A method and apparatus for casting more complicated, thin-walled engraved objects

摘要

A method and die for forming intricate, thin-sectioned castings. A die is provided having a porous metal body, an impervious surface and a mold cavity through the surface and in the porous body. The impervious surface is heated to a melt-metal-shedding temperature at which the casting metal does not adhere to the surface upon its removal from the melt. Air is introduced behind the mold cavity and exits through the cavity's porous walls thereby transpirationally cooling the cavity without substantially cooling the surface. The die is immersed in the casting metal where it is quickly solidified in the cool mold cavity. The process is particularly useful for casting low alloy lead battery grids.