High Temperature Ductility and Deformation Mechanism in a 2024 Aluminium Alloy

摘要

Temperature dependence of ductility has been investigated in a range from 733K to 793K at strain rates from 1.4 x 10~(-4) s~(-1) to 2.8 x 10~(-1)s~(-1) in a 2024 aluminum alloy. A peak of elongation about 743K is observed at higher strain rates while the peak about 783K is at lower strain rates. Microstructures after deformation in both conditions are compared using SEM/EBSP (electron backscatter diffraction pattern) analysis. As a result, a large amount of intragranular misorientation is found in the specimen deformed at the high strain rate. On the other hand, a high fraction of random boundaries is present in the specimen deformed at the low strain rate. Further, relation between high temperature ductility and deformation mechanism is discussed.