Constitutive equations and computational procedures for modeling nano/micro-scale superplastic forming of bulk metallic glasses

Massachusetts Institute Of Technology, Cambridge MA

Investigators

Abstract

Constitutive equations and computational procedures for modeling nano/micro-scale superplastic forming of bulk metallic glasses Abstract The aim of this research program is to develop material constitutive equations and computational procedures for modeling nano/micro-scale superplastic forming of bulk metallic glasses. We will undertake the following tasks: (a) formulate thermo-mechanically-coupled, large-deformation, elastic-visco-plastic constitutive models for amorphous metals to represent the temperature and strain-rate-dependent mechanical behavior of these materials in the high temperature range, both above and below the glass transition temperature of the material; and (b) develop a finite-element-based simulation and design capability for nano/micro-hot-embossing. This study will (i) help elucidate the relationship between material properties, processing conditions, and part quality during nano/micro-hot-embossing of these materials; and (ii) help shed light on the limits of applicability of classical continuum-mechanical theories of solid and fluid material behavior, which are length-scale independent; and perhaps lead to the development of new theories with material length-scale dependence.