Heat conductive colored aluminum nitride sintered body and method of

Abstract

A heat conductive aluminum nitride sintered body contains 100 parts by weight of aluminum nitride, at least 0.005 parts by weight and not more than 0.5 parts by weight of carbon, at least 0.01 parts by weight and not more than 15 parts by weight of a rare earth aluminum oxide in terms of the simple substance of a rare earth element, and at least 0.01 parts by weight and not more than 15 parts by weight of at least one element selected from a group of compounds containing elements belonging to the groups IVB, VB and VIB of the periodic table in terms of the simple substance of the element. Heat conductivity of the aluminum nitride sintered body is at least 100 W/m.multidot.K and not more than 270 W/m.multidot.K at the ordinary temperature. According to a method of preparing such an aluminum nitride sintered body, at least 0.01 parts by weight and not more than 5 parts by weight of carbon, at least 0.01 parts by weight and not more than 15 parts by weight of an oxide of a rare earth element, and at least 0.01 parts by weight and not more than 15 parts by weight of an oxide, a carbide or a nitride of an element belonging to the group IVB, VB or VIB of the periodic table are added to 100 parts by weight of aluminum nitride. A compact of this mixture is fired in a nonoxidizing atmosphere under a temperature of at least 1500.degree. C. and not more than 2100.degree. C.