TY - JOUR

T1 - High-pressure-torsion-induced segregation, precipitation and grain refinement of Al-(Si, Mg and Cu) binary alloys

AU - Feng, Man

AU - Wu, Qinli

AU - Xue, Jing

AU - Luo, Zhenjiao

AU - Wang, Zhiping

AU - An, Xianghai

AU - Liao, Xiaozhou

AU - LI, Jiehua

AU - Jin, Shenbao

AU - Sha, Gang

N1 - Publisher Copyright: © 2024

PY - 2024/11/10

Y1 - 2024/11/10

N2 - To uncover the effects of segregation and precipitation on grain refinement of metals under severe plastic deformation, high-pressure-torsion (HPT) processing is performed on three binary Al-(Si, Mg, and Cu) alloys with different stability and segregation characteristics. Atom probe tomography analysis reveals that HPT processing induces significant decomposition of Al-1 at% Si and Al-1 at% Cu alloys with coarse Si particles and fine Al 2Cu (θ) precipitates formed, but no decomposition of Al-1 at% Mg alloy, with dislocations segregated with Si, Cu, and Mg, and grain boundaries (GBs) only segregated with Cu and Mg. The GB segregation of Cu is stronger than that of Mg and Si, with Cu excess in the range of 1.5–7.0 atoms/nm 2, Mg excess in the range of 0–4.0 atoms/nm 2, but no Si excess. Interestingly, some GBs without Mg segregation develop a Mg-depletion zone along a single side. All evidences demonstrate that GB segregation and precipitation are responsible for HPT-induced grain refinement of Al-1Mg and Al-1Cu alloys but coarsening of the Al-1Si alloy. Engineering solute distribution is of significance in controlling the ultrafine grain of the Al alloys.

AB - To uncover the effects of segregation and precipitation on grain refinement of metals under severe plastic deformation, high-pressure-torsion (HPT) processing is performed on three binary Al-(Si, Mg, and Cu) alloys with different stability and segregation characteristics. Atom probe tomography analysis reveals that HPT processing induces significant decomposition of Al-1 at% Si and Al-1 at% Cu alloys with coarse Si particles and fine Al 2Cu (θ) precipitates formed, but no decomposition of Al-1 at% Mg alloy, with dislocations segregated with Si, Cu, and Mg, and grain boundaries (GBs) only segregated with Cu and Mg. The GB segregation of Cu is stronger than that of Mg and Si, with Cu excess in the range of 1.5–7.0 atoms/nm 2, Mg excess in the range of 0–4.0 atoms/nm 2, but no Si excess. Interestingly, some GBs without Mg segregation develop a Mg-depletion zone along a single side. All evidences demonstrate that GB segregation and precipitation are responsible for HPT-induced grain refinement of Al-1Mg and Al-1Cu alloys but coarsening of the Al-1Si alloy. Engineering solute distribution is of significance in controlling the ultrafine grain of the Al alloys.

KW - Al alloys

KW - Grain refinement

KW - High pressure torsion

KW - Precipitation

KW - Segregation

UR - http://www.scopus.com/inward/record.url?scp=85191657494&partnerID=8YFLogxK

U2 - 10.1016/j.jmst.2024.02.046

DO - 10.1016/j.jmst.2024.02.046

M3 - Article

VL - 199.2024

SP - 102

EP - 113

JO - JOURNAL OF MATERIALS SCIENCE & TECHNOLOGY

JF - JOURNAL OF MATERIALS SCIENCE & TECHNOLOGY

SN - 1005-0302

IS - 10 November

ER -