Toto Ltd.

Shogo Shimada

Akio Matsumoto

Takayuki Ide

Atsushi Teramoto

Yasutaka Ushijima

Kazuki Amano

There is provided a semiconductive ceramic sintered compact that has a conductivity high enough to attain static electricity removal and antistatic purposes and, at the same time, has excellent mechanical properties or stability over time. The semiconductive ceramic sintered compact includes at least a main phase and first and second phases contained in the main phase observed as a result of observation of any face of the sintered compact, the main phase being a ceramic sintered phase containing AlOparticles, the first phase being a grain boundary phase including a conductive substance-containing conductive phase and AlOparticles, the AlOparticles being present in an island-sea form in the conductive phase, the second phase being a grain boundary phase containing a conductive phase having the same composition as the conductive phase in the first phase and having a structure that electrically connects the first phases three-dimensionally to each other.

Semiconductive ceramic sintered compact

There is provided a semiconductive ceramic sintered compact that has a conductivity high enough to attain static electricity removal and antistatic purposes and, at the same time, has excellent mechanical properties or stability over time. The semiconductive ceramic sintered compact includes a main phase and a conductive phase, wherein the main phase is a ceramic sintered phase including AlOparticles, the area ratio of the conductive phase to the main phase is 0% (exclusive) to 10% (inclusive), and the conductive phase includes two or more metals selected from Mn (manganese), Fe (iron), and Ti (titanium) and has a composition meeting a relation of Mn/(Ti+Mn+Fe)&#x3e;0.08 or Mn/Ti&#x3e;0.15.

A composite material according to the invention includes X parts by volume of boron carbide, Y parts by volume of silicon carbide, and Z parts by volume of silicon as main components, wherein 10&#x3c;X&#x3c;60, 20&#x3c;Y&#x3c;70, and 5&#x3c;Z&#x3c;30 are satisfied, and grains of 10 &#x3bc;m or more of the boron carbide and the silicon carbide are 10-50 parts by volume.

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Fukuoka, Japan

Shogo Shimada