title: Nanostructural hierarchy increases the strength of aluminium alloys.
abstract: Increasing the strength of metallic alloys while maintaining formability is an interesting challenge for enabling new generations of lightweight structures and technologies. In this paper, we engineer aluminium alloys to contain a hierarchy of nanostructures and possess mechanical properties that expand known performance boundaries-an aerospace-grade 7075 alloy exhibits a yield strength and uniform elongation approaching 1 GPa and 5%, respectively. The nanostructural architecture was observed using novel high-resolution microscopy techniques and comprises a solid solution, free of precipitation, featuring (i) a high density of dislocations, (ii) subnanometre intragranular solute clusters, (iii) two geometries of nanometre-scale intergranular solute structures and (iv) grain sizes tens of nanometres in diameter. Our results demonstrate that this novel architecture offers a design pathway towards a new generation of super-strong materials with new regimes of property-performance space.
authors.affiliation: Australian Centre for Microscopy and Microanalysis and ARC Centre of Excellence for Design in Light Metals, The University of Sydney, Sydney, New South Wales 2006, Australia.
authors.forename: Peter V
authors.initials: PV
authors.lastname: Liddicoat
authors.forename: Xiao-Zhou
authors.initials: XZ
authors.lastname: Liao
authors.forename: Yonghao
authors.initials: Y
authors.lastname: Zhao
authors.forename: Yuntian
authors.initials: Y
authors.lastname: Zhu
authors.forename: Maxim Y
authors.initials: MY
authors.lastname: Murashkin
authors.forename: Enrique J
authors.initials: EJ
authors.lastname: Lavernia
authors.forename: Ruslan Z
authors.initials: RZ
authors.lastname: Valiev
authors.forename: Simon P
authors.initials: SP
authors.lastname: Ringer
mesh_terms: D000497:Alloys / Q000737:chemistry*; D000535:Aluminum / Q000737:chemistry*; D008422:Materials Testing; D008853:Microscopy; D049329:Nanostructures / Q000737:chemistry* / Q000648:ultrastructure; D013718:Tensile Strength
chemical_list: D000497:Alloys; D000535:Aluminum