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High-velocity projectile impact induced 9R phase in ultrafine-grained aluminium.

ABSTRACT: Aluminium typically deforms via full dislocations due to its high stacking fault energy. Twinning in aluminium, although difficult, may occur at low temperature and high strain rate. However, the 9R phase rarely occurs in aluminium simply because of its giant stacking fault energy. Here, by using a laser-induced projectile impact testing technique, we discover a deformation-induced 9R phase with tens of nm in width in ultrafine-grained aluminium with an average grain size of 140?nm, as confirmed by extensive post-impact microscopy analyses. The stability of the 9R phase is related to the existence of sessile Frank loops. Molecular dynamics simulations reveal the formation mechanisms of the 9R phase in aluminium. This study sheds lights on a deformation mechanism in metals with high stacking fault energies.

SUBMITTER: Xue S

PROVIDER: S-EPMC5698461 | biostudies-literature | 2017 Nov

REPOSITORIES: biostudies-literature

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High-velocity projectile impact induced 9R phase in ultrafine-grained aluminium.

Xue Sichuang S Fan Zhe Z Lawal Olawale B OB Thevamaran Ramathasan R Li Qiang Q Liu Yue Y Yu K Y KY Wang Jian J Thomas Edwin L EL Wang Haiyan H Zhang Xinghang X

Nature communications 20171121 1

Aluminium typically deforms via full dislocations due to its high stacking fault energy. Twinning in aluminium, although difficult, may occur at low temperature and high strain rate. However, the 9R phase rarely occurs in aluminium simply because of its giant stacking fault energy. Here, by using a laser-induced projectile impact testing technique, we discover a deformation-induced 9R phase with tens of nm in width in ultrafine-grained aluminium with an average grain size of 140 nm, as confirmed ...[more]

PMID: 29162804

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