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US 10,703,677 B2Granted
SiC sintered body, heater and method for producing SiC sintered body
AssigneeSumitomo Osaka Cement Co., Ltd.
InventorsMegumi Ootomo, Hiroaki Nagatomo, Kentaro Takahashi
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Abstract
Provided is a SiC sintered body which contains nitrogen atoms, wherein a ratio Rmax/Rave of a maximum volume resistivity Rmax of the sintered body to an average volume resistivity Rave of the sintered body is 1.5 or lower; a ratio Rmin/Rave of a minimum volume resistivity Rmin of the sintered body to the average volume resistivity Rave is 0.7 or higher; and a relative density of the sintered body is 98% or higher.
Claims9
A SiC sintered body which contains nitrogen atoms,
- wherein a ratio Rmax/Rave of a maximum volume resistivity Rmax of the SiC sintered body to an average volume resistivity Rave of the SiC sintered body is 1.5 or lower;
- a ratio Rmin/Rave of a minimum volume resistivity Rmin of the SiC sintered body to the average volume resistivity Rave is 0.7 or higher;
- and
- a relative density of the SiC sintered body is 98% or higher,
- the volume resistivity of the SiC sintered body is s a value obtained by measuring the SiC sintered body by a four-probe measurement method,
- the average volume resistivity of the SiC sintered body is an average value of five measured values obtained for any five places in a plane of the SiC sintered body,
- the maximum volume resistivity of the SiC sintered body is a maximum value among the five measured values,
- the minimum volume resistivity of the SiC sintered body is the minimum value among the five measured values, and
- a content of the nitrogen atoms in the SiC sintered body is 40 to 5000 ppm.
6 more elements
A method for producing a SiC sintered body, comprising:
- a step of mixing
- at least one SiC powder having an average particle diameter of 0.1 μm or higher and 1.0 μm or lower and selected from the group consisting of α-SiC powder and β-SiC powder,
- a SiC ultrafine powder having an average particle diameter of lower than 0.1 μm and synthesized in a gas phase by plasma CVD, and
- Si3N4 particles having an average particle diameter of 0.1 μm or higher and 2.0 μm or lower;
- and
- a step of sintering a mixture obtained in the step of mixing,
- wherein, in the step of mixing, the SiC ultrafine powder is mixed in an amount of more than 2 parts by mass and less than 20 parts by mass with respect to 100 parts by mass of the SiC powder, and
- the Si3N4 particles are mixed in an amount of 0.05 parts by mass or more and 3 parts by mass or less with respect to 100 parts by mass of the SiC powder, and
- in the step of sintering, the mixture is sintered at a temperature of 2200° C. or higher and lower than 2400° C.
6 more elements
Dependencies are inferred from the claim text.