Effect of Processing Temperature on Microstructure Development during ECAP of Al-Mg-Sc Alloy

Abstract:

Article Preview

Microstructural evolution taking place during equal channel angular pressing (ECAP) was studied in a commercial coarse-grained Al-6%Mg-0.4%Mn-0.3%Sc alloy in a temperature interval 200- 450oC (~0.5-0.8 Tm). Samples were pressed using route A to a total strain of 12 and quenched in water after each ECAP pass. Uniform fine-grained microstructures with the average grain sizes of 0.7 and 2.5 0m, are almost fully evolved at high ECAP strains at 250oC and 450oC, respectively, while ECAP at 300oC (~0.6 Tm) leads to the formation of bimodal grain structure with fine grains of around 1 µm and relatively coarse grains of around 8 µm. The latter are developed due to the occurrence of static recrystallization during “keeping” time in the ECAP channel and/or reheating between ECAP passes. The microstructural development under warm-to-hot ECAP conditions is discussed in terms of the large potential for grain boundary migration resulted from an overlapping of accelerated grain boundary mobility at high pressing temperatures and enhanced driving force for recrystallization, which is caused by a strong inhibition of dynamic recovery in a heavily-alloyed Al alloy.

Info:

Periodical:

Materials Science Forum (Volumes 584-586)

Edited by:

Yuri Estrin and Hans Jürgen Maier

Pages:

481-486

DOI:

10.4028/www.scientific.net/MSF.584-586.481

Citation:

O. Sitdikov et al., "Effect of Processing Temperature on Microstructure Development during ECAP of Al-Mg-Sc Alloy", Materials Science Forum, Vols. 584-586, pp. 481-486, 2008

Online since:

June 2008

Export:

Price:

$35.00

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