Strong resistance to shear instability in multilayered metallic composites by nanoscale amorphous-BCC crystalline interfaces

Quantifying the Size-Dependent Shear Banding Behavior in High-Entropy Alloy-Based Nanolayered Glass

“…When h further decreases to 10 nm, three kinking-like primary SBs appeared, accompanied by multiple secondary SBs. A large number of nano/microindentation experiments have validated that the reduction in the number of SBs corresponds to the reduction in the shear instability of the sample under a complex stress state [ 21 , 43 , 55 , 61 , 62 ]. In addition, the shear instability of the cutting-like SBs is generally greater than that of the kinking-like SBs [ 21 , 61 ].…”

“…A large number of nano/microindentation experiments have validated that the reduction in the number of SBs corresponds to the reduction in the shear instability of the sample under a complex stress state [ 21 , 43 , 55 , 61 , 62 ]. In addition, the shear instability of the cutting-like SBs is generally greater than that of the kinking-like SBs [ 21 , 61 ]. Thus, the shear instability resistance of the Cu x (TiZrNb) 100− x NLGs gradually increases with the decrease of layer thickness.…”

“…In order to accurately quantify the degrees of shear instability within the SBs of the samples with different layer thicknesses, a theoretical model including two SB modes, i.e., the kinking-like and cutting-like SBs, was proposed based on the previous work of our group [ 21 ] ( Figure 9 ). It was assumed that the SB region is subject to a pure shear stress state.…”

“…Therefore, improving the plasticity and tensile ductility of MGs while simultaneously maintaining their ultra-high strength has become an important issue in the field of materials science in recent decades [ 11 , 12 , 13 , 14 ]. Significant efforts have been made to achieve the above goal, and several typical and effective strategies based on interface engineering have emerged, which have generated the high density of crystalline/amorphous (C/A) and amorphous/amorphous (A/A) interfacial structures at the nanoscale [ 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 ].…”

“…However, most of the existing studies have focused on the shear banding-induced surface morphologies during the indentation process. What happened inside the materials underneath the indenter remains unclear, especially the specific characteristics of the SBs, including the shear banding mode (cutting-like or kinking-like SBs) [ 21 ]. Another important issue is that a theoretical model that can be used to quantify the shear banding-induced strain localization in the amorphous alloys is still lacking.…”