in a unit area and <100 ppm content of impurity elements except aluminum comprises molding alumina powder which has substantially no fracture and is composed of a primary particle of polyhedron and in which when the maximum particle diameter parallel to a hexagonal lattice plane of α-alumina of hexagonal closed-packed lattice is D and a particle diameter perpendicular to the hexagonal closed-packed plane is H, the alumina powder is composed of α alumina particles having >=0.5 and <=3.0 ratio of D/H, 0.01 μm to 1.0 μm number-average particle diameter of the α alumina particles and a particle size distribution of <=10 ratio of D90/D10 when particle diameters at 10% accumulation and at 90% accumulation from the fine particle side are D10 and D90, respectively and >=99.99% purity and sintering the molding product in the atmosphere at 1,500 deg.C to 1,800 deg.C. |
