| 摘要 |
Simplified heat-treatment in making aluminum alloys castings of the type improved by aging, especially for automotive engine cylinder heads and motor blocks. The castings, after solidification and extraction form their molds, each have en end product (workpiece) portion and a riser portion (the latter being ultimately cut off as waste). The workpiece portion of the casting is selectively quenched from solution temperatures down to about 120 ~C by spraying water or other appropriate liquid preferably as a gas driven mist onto the surfaces of the workpiece while maintaining the riser portion of th e casting essentially unsprayed at relatively significantly higher temperature s. After the quench, the residual reservoir of heat thus retained by said riser portion, by internal heat conduction, reheats the workpiece portion and maintains such workpiece portion for an effective time period within the temperature range for artificial aging, thus obviating any need for the agin g furnace used by the prior art. Preferably, the quench is immediately after t he casting mold extraction (without the standard natural cooling, reheating, an d solution heat-treatment, all prior to quenching), thus obviating also the ne ed for a solution heat-treatment furnace, required by the conventional prior ar t.
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