Impact of crystalline-amorphous interface on shock response of metallic glass Al90Sm10/crystalline Al nanolaminates

S Mishra and KV Reddy and S Pal, APPLIED PHYSICS A-MATERIALS SCIENCE & PROCESSING, 127, 774 (2021).

DOI: 10.1007/s00339-021-04929-4

In this paper, structural evolution of single-crystal Al (SC)-metallic glass (MG) Al90Sm10 nanolaminate specimens under shock compression has been investigated using molecular dynamics simulations. Shock profile analysis of the SC-MG nanolaminate specimen reveals the presence of elastic precursor at lower piston velocity in the crystalline region of the nanolaminates eventuating due to plane-plane collision. Shock- induced martensitic phase transformation is apparent in the nanolaminate specimen at higher shock intensities. Rarefaction waves are observed to be generated at the crystalline-amorphous interface, which aid in stabilization of the transformed martensitic phase. The role of interface reverses with altering the direction of shockwave to induce from the metallic glass end of the nanolaminate. The attenuation of shockwave in the amorphous MG region and the absence of rarefaction waves at the interface impede the martensitic phase transformation. Icosahedral-like cluster < 0, 2, 8, 4 > is found to be most resistant to shockwave deformation as analyzed using Voronoi cluster analysis. Formation of shear transformation zones (STZs) plays a vital role in absorbing the shock in the metallic glass region of nanolaminate specimen.

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