JPS6428273A - Production of high-purity magnesium oxide sintered compact - Google Patents

Abstract

PURPOSE:To produce a dense and high-purity MgO sintered compact at relatively low burning temperature, by adding a fluoride or chloride to a metal oxide or metal hydroxide, calcining the blend, burying MgO moldings into the resultant calcined powder and burning the composite. CONSTITUTION:A fluoride (e.g. MgF2, AlF3, etc.) or chloride (e.g. MgCl2 or AlCl3) is added to a metal oxide (e.g. MgO, Al2O3) or metal hydroxide [e.g. Mg(OH)2, Al(OH)3] and the blend is calcined at decomposition temperature or below of the above-mentioned additives. MgO moldings are buried in the resultant calcined powder and the composite is burned. The fluoride or chloride contained in calcined powder is decomposed at high temperature during burning to keep surroundings of moldings to be burned to fluorine atmosphere or chlorine atmosphere and promote sintering of the MgO moldings. Consequently, dense and high-purity MgO sintered compact can be obtained by relatively low burning temperature. Since such additives as left as impurity are not added, lowering of the purity does not occur and a special equipment or operation such as hot press is also unnecessary.