Verzugsreduzierung beim Wärmebehandeln von Bauteilen aus sprühkompaktierten und gießtechnisch hergestellten Aluminiumlegierungen durch Gasabschrecken

Abstract

For quenching of age hardenable aluminum alloys today predominantly aqueous quenching media are used, which can lead due to the Leidenfrost phenomenon to a non-uniform cooling of the parts and thus to distortion. Particularly at thin-walled or complex shaped parts local plastic deformations can occur by the uneven thermal stresses. In relation to the conventional quenching procedures in aqueous media, gas quenching exhibits a number of technological, ecological and economical advantages. The quenching intensity can be adjusted by the variable parameters gas pressure and gas velocity as well as the kind of gas and thus can be adapted to the requirements of the alloy. By the higher uniformity and the better reproducibility, gas quenching offers a high potential to reduce distortion. For this purpose a new age hardening process was developed, which includes a gas quenching step. The distortion behavior of cast and forged aluminum parts was examined after gas quenching and after water quenching.