Tensile behavior of bulk nanocrystalline aluminum synthesized by hot extrusion of ball-milled powders

• DOI: 10.1016/j.scriptamat.2008.07.030
• Publication Date: 2008-07-31T13:38:13Z
• Authors: H.J. Choi; S.W. Lee; J.S. Park; D.H. Bae
• Keywords: Nanocrystalline material; Grain boundary strengthening

The deformation behavior of bulk nanocrystalline aluminum down to 48 nm in grain size, produced by hot extrusion of ball-milled powders, has been evaluated by compression and tension tests. Isotropic yield stress increases following the Hall–Petch relationship with decreasing grain size down to 70 nm. However, a positive deviation in the relationship is found for grain sizes below 70 nm, and aluminum with a grain size of 48 nm exhibits a superior yield stress of 500 MPa with ductile failure.