Constitutive Modeling in Metallic Glasses for Predictions and Designs

Abstract

Metallic glasses, made of metallic elements yet possessing an amorphous structure, have attracted considerable interest due to their unique mechanical properties and excellent net-shape forming ability. In terms of mechanical properties, they are extraordinary in elastic limit and strength but inferior in ductility at room temperature, where the inhomogeneous deformation characteristics of shear banding, flow serration, and sometimes cavitation prevail. The netshape forming ability surfaces when the temperature rises above Tg (i.e., the glass transition temperature), where metallic glasses deform in a homogeneous manner. Understanding both the homogeneous and inhomogeneous deformation in metallic glasses is pivotal for promoting their potential applications. In this course, the continuum mechanics constitutive modeling has played a critical role. The constitutive modeling can be used for either predicting the mechanical responses of metallic glasses under various loading conditions or guiding material, product, and process designs. In this chapter, a number of important constitutive models for metallic glasses are reviewed; their applications in predicting both the homogeneous and inhomogeneous plastic flows are presented; and finally, the attempts of using the constitutive modeling to assist the design of ductility and net-shape forming processes are discussed.