Patent ID: 7987895

Claim:
A method for forming an aluminum alloy casting in a sand mold, comprising: providing a sand mold defining a cavity for forming said casting with at least one first portion of said mold formed with a binder soluble in a given solvent and at least one second portion formed with binder insoluble in said solvent, such at least one first portion being positioned to define respective areas of the casting cavity for achieving respective localized rapid cooling of the casting; filling said mold with liquid aluminum alloy; directing at least one cooling stream of solvent onto such at least one first portion to wash out such respective first portion to expose and directly cool the solidifying casting to give accelerated cooling of at least one respective defined area, with such at least one second insoluble portion serving to delimit such respective defined area and to protect the solidifying casting at the remaining locations of the casting cavity from such relatively accelerated cooling.