Yield surface of a simulated metallic glass

We perform molecular simulations of multiaxial deformation in a model metallic glass using a zero-Kelvin energy minimization technique. We find that there is a pronounced asymmetry between the magnitudes of the yield stresses in tension and compression, with the uniaxial compressive strength approximately 24% higher. By exploring a variety of biaxial stress states, we probe the plane-stress yield surface and find that it is not well-described by traditional yield criteria that depend only on the maximum shear stress. In contrast, the Mohr-Coulomb criterion, which includes an additional normal stress term, is found to describe the data quite well. Finally, the simulation results are shown to compare favorably with the available experimental data. (C) 2003 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.