Effect of crystalline phase on deformation behaviors of amorphous matrix in a metallic glass composite.

In metallic glass composites (MGCs), the existence of crystalline phases causes the structures of amorphous matrix to become relatively heterogeneous near the crystalline phase, resulting in the difference of mechanical properties in micro- or nano-scale in amorphous matrix near crystalline/matrix interface. In this study, this difference was characterized by nanoindentation technology, and the pile-up height was quantitatively related to the activation volume of shear transformation zones (STZs). Molecular dynamics simulations were conducted to investigate the activation behaviors of STZs during nanoindentation process of amorphous matrix. The influences of crystalline phase on deformation behaviors of amorphous matrix near the interface in MGCs were analyzed in details. • For the interface area of MGCs, the hardnesses of interface, crystalline phase and amorphous matrix increase in turn. • The existence of crystalline phase will cause the gradient distribution of free volume away from the interface in amorphous matrix. • The relationship between the pile-up height of nanoindentation in amorphous matrix, the free volume content and the number of STZs is established. [ABSTRACT FROM AUTHOR]