PRODUCTION OF ALUMINA MOLD FOR PRECISION CASTING

摘要

PURPOSE:To provide the improvement of the hot strength, etc. of a casting mold by suspending alumina powder and diiron trioxide of specific wt% thereof to a colloidal silica to form a slurry then using the slurry for the casting mold. CONSTITUTION:The alumina powder and the diiron trioxide powder of 0.1-4% thereof are suspended in the colloidal silica to form the slurry. The casting mold is then molded by using such slurry. The mold is heated to 1,500 deg.C, etc. and is held at said temp. for 10min. Mullite is formed in the casting mold by the effect of the diiron trioxide added thereto and the hot strength of the casting mold is remarkably improved. Since the reduction of the wall thickness of the casting mold is made possible, the heat control after casting is made easier and the yield of the product is improved as well.