| 摘要 |
PURPOSE:To manufacture a casting mold sutable for precision casting of a large sized casting by inserting a pattern made of a foamed resin formed with a ceramic shell on the surface into a molding flask and packing sand to the circumference of said pattern then burning away the pattern and accelerating the curing of the ceramic shell to form a cavity. CONSTITUTION:The foamed resin pattern 1 having a pattern 1c, a sprue pattern 1a and a riser pattern 1b is manufactured of a foamed PST resin. A slurry 2 contg. a refractory binder such as silicate is sprayed by a sprayer 3 over the entire surface of the pattern 1 except the top surface of the pattern 1a and the top surface of the pattern 1b to form a slurry film 4 on the surface of the pattern 1. Dried Zr powder 5 is then sprayed by a sprayer 6 onto the film 4 to form the ceramic shell layer and further the spraying of the slurry 2 and the Zr powder 5 is alternately and repeatedly executed. The pattern 1 coated with the ceramic shell layer 7 is installed in the molding flask 8 and after the silica sand 9 is packed to the circumference thereof, the pattern is heated in a furnace to burn away the pattern 1. The casting mold of which the cavity 10 is coated with the layer 7 is thus completed. |
