| 摘要 |
PURPOSE:To inexpensively prepare the title sintered body which can be calcined at lower temp. than conventional calcination temp., and having superior sinterability and causing hardly deterioration of strength even at high temp. by calcining a mixture consisting of of mullite powder and a small amt. of MgO, then heat-treating in a specified temp. range. CONSTITUTION:After calcining a uniform mixture consisting of 95-99.8wt.% mullite powder as raw material composed of 65:35-80:20 proportion by weight of alumina to silica, or mullite powder prepd. by calcining and pulverizing the raw mullite powder, with 0.2-5wt.% MgO powder or a salt [e.g., MgCO3, Mg(OH)2, etc.] contg. 0.2-5wt.% MgO, or an org. compd. (e.g., magnesium methoxide, etc.), the calcined product is heat-treated at 1200-1500 deg.C for 10min-100 hr, to obtain thus sintered body of mullite. By the above-described method, calcination is performed at a temp. by 150-200 deg.C lower than conventional calcination temp., and a sintered body of mullite causing scarcely deterioration of strength at room temp. and suitable as industrial material is obtd. inexpensively. |
