Microstructural evolution in a spray-cast aluminum alloy during equal-channel angular pressing

[摘要] A spray-cast Al-7034 alloy was processed by equal-channel angular pressing (ECAP) to a total of eight passes at 473 K and the pressed samples were examined using transmission electron microscopy, differential scanning calorimetry and electron back-scatter diffraction. It is shown that the grain size of the alloy is reduced to -0.3 mu m by ECAP and the high pressures associated with ECAP lead to a fragmentation of the rod-like eta-phase. The high temperature of ECAP also produces a precipitation of eta-phase. There is an increase in the fraction of high-angle boundaries during the initial passes of ECAP but the fraction of low-angle boundaries remains high even after eight passes. (c) 2005 Elsevier B.V. All rights reserved.

[发布日期] 2005-11-25

[效力级别]  Proceedings Paper

[关键词] equal-channel angular pressing;grain boundary misorientation;precipitation;thermal processes;ultrafine grains