Paper Title:
Geometric Dynamic Recrystallization in an AA2219 Alloy Deformed to Large Strains at an Elevated Temperature
  Abstract

The mechanism of new grain evolution during equal channel angular extrusion (ECAE) up to a total strain of ~12 in an Al-Cu-Mn-Zr alloy at a temperature of 475oC (0.75Tm) was examined. It was shown that the new grains with an average size of about 15 µm result from a specific process of geometric dynamic recrystallization (GRX) which can be considered as a type of continuous dynamic recrystallization (CDRX). This process involves three elementary mechanisms. At moderate strains, extensive elongation of initial grains takes place; old grain boundaries become progressively serrated. Upon further ECAE processing, transverse low-angle boundaries (LAB) with misorientation ranging from 5 to 15o are evolved between grain boundary irregularities subdividing the initial elongated grains on crystallites with essentially equiaxed shape. The misorientation of these transverse subboundaries rapidly increases with increasing strain, resulting in the formation of true recrystallized grains outlined by high-angle boundaries from all sides. In the same time, the average misorientation of deformation-induced boundaries remains essentially unchanged during ECAE. It is caused by the fact that the evolution of LABs with misorientation less than 4o occurs continuously during severe plastic deformation. The mechanism maintaining the stability of the transverse subboundaries that is a prerequisite condition for their further transformation into highangle boundaries (HABs) is discussed.

  Info
Periodical
Materials Science Forum (Volumes 467-470)
Edited by
B. Bacroix, J.H. Driver, R. Le Gall, Cl. Maurice, R. Penelle, H. Réglé and L. Tabourot
Pages
1199-1204
DOI
10.4028/www.scientific.net/MSF.467-470.1199
Citation
R. Kaibyshev, I. Mazurina, O. Sitdikov, "Geometric Dynamic Recrystallization in an AA2219 Alloy Deformed to Large Strains at an Elevated Temperature", Materials Science Forum, Vols. 467-470, pp. 1199-1204, 2004
Online since
October 2004
Export
Price
$32.00
Share

In order to see related information, you need to Login.

In order to see related information, you need to Login.

Authors: Rustam Kaibyshev, I. Mazurina
Abstract:The mechanisms of grain refinement during severe plastic deformation have been studied, by comparing the microstructure evolution in an...
1251
Authors: I. Mazurina, Alexandre Goloborodko, Rustam Kaibyshev, Hiromi Miura, Taku Sakai
Abstract:Microstructural evolution during equal channel angular extrusion (ECAE) was investigated in a coarse-grained dilute aluminum alloy, Al-3%Cu,...
829
Authors: Marat Gazizov, Rustam Kaibyshev
Chapter 2: Aluminium Alloys
Abstract:A novel Al-Cu-Mg-Ag alloy with small additions of zirconium and scandium was subjected to equal channel angular pressing (ECAP) by using...
41
Authors: Rustam Kaibyshev, Sergey Malopheyev
Chapter 9: Novel Processes and Materials
Abstract:Mechanisms of dynamic recrystallization operating at severe plastic deformation in a wide temperature range are reviewed for aluminum alloys....
784
Authors: Rustam Kaibyshev, Sergey Malopheyev, Vladislav Kulitskiy, Marat Gazizov
Chapter 21: Ultra-Fine – Grained Materials (Prof. T.G. Langdon Symposium)
Abstract:The mechanism of grain refinement in an Al-5.4Mg-0.4Mn-0.2Sc-0.09Zr alloy subjected to equal-channel angular pressing (ECAP) at 300°C through...
2641