title: Segregation of solute elements at grain boundaries in an ultrafine grained Al-Zn-Mg-Cu alloy.
abstract: The solute segregation at grain boundaries (GBs) of an ultrafine grained (UFG) Al-Zn-Mg-Cu alloy processed by equal-channel angular pressing (ECAP) at 200 °C was characterised using three-dimensional atom probe. Mg and Cu segregate strongly to the grain boundaries. In contrast, Zn does not always show clear segregation and may even show depletion near the grain boundaries. Trace element Si selectively segregates at some GBs. An increase in the number of ECAP passes leads to a decrease in the grain size but an increase in solute segregation at the boundaries. The significant segregation of alloying elements at the boundaries of ultrafine-grained alloys implies that less solutes will be available in the matrix for precipitation with a decrease in the average grain size.
authors.affiliation: Australian Centre for Microscopy & Microanalysis, The University of Sydney, NSW 2006, Australia. g.sha@usyd.edu.au, gang.sha@sydney.edu.au
authors.forename: Gang
authors.initials: G
authors.lastname: Sha
authors.forename: Lan
authors.initials: L
authors.lastname: Yao
authors.forename: Xiaozhou
authors.initials: X
authors.lastname: Liao
authors.forename: Simon P
authors.initials: SP
authors.lastname: Ringer
authors.forename: Zhi
authors.initials: Z
authors.lastname: Chao Duan
authors.forename: Terence G
authors.initials: TG
authors.lastname: Langdon