| 摘要 |
PURPOSE:To manufacture easily a die which can be formed by decreased machining by coating the cavity of a casting mold formed of a ceramic slurry with an air permeable casting mold provided with a sprue and subjecting the die obtd. by pouring a molten metal into the mold to electric discharge machining. CONSTITUTION:Three layers consisting of zircon flower, mold coating material and xylol resin are successively formed on the surface of a die pattern 3 consisting of rigid foamed urethane formed by allowing for a margin for elongation, margin for working, etc. The pattern 3 is set in a flask 5 and a ceramic slurry 6 is cast therein from above and is soldified. The slurry is allowed to dry naturally and is calcined to form a ceramic casting mold 9. The mold 9 is set between a cope 10 and a draft 11 and a molten metal M is poured into the cavity 9a of the mold 9 through the sprue 13 of the cope 10 to form a casting 16. The casting 16 is subjected to machining, hardening and tempering then to electric discharge machining by a discharge electrode followed by prescribedfinish working, by which an intended die 18 is obtd. |
