Apparatus for simplified production of heat treatable aluminum alloy castings with artificial self-aging

Abstract

Apparatus for simplified heat-treatment in making aluminum alloys castings of the type improved by aging, especially for automotive engine heads, etc. The newly solidified castings have an end product (workpiece) portion and a riser portion (ultimately cut off as waste). The apparatus transfers the casting oriented to selectively quench the workpiece portion from solution temperatures down to about 120° C. (e.g. by water misting the workpiece, while maintaining the essentially unsprayed riser portion at relatively significantly higher temperatures). After the quench, the residual heat retained by the riser portion reheats the workpiece portion (by internal heat conduction) and maintains it for an effective time within the temperature range for artificial aging (obviating any need for the prior art's aging furnace). Preferably, the quench occurs immediately after the casting mold extraction (without the standard natural cooling, reheating, and solution heat-treatment, all prior to quenching), thus also eliminating any solution heat-treatment furnace.

Description

[0001] This is a division of application Ser. No. 09 / 458,347, filed Dec. 10, 1999.[0002] The present invention relates to a method and apparatus for making aluminum alloys castings, wherein the heat-treatment processes of the prior art are simplified, by actually eliminating some traditional steps and equipment. The invention is applicable for example in the production of cylinder heads, motor blocks and the like, for automotive engines. The invention provides many advantages over the prior art heat-treatments, with an increased productivity of the casting plants, and lower capital and operation costs as well. The invention is particularly useful for producing aluminum alloys of the 3xx.x series of the classification of the Aluminum Association (AA), especially for T6 and T7 properties.[0003] This invention is broadly applicable to the production of any aluminum alloy casting which in the past has derived meaningful benefit from quenching and artificial aging in an aging furnace. Th...

AI Technical Summary

Benefits of technology

0015] The present invention improves upon the applicants' aforementioned U.S. Pat. No. 5,922,147 patent by simplifying even further the overall heat-treatment of the castings, although broadly it can be applied separately. The invention dispenses with the aging furnace, in addition to pre

Problems solved by technology

During the cooling process, particularly if the cooling is carried out at a slow rate, there is a tendency for the different elements to become segregated.

Furthermore, Koppenhoefer does not teach or suggest applicants' invention of selectively quenching only the end product portion of the casting in order to use eventually

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