On nanovoids formation in shear bands of an amorphous Al-based alloy

Shear bands play a key role in the deformation of amorphous alloys at room, low and elevated (below the glass transition) temperatures. The shear bands in the amorphous Al-Ni-Y are places of nanocrystal formation during the rolling deformation. As Al nanocrystal formation occurs by the diffusion mechanism; their composition is different from the composition of the amorphous matrix. The nanovoids formed by the coalescence of excess free volume during prolonged aging at room temperature were observed in the shear bands by transmission electron microscopy method. The obtained apparent diffusion coefficient in the shear band at room temperature of 10−22 m2s−1 exceeds by 5-6 orders in magnitude the diffusion coefficient in the matrix.