| 摘要 |
PURPOSE:To improve the collapsing property of a casting mold and to enhance the strength thereof so that the mold withstands the pressure of a molten metal at the time of casting a nonferrous alloy by using the casting mold consisting of a refractory slurry contg. a specific silica concn. of a refractory binder and specific ratio of silica sand. CONSTITUTION:The casting mold is produced by using the refractory slurry contg. the refractory binder having 10-18wt.% silica concn. and 30-60wt.% silica sand for the casting mold to be used for casting of an aluminum alloy, etc. The strength of the mold is considerably lowered and the stability of the slurry is degraded if the silica concn. in the refractory binder is <10wt.%. The collapsing property is poor if the silica concn. exceeds 18wt.%. The effect of the addition is low and the improvement in the collapsing property is not attained if the compounding ratio of the silica sand in the refractory power is <=30wt.%. The strength of the mold is considerably lowered and the mold is cracked at the time of casting of the ratio exceeds 60wt.%.
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