http://nanomechanics.mit.edu/sites/default/files/documents/Kumar_03.pdf

Mechanical behavior of nanocrystalline metals and alloys

Synthesis and mechanical behavior of nanostructured materials via cryomilling

In recent years, much progress has been made in the studies of nanostructured Al alloys for advanced structural and functional use associated both with the development of novel routes for the fabrication of bulk nanostructured materials using severe plastic deformation (SPD) techniques and with investigation of fundamental mechanisms leading to improved properties. This review paper discusses new concepts and principles in application of SPD processing to fabricate bulk nanostructured Al alloys with advanced properties. Special emphasis is placed on the relationship between microstructural features, mechanical, chemical, and physical properties, as well as the innovation potential of the SPD-produced nanostructured Al alloys.

Nanostructured aluminium alloys produced by severe plastic deformation: New horizons in development

Grain size effects on the fatigue response of nanocrystalline metals

In order to develop high strength metal–matrix composites with acceptable ductility, bulk nanostructured aluminum–matrix composites reinforced with graphene nanoflakes were fabricated by cryomilling and hot extrusion processes. Microstructure and mechanical properties were characterized and determined using transmission electron microscopy, electron dispersion spectroscopy, as well as static tensile tests. The results show that, with an addition of only 0.5 wt% graphene nanoflakes, the bulk nanostructured aluminum/graphene composite exhibited increased strength and unsubdued ductility over pure aluminum. Besides, the mechanical properties of the composites with higher content of graphene nanoflakes were also measured and investigated. Above 1.0 wt% of graphene nanoflakes, however, this strengthening effect sharply dropped due to the clustering of graphene nanoflakes. Furthermore, the optimal addition of graphene nanoflakes into the nanocrystalline aluminum matrix was calculated and discussed.

Microstructure and tensile properties of bulk nanostructured aluminum/graphene composites prepared via cryomilling

In the present study, the relationships between the structure and properties of a cryomilled Al-7.5 pct Mg alloy were investigated. The microstructure of the cryomilled Al-7.5 pct Mg alloy consisted of equiaxed grains with an approximate size of 300 nm. Thermal treatment had only a minor effect on microstructure, as evidenced by X-ray diffraction (XRD) and transmission electron microscopy (TEM) results. The tensile behavior was characterized by high strength, high ductility, and low-strain-hardening. The tensile deformation was relatively uniform, with limited necking deformation, and fracture surfaces were characterized by microdimples. The variation of strain rates from 4 · 10−4 to 4 · 10−2 s−1 had an insignificant effect on tensile behavior. Comparison of compressive and tensile behavior revealed similar moduli and yield strengths, although the postyield behavior was markedly asymmetric. The present results indicate that grain-size effects, solid-solution strengthening, Orowan strengthening, and dislocation strengthening contribute significantly to the properties of a cryomilled Al-7.5 pct Mg alloy.

B. O. Han

Papers

Mechanical properties of an ultrafine-grained Al-7.5 Pct Mg alloy

Preparation and study of 3D printed dipyridamole/β-tricalcium phosphate/ polyvinyl alcohol composite scaffolds in bone tissue engineering