Smirnov A.S.,Russian Academy of Sciences |
Konovalov A.V.,Russian Academy of Sciences |
Pushin V.G.,RAS Institute of Metal Physics |
Uksusnikov A.N.,RAS Institute of Metal Physics |
And 2 more authors.
Journal of Materials Engineering and Performance | Year: 2014
The paper deals with a peculiar rheological behavior of the Al-Mg-Sc-Zr alloy at deformation temperatures of 330 and 360 °C and a strain rate of 0.05 s−1. It has been found that the strain resistance curve for this material consists of several portions. First there is material hardening, then softening, and again hardening. The application of the electron backscatter diffraction technique and transmission electron microscopy has elucidated that in-situ recrystallization is the main process of softening at the temperatures studied. The appearance of the second portion of hardening on the strain resistance curve results from inhibited in-situ recrystallization. At the deformation temperature of 330 °C, as distinct from the temperature of 360 °C, a small number of grains are formed on the boundaries of original grains because of insufficiently active dynamic polygonization. The presence of abounding intermetallics in the microstructure causes the development of the barrier effect of blocking free dislocations, grain and subgrain boundaries by intermetallics, thus enhancing material hardening. © 2014, ASM International.