A. Rose, O. Keßler, F. Hoffmann, H.-W. Zoch, P. Krug
April 27, 2013
In quenching of age hardenable aluminum alloys, today predominantly aqueous quenching media are used, which can lead to a non-uniform cooling of the components due to the Leidenfrost phenomenon, and thus to distortion. In relation to the conventional quenching procedures in aqueous media, gas quenching has a number of technological, ecological, and economical advantages. The quenching intensity can be adjusted by the variable parameters gas pressure, gas velocity as well as the kind of gas and thus can be adapted to the requirements of the component. By the higher uniformity and the better reproducibility, gas quenching offers a high potential for reducing distortion. It could be demonstrated that characteristic shape and dimension changes of forged components of the spray formed aluminum alloy DISPAL S232 (Al-17Si-4Fe-3Cu-0.5Mg-0.4Zr) are clearly lower after gas quenching than after water quenching. Thereby suitable processes proved to be high-pressure gas quenching with nitrogen at 10 bar as well as air quenching in a gas nozzle field. Cost saving would be possible, because of reduced distortion and therefore less reworking.