Peculiarities of the rheological behavior and structure formation of aluminum under deformation at near-solidus temperatures  

作　　者：A. S. Smirnov A. V. Konovalov G. A. Belozerov V. P. Shveikin E. O. Smirnova 

机构地区：[1]Institute of Engineering Science, Russian Academy of Science (Ural Branch), 34 Komsomolskaya Street, Ekaterinburg 620049, Russia [2]Ural Federal University, 19 Mira Street, Ekaterinburg 620002, Russia

出　　处：《International Journal of Minerals,Metallurgy and Materials》2016年第5期563-571,共9页矿物冶金与材料学报（英文版）

基　　金：financially supported by Russian Science Foundation(No. 14-19-01358)

摘　　要：This paper deals with a peculiar rheological behavior of aluminum at near-solidus temperatures. It has been experimentally estab- lished that there is an inverse strain rate dependence of strain resistance at temperatures ranging between 560 and 640℃ and strain rates ranging from 0.06 to 1.2 s-1. Electron backscatter diffraction analysis has shown that at temperatures ranging between 540 and 640℃ and strain rates ranging from 0.06 to 0.1 s-1, the main process of softening is dynamic polygonization, resulting in in situ recrystallization. At higher strain rates, ranging between 0.8 and 1.2 s-1, and temperatures ranging between 560 and 640℃, the recovery is dynamic. This unusual behavior of the mechanism of softening and the presence of the inverse strain rate dependence of strain resistance can be explained by blocking the motion of free dislocations by foreign atoms, which occurs at strain rates ranging between 0.06 and 0.1 s-1 This process results in dislocation pile-up, thereby causing in sire recrystallization. At strain rates exceeding 0.16 s-1, there is no intensive blocking of dislocations, leading to a direct strain rate dependence of strain resistance.This paper deals with a peculiar rheological behavior of aluminum at near-solidus temperatures. It has been experimentally estab- lished that there is an inverse strain rate dependence of strain resistance at temperatures ranging between 560 and 640℃ and strain rates ranging from 0.06 to 1.2 s-1. Electron backscatter diffraction analysis has shown that at temperatures ranging between 540 and 640℃ and strain rates ranging from 0.06 to 0.1 s-1, the main process of softening is dynamic polygonization, resulting in in situ recrystallization. At higher strain rates, ranging between 0.8 and 1.2 s-1, and temperatures ranging between 560 and 640℃, the recovery is dynamic. This unusual behavior of the mechanism of softening and the presence of the inverse strain rate dependence of strain resistance can be explained by blocking the motion of free dislocations by foreign atoms, which occurs at strain rates ranging between 0.06 and 0.1 s-1 This process results in dislocation pile-up, thereby causing in sire recrystallization. At strain rates exceeding 0.16 s-1, there is no intensive blocking of dislocations, leading to a direct strain rate dependence of strain resistance.

关 键 词：ALUMINUM rheological behavior formation near-solidus temperature 

分 类 号：TG146.21[一般工业技术—材料科学与工程]