Deformation-induced nanocrystallization: A comparison of two amorphous Al-based alloys

W.H. Jiang, F.E. Pinkerton, M. Atzmon
2005 Journal of Materials Research  
Using conventional and high-resolution transmission electron microscopy (HRTEM), the effects of rolling at room temperature on the microstructures of amorphous Al 90 Fe 5 Gd 5 and Al 86.8 Ni 3.7 Y 9.5 were compared. In rolled Al 90 Fe 5 Gd 5 , nanocrystallites were observed at shear bands, whereas none were observed in rolled Al 86.8 Ni 3.7 Y 9.5 . When HRTEM was combined with with Fourier transform filtering, nanoscale, low-density defects were imaged. In Al 90 Fe 5 Gd 5 , the shear bands
more » ... he shear bands contain few defects, which are concentrated at the boundary zone between the shear bands and undeformed region, whereas in Al 86.8 Ni 3.7 Y 9.5 , the shear bands contain a uniform distribution of defects with a density higher than the undeformed region. The preferential precipitation of nanocrystallites in rolled Al 90 Fe 5 Gd 5 is attributed to a kinetic effect due to uniformly-distributed excess free volume in the shear bands.
doi:10.1557/jmr.2005.0090 fatcat:eg2snwmrfbh6fam35emf3lgqni