| 摘要 |
PURPOSE:To obtain easily sinterable alumina by forming a spinel layer on the surface of alumina particles. CONSTITUTION:This easily sinterable alumina consists essentially of alumina having a 0.07-1.05wt.% spinel layer on its surface. This alumina is obtd. by the following method. Namely, aluminum hydroxide and/or intermediate alumina is wetted with a spinel-forming soln. consisting of hydrochloric acid and/or aluminum chloride and water-soluble magnesium salt which can be dissolved in acid to deposit 0.02-0.3wt.% magnesium salt in terms of MgO. Then the treated alumina is put in a chamotte vessel and fired at 1000-1400 deg.C. After firing, the alumina is treated with a diluted acid soln. Thus, the obtd. slurry can maintain good fluidity and realizes easy forming process and a high-density sintered compact. By treating the material with a diluted basic soln. after firing, radioactive elements can be removed so that the obtd. material does not cause malfunctioning due to alpha-ray when applied for IC substrates. |
