| 摘要 |
PURPOSE:To prevent the occurrence of failure by impregnating an organic solvent having a property to dissolve an organic binder on a porous sand and by degreasing a molded body placed on the sand. CONSTITUTION:A binder mixed body is made by kneading a metallic powder such as SUS 316 with the organic binder made of PS, acrylic resin, wax and stearic acid or the like in prescribed weight ratio and the molded body 1 is formed from the binder mixed body by injection molding or the like. On the other hand the sand 2 such as porous Al2O3 powder is impregnated with the organic solvent such as dichloromethane having the property to dissolve the binder and the excess organic solvent is removed to make the sand 2 in wet state. The molded body 1 placed on the sand 2 is heated to a prescribed temp. in an atmospheric pressure and in air and is cooled naturally after kept at the temp. for several hours and the binder of the molded body 1 is gradually dissolved from the surface with evaporation of the organic solvent to generate fine pores on the surface of the molded body 1. Furthermore, the binder is vaporized by heating to a prescribed temp. and is discharged from the fine pores to obtain a degreased body free from foaming, deformation or the like. |
