METHOD FOR MANUFACTURING FUSIBLE CORE FOR CASTING, THE CORE, AND METHOD FOR EXTRACTING THE CORE

• Main Author: HIROKAWA KOJI
• Format: Patent
• Language: English; Korean
• Published: 01.02.2002
• Edition: 7
• Subjects: CASTING; FOUNDRY MOULDING; PERFORMING OPERATIONS; POWDER METALLURGY; TRANSPORTING

PURPOSE: A method for manufacturing a fusible core for casting, the core, and a method for extracting the core are provided to develop a technology for simply manufacturing a complicated shaped core and manufacturing a recyclable fusible core for casting to solve existing problems including frequent generation of cracks due to shrinkage and handling difficulties due to fragility. CONSTITUTION: The method for manufacturing a fusible core for casting comprises the processes of solid dissolving a salt having a higher fusion point than a temperature of a casting material into a water soluble salt having a lower fusion point than the casting material in supersaturation; and slowly solidifying the core after injecting the supersaturated solid dissolved salt material into a core mold frame so that a solidified layer having a high concentration of the salt having a higher fusion point is formed at the contour part of the core to be solidified while the remaining part of the core is formed of the salt having a lower fusion point than the casting material, wherein the core is manufactured by solidifying the materials after injecting the dispersed materials into a mold in the state that heat resistant rigid powder is uniformly dispersed on the supersaturated water soluble salt, an inorganic material which is not chemically reacted with the salt is used as the heat resistant rigid powder, the heat resistant rigid powder and the fine powder of the water soluble salt having a higher fusion point than the casting material which is dispersed on the supersaturated water soluble salt are dispersed in an amount of 5 to 60 wt.%, based on the total content, the core material of water soluble salt having a lower fusion point is KNO3, KNO2 or NaNO2, and the core material of salt having a higher fusion point is NaCl, KCl, MgCl2, CaCl2 or Na2SO4.