Permanent mould casting of iron-carbon alloys - using plungers to consolidate metal in thick sections solidifying last

摘要

After pouring the metal into the mould, and during solidification, a plunger is pressed into a zone of late solidification so that the liq. metal is pressed against metal which has already solidified. The plunger or ram is pref. incorporated in the mould and it can also be used in a region where a hole is required in the casting. The advantage is the elimination of pipe and porosity in the zone(s) which is/are last to solidify while simultaneously reducing the amt. of machining at these locations; furthermore, the size of the riser above the zone can be reduced thus lowering costs.