Experimental and numerical investigation of plasticity in metallic glasses via reverse analysis

International audienceMetallic glasses (MG) are amorphous metallic alloys whose elastic and density properties are in the same range as their crystalline counterparts. Strikingly, they exhibit very high yield strains, and extraordinary yield strengths up to several GPa making them promising structural materials. MG are also highly isotropic, homogeneous and size effect free materials. They represent an alternative to fused silica as reference material in Instrumented Indentation Technique (IIT). However, MG are macroscopically brittle and the mechanisms involved in their plasticity are still debated. In this study, we aim to identify plasticity of MG via IIT using an inverse analysis based on a database fed by massively automated finite element simulations. Experimental data are extracted from load-displacement indentation curves as well as indentation imprints measured by Scanning Probe Microscopy (SPM). We use this methodology to study plasticity of various MG compositions: Zr, Mg, Pd, Fe, La and measure their pressure sensitivity and yield stress. We also discuss the influence of plastic flow rule, contact friction, 3D effects and tip deflection on the results of our methodology. Results are then put in prospect using a wider range of materials such as crystalline metals on which we apply the same inverse method