ToughMG · Modeling the fracture toughness of metallic glasses through a multiscale approach
Horizon 2020 — Marie Skłodowska-Curie Actions
- Duration
- 2021-10-01 → 2023-09-30
- EU contribution
- €196,708
- Participants
- 1
- Scheme
- MSCA-IF
Lines connect the coordinator with its partners.
Results in brief
Modeling the fracture toughness of metallic glasses through a multiscale approach
The elasto-plastic deformation of amorphous solids, glasses in particular, and their modes of failure, remain major challenges in mechanics and materials science, with far reaching fundamental and practical implications. At the fundamental level, the irreversible and failure dynamics of glasses pose deep questions about disordered, out-of-equilibrium, driven dissipative systems. Our understanding of failure pathways remains very incomplete and in particular, lags behind our understanding of the corresponding processes in the ordered counterparts of glasses, i.e., in crystalline solids. This research proposal aims to better understand the connection between amorphous microstructures and material resistance to failure. Main research objectives of this action are: (i) building a novel algorithm to detect the field of plastic instabilities in structural glasses, (ii) understanding the nonlinear micromechanics of glassy defects and extracting microscopic flow rules from glassy samples, and (iii) coupling particle based simulations and mesoscopic elasto-plastic models to study strain localization and fracture. Overall, this project has led to the development of new cutting edge microscopic tools that help us to characterize structural and mechanical heterogeneities in structural glasses. We have shown that one can firmly establish a link between microstructures and glassy defects. Furthermore, we have demonstrated that one can extract local flow rules from as-cast glassy samples. The latter opens new avenues including: (i) the systematic and efficient characterization of a large catalog of glasses with different chemical compositions and material preparation histories and (ii) the calibration of mesoscopic models of plasticity to study large scale dissipative collective phenomena, such as the nucleation of shear bands.
Data: CORDIS, © European Union
Project objective
Bulk metallic glasses (BMGs) are promising materials that combine the strength of metal alloys with the elasticity of glassy polymers. Compared to their crystalline counterpart, the lack of dislocations and grain boundaries translates into better energy restitution, excellent wear, and corrosion resistance, making them promising candidates for sports goods to biomedical materials. Unfortunately, BMGs are notorious for exhibiting crack growth, fracture, and, ultimately, catastrophic failure, severely limiting their applications. Recently, experimental observation showed that BMGs could exhibit a mechanical transition revealed by a sharp drop in fracture toughness (ability to resist failure in the presence of a crack) as a function of a protocol (fictive) temperature that controls the glass stability. This transition strongly echoes with the ductile to brittle transition seen in recent numerical and theoretical works and is found to be linked to a sharp decrease in plastic defects (soft spots), which play a role similar to dislocations in crystals.In this action, we propose investigating the toughening transition seen in BMGs through a novel multiscale numerical approach. This action aims to enable the parametrization of continuum models with the insight gained from microscopic simulations. In ToughMG, I will associate my experience in the detection and micromechanics of plastic defects at the microscopic level to the prominent expertise provided by Prof. Barrat and the host institution in modeling plasticity at the mesoscopic and macroscopic scale. The methodology developed will allow me to predict large scale plastic strain observed prior fracture as a function of the material's protocol history. This research plan can substantially advance our understanding of the connection between glassy structure and fracture mechanics of bulk metallic glasses and allows for better material design.
Original text from CORDIS.
Participants
- UNIVERSITE GRENOBLE ALPES · GrenobleCoordinatorFrance
Links
Data: CORDIS, © European Union