This paper studies the high temperature mechanical properties of as-cast Al–Zn–Mg using tensile and creep testing. Hot tensile tests were performed in the temperature and strain rate ranges of 350–400 ◦C and 10−5 to 10−3 s−1 respectively. Creep tests were carried out under constant load with initial stress ranging from 5 to 22 MPa, at 350 and 400 ◦C. The alloy exhibits class A creep behavior, due to the viscous glide of dislocations. The tensile flow curves, corrected to account for the effect of sample elongation on strain rate, also show a decline in stress commonly observed in Al–Mg alloys. The highest ductility and strain rate sensitivity were both observed for strain rates ranging from 10−5 to 10−4 s−1. During hot deformation the alloy exhibits cavitation which increases with temperature. The analysis of these phenomena has shown that cavity growth is mainly controlled by plastic strain.
High temperature mechanical properties of an aluminium alloy containing Zn and Mg
LEO, PAOLA;
2012-01-01
Abstract
This paper studies the high temperature mechanical properties of as-cast Al–Zn–Mg using tensile and creep testing. Hot tensile tests were performed in the temperature and strain rate ranges of 350–400 ◦C and 10−5 to 10−3 s−1 respectively. Creep tests were carried out under constant load with initial stress ranging from 5 to 22 MPa, at 350 and 400 ◦C. The alloy exhibits class A creep behavior, due to the viscous glide of dislocations. The tensile flow curves, corrected to account for the effect of sample elongation on strain rate, also show a decline in stress commonly observed in Al–Mg alloys. The highest ductility and strain rate sensitivity were both observed for strain rates ranging from 10−5 to 10−4 s−1. During hot deformation the alloy exhibits cavitation which increases with temperature. The analysis of these phenomena has shown that cavity growth is mainly controlled by plastic strain.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
