Precision casting mold and method of producing the same

Abstract

Provided is a precision casting mold including a core and an outer mold, and the outer mold is made up of: a prime layer which is formed from a slurry film obtained by drying slurry for the precision casting mold including a silica sol having a particle size of 20 nm; and a multi-layered backup layer which is formed on the outside of the prime layer by repeatedly forming a first backup layer obtained by forming and drying a slurry layer formed from the slurry for the precision casting mold and a stucco layer in which stucco particles as a stucco material having particle size distribution, in which a mixing ratio of the fine particles having a particle size of 50 to 500 μm is 1; the mixing ratio of the medium particles having a particle size of 0.5 to 2 mm is 1 to 16; and the mixing ratio of the coarse particles having a particle size of 2 to 4 mm is 1 to 40, is adhered to the slurry layer.

1 . A precision casting mold which is used to produce a cast product, comprising:
 a core having a shape corresponding to an internal hollow portion of the cast product; and   an outer mold corresponding to a shape of an outer peripheral surface of the cast product,   wherein the outer mold is made up of: a prime layer which is formed on an inner peripheral surface and is formed from a slurry film obtained by drying slurry for the precision casting mold; and a multi-layered backup layer which is formed on the outside of the prime layer by repeatedly forming a backup layer obtained by forming and drying a slurry layer formed from the slurry for the precision casting mold and a stucco layer in which stucco particles as a stucco material having particle size distribution, in which a mixing ratio of fine particles having a particle size of 50 to 500 μm is 1; the mixing ratio of medium particles having a particle size of 0.5 to 2 mm is 1 to 16; and the mixing ratio of coarse particles having a particle size of 2 to 4 mm is 1 to 40, are adhered to the slurry layer.   
     
     
         2 . The precision casting mold according to  claim 1 , wherein the prime layer has a stucco layer in which stucco particles as a stucco material having particle size distribution, in which a mixing ratio of fine particles having a particle size of 50 to 500 μm is 1; a mixing ratio of medium particles having a particle size of 0.5 to 2 mm is 1 to 16; and a mixing ratio of coarse particles having a particle size of 2 to 4 mm is 1 to 40, are adhered to the slurry layer formed from the slurry for the precision casting mold. 
     
     
         3 . A method of producing a precision casting mold which is used to produce a cast product, the method comprising:
 a first film forming process in which a precision casting wax pattern is immersed and pulled up into/from slurry for the precision casting mold and then a drying treatment is performed, thereby forming a prime layer, which is formed from a slurry film, on a surface of the wax pattern;   a second film forming process in which stucco particles as a stucco material having particle size distribution, in which a mixing ratio of fine particles having a particle size of 50 to 500 μm is 1; a mixing ratio of medium particles having a particle size of 0.5 to 2 mm is 1 to 16; and a mixing ratio of coarse particles having a particle size of 2 to 4 mm is 1 to 40, is sprinkled on a surface of the slurry after the wax pattern formed with the prime layer is immersed and pulled up into/from the slurry for the precision casting mold and then a drying treatment is performed, thereby forming a backup layer;   a molded body forming process in which the second film forming process of forming the backup layer is repeated more than once, thereby obtaining a molded body formed with a multi-layered backup layer;   a wax removing process in which wax of the wax pattern is melted and removed from the obtained molded body; and   a mold firing process in which the molded body obtained after the wax removal is subjected to a firing treatment, thereby obtaining a mold.   
     
     
         4 . The method of producing the precision casting mold according to  claim 3 , wherein the stucco particles as a stucco material having particle size distribution, in which a mixing ratio of fine particles having a particle size of 50 to 500 μm is 1; a mixing ratio of medium particles having a particle size of 0.5 to 2 mm is 1 to 16; and a mixing ratio of coarse particles having a particle size of 2 to 4 mm is 1 to 40, is adhered to the slurry layer formed from the slurry for the precision casting mold to form a stucco layer and the stucco layer is dried during the first film forming process.