| 摘要 |
<p>An aluminum nitride sintered body containing 1 to 10 % by weight of an oxide of at least one element selected from a group consisting of a group IIIa element, Ca, Sr and Ba, the concentration of a Si component in the sintered body is 0.01 to 0.2 % by weight and three-point bending strength is 490 MPa or more. The sintered body is characterized in that a crystal structure composed of aluminum nitride crystal grains is formed, the fracture toughness is 2.8 MN/m<3/2> or more, the three-point bending strength is 490 MPa or more and the thermal conductivity is 150 W/m.k or more. In the crystal structure, the distribution of the crystal grain distribution is adequately adjusted. The growth of the AlN sintered body is restricted, thus the structure of the sintered body is fined, and the distribution of the crystal grain size is controlled adequately so that the strength and the fracture toughness of the sintered body are improved. Moreover, the mechanical strength and fracture toughness are improved without impairing the heat radiating characteristics of the aluminum nitride.</p> |
