Sand for casting mold, manufacturing method for sand casting-mold, and core for metal casting

#The present invention relates to sand for a casting mold, a manufacturing method for a sand casting mold, and a core for metal casting.

#Conventionally, binders are added to sand for casting molds for the purpose of improving shape retention properties and the like.

#For example, as a material for a casting mold, a molding material mixture for production of casting molds for metalworking has been disclosed, which includes: at least a refractory molding matrix; a binder containing waterglass; a fixed proportion of a particulate metal oxide selected from the group consisting of silicon dioxide, aluminum oxide, titanium oxide, and zinc oxide; and a carbohydrate (see, for example, Japanese National-Phase Publication (JP-A) No. 2010-506730).

#FIG. 1 shows a schematic enlarged view of an internal portion of a sand casting-mold before pouring a molten metal.

#FIG. 2 shows a schematic enlarged view of an internal portion of a sand casting-mold after pouring a molten metal.

#FIG. 3 shows a schematic enlarged view of an interface between a sand casting-mold before pouring a molten metal and a cavity to which the molten metal is to be poured.

#Hereinafter, an embodiment of the invention is described in detail,

#Sand for a casting mold according to the invention includes sand, a binder, and an inorganic compound particle having poor water solubility and generating at least one of water vapor or carbon dioxide gas by heat from a molten metal.

#When producing the sand for a casting mold according to the invention, the binder and the inorganic compound particle may be mixed in advance and used as an additive for a sand casting-mold to be used in mixture with the sand.