MOLD COATING MATERIAL COUNTERMEASURE AGAINST CASTING DEFECT

摘要

PURPOSE:To obtain a mold coating material for countermeasure against casting defects which consists in adding good conductive metal powder of Al, Cu, etc. to an aqueous hydrochloric acid soln. of amorphous alumina and which prevents shrinkage detects such as shirnkage cavity in casting and improves production efficiency. CONSTITUTION:A titled mold coating material is a colloidal liquid prepd. by adding and mixing a suitable amount of good conductive metal powder of Al, Cu, Fe, etc. to an aqueous hydrochloric acid soln. of amorphous alumina. If this coating material 2 is applied on the side wall of a mold (b) which is at a position between the mold (a) and mold (b) where shrinkage cavity of molten metal 1 is liable to occur at the time of casting by using a metal such as Al alloy, the molten metal in this position is quickly cooled, thus the rate of shrinkage defects sich as shrinkage cavity decreases extremely, and this results in improved production efficiency and decreased costs.