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AssigneeNGK Insulators, Ltd.
InventorsNaomi Teratani, Toru Hayase, Yuji Katsuda, Masahiro Kida
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A method for manufacturing an alumina sintered body of the present invention comprises: (a) forming a mixed powder containing at least Al2O3 and MgF2 or a mixed powder containing Al2O3, MgF2, and MgO into a compact having a predetermined shape; and (b) performing hot-press sintering of the compact in a vacuum atmosphere or a non-oxidizing atmosphere to form an alumina sintered body, in which when a amount of MgF2 to 100 parts by weight of Al2O3 is represented by X (parts by weight), and a hot-press sintering temperature is represented by Y (° C.), the hot-press sintering temperature is set to satisfy the following equations (1) to (4) 1,120≦Y≦1,300 (1) 0.15≦X≦1.89 (2) Y≦−78.7X+1,349 (3) Y≧−200X+1,212 (4).
A method for manufacturing an alumina sintered body comprising the steps of:
An alumina sintered body comprising magnesium and fluorine, in which a constituent crystalline phase is composed of only Al2O3, or as at least one constituent phase other than that of alumina, MgF2 or MgF2 and MgAl2O4 are contained, wherein an open porosity is less than 0.1%, the bulk density is 3.95 g/cm3 or more, and a volume resistivity calculated from a current value 1 minute after application of 2 kV/mm at room temperature is 1×1014 Ω·cm or more.
Dependencies are inferred from the claim text.