MSE 2022
Lecture
29.09.2022
Thermo-mechanical gradation of high strength aluminum alloy AA7075 by differential cooling strategies
ES

Dr.-Ing. Emad Scharifi

RWTH Aachen University

Scharifi, E. (Speaker)¹; Weidig, U. (Speaker)¹; Steinhoff, K.¹
¹University of Kassel
Vorschau
21 Min. Untertitel (CC)

Inspired by steel forming strategies, this study focuses on the effect of differential cooling on mechanical properties and precipitation kinetics during hot stamping of high strength aluminum alloy AA7075. For this aim, different forming strategies were performed using segmented and differentially heated forming tools to provide locally varying cooling rates. Upon processing, uniaxial tensile tests and hardness measurements were used to characterize the mechanical properties after the aging treatment. Microstructure investigations were conducted to deduce the underlying strengthening mechanisms using transmission electron microscopy (TEM). Based on the obtained results, it can be concluded that the tool temperatures play a key role in influencing the mechanical properties. Lower tool temperatures result in higher material strength and higher tool temperatures in lower mechanical properties. By changing the cooling rate with the use of differently heated forming tools, the mechanical properties can be controlled. Microstructure investigations revealed the formation of very fine and homogeneously distributed particles at cooled zones, which are associated with elevated mechanical properties, due to the suppression of second phase particle formation during cooling. In contrast, coarse particles were observed at lower cooling rates, explaining the lower material strength found in these zones.

Ähnliche Beiträge

© 2025