Auswirkung der Tieftemperaturumformung auf die Aushärtungskinetik von AlMgSi- Legierungen

Research output: ThesisMaster's Thesis

Abstract

Increased efforts to reduce CO2 emissions and innovations in the e-mobility sector raised the use of lightweight constructions in the automotive industry. Especially hardenable aluminum alloys show a high potential due to their excellent density to strength ratio. This thesis deals with the effect of low temperature forming on artificial aging kinetics of two types of hardenable alloys, EN AW 6016 and EN AW 6063. The goal of the experiments is to determine the strength under different degrees of pre-deformation of 5 %, 10 % and 20 %, followed by a heat treatment. The deformation is carried out in a special cryochamber filled with liquid nitrogen as well as under room temperature. Additionally, the material is heat treated for various time periods at 185 °C. The main task is to determine the aging kinetics through hardness. Furthermore, tensile tests until fracture of selected pre-treated samples are carried out, to evaluates the formability, yield strength and strain hardening capability. The stress strain curves and the hardness curves show regular trends at room temperature in relation to the literature. Basically, the under liquid nitrogen tested samples show higher strength and strain parameters. The reason is located in the increasing dislocation density regarding to the cryogenic deformation. By low-temperature forming, the proportion of work hardening and simultaneously the lattice defects increase due to low recovery. Also the heat treatments of the samples are important because sample in pre-aged condition exhibit higher strength and slightly different aging behavior.

Details

Translated title of the contributionEffect of low temperature deformation on the age-hardening kinetics of AlMgSi alloys
Original languageGerman
QualificationDipl.-Ing.
Awarding Institution
Supervisors/Advisors
Award date28 Jun 2019
Publication statusPublished - 2019