Mikrostruktur- und Ausscheidungscharakterisierung von Al-Mg-Mn-Legierungen

Research output: ThesisMaster's Thesis

Authors

Abstract

In this master thesis, the development of microstructure and dispersoids in Al-Mg wrought alloys with varying Fe- and Mn-contents is investigated during processing into cold strip. The samples are melted in a tilting crucible furnace and in a miniature vacuum induction furnace in order to achieve different cooling rates during casting. Homogenization is carried out at two different temperatures and primary phases as well as dispersoids in the treated samples are analyzed using electron microscopy. The latter appear in round shape (identified as Al6Mn) and in needle shape (identified as Fe-containing particles). The rolling process consists of hot rolling, intermediate annealing and cold rolling. It generates sheets with a cold rolling degree of both 18 % and 63 %. The base for the cold rolling degrees is hot rolling of ingots to two different final thickness values. After an intermediate annealing treatment right after hot rolling, the microstructure is still elongated in rolling direction and primary phases are present in line arrangement. Cold rolling results in grain refinement and intensification of the microstructure elongation and the line arrangement of primary phases. Finally, soft annealing is carried out for the purpose of recrystallization. The existing highly deformed grain structure is modified into a new, low-dislocation microstructure with less elongated grains. Electron microscopy analysis shows that with all different parameters during heat treatment and rolling, a large variety of structural details can be achieved.

Details

Translated title of the contributionCharacterization of microstructure and precipitation in Al-Mg-Mn alloys
Original languageGerman
QualificationDipl.-Ing.
Awarding Institution
Supervisors/Advisors
Award date20 Dec 2019
Publication statusPublished - 2019