On The Mechanism Of Deformation Localization And Homogeneous Flow In Bulk Metallic Glasses
Free (open access)
235 - 244
J. C. Li, X. W. Chen, F. L. Huang
A modified coupled thermo-mechanical constitutive model for bulk metallic glasses (BMGs) is deduced in the present manuscript. Besides, a failure criterion of critical free volume concentration is introduced. The constitutive model as well as the failure criterion is implemented into the LS-DYNA commercial software through the user material subroutine (UMAT). Finite element method (FEM) simulations for different initial material temperatures and strain rates are conducted, and the evolutions of material parameter as well as the corresponding macroscopic mechanical behavior of material are analyzed. Related analysis shows that at room temperature, the deformation and failure characteristics in the shear band zones of BMGs are significantly different from that in the matrix, and consequently high deformation localization occurs. Comparatively, within the supercooled liquid region, the mechanical behaviors in the shear band zones and that in the matrix are similar to each other, and thus BMGs usually behave as homogeneous flow.
bulk metallic glass, deformation, constitutive model, FEM simulation