Probability Mechanisms Map of Dislocation-obstacle Interaction as an Enabler of Physics-based Multiscale Modeling on Precipitation Hardening

Structural materials’ mechanical properties are largely controlled by the evolutions and interactions of their inside microstructural features called defects. In particular, the interaction between line defects (known as dislocations) and other obstacles (e.g. impurity precipitates) is playing a decisive role. Multiscale materials modeling (MMM), as a widely adopted strategy over the past few decades, has provided unprecedented details on defect’s evolutions and interactions from the atomic level. However, in the current MMM paradigm, significant gap still exists on transferring fundamental mechanisms of local dislocation-obstacle interaction into a predictive global constitutive relationship. The objective of this proposal is to develop a novel modeling framework to probe the accessible transition pathways and uncover the competing atomistic interaction mechanisms for any given dislocation-obstacle pair. The project will establish a capability of quantifying the occurrence probability of each mechanism and its embedded uncertainty over broad thermo-mechanical parameter space covering the realistic timescales.