Abstract
The local atomic structure of metallic glasses can be modified, and their physical properties can be improved by high-pressure torsion (HPT). In this article, some recent investigations are presented that reveal the HPT treatment effect on nanoglass (Zr55.7Ni10Al7Cu19Co8.3) based upon the appearance of shear bands in the HPT treated nanoglass. The residual stress rises, leading to an increase in the nanoindentation hardness. With the evolution of the free volume, the plasticity of the nanoglass is improved by HPT, exhibiting a tensile plastic strain of 0.9%. Multiple shear bands can be observed on the surface during the tensile test, and crack propagation is suppressed in HPT-treated nanoglass. Many shear bands branch and interact with each other at the tip of the cracks thus avoiding brittle behavior.
Keywords
Nanoglass, HPT, Tensile plasticity, Free volume, Shear bands.