An Approach for the Microstructure-Sensitive Simulation of Shear-Induced Deformation and Recrystallization in Al-Si Alloys

Al alloys are known to experience extensive grain refinement during shear-assisted processing techniques, an effect driven by dynamic dislocation density generation and microstructural restoration assisted by deformation-induced heating. In order to predict the extent of grain refinement of Al-Si alloys in response to the friction-assisted shear deformation, a coupling of Finite Element Method and the Kinetic Monte Carlo Potts Model is utilized in this work. We show that our microstructure-sensitive model simulates the microstructural response of Al-Si alloys to influence of shear deformation and temperature, as a recrystallization and grain growth phenomenon. The microstructural evolution of Al-Si alloys was simulated as a function of deformation, temperature, and Si composition. Simulations were performed on microstructures representing alloy compositions corresponding to pure Al, Al-1 pct Si, and Al-4 pct Si, for temperatures ranging 300 degrees C to 400 degrees C and several different magnitudes of shear. Model predictions were validated with experimental results of the grain size and orientation changes in Al-Si alloys during pin-on-disk tribometer experiments. Further, these simulations predict that the increase in Si composition results in larger heterogeneities in strain distribution under shear and commensurately tepid recrystallization. This demonstrates a plausible physical explanation for variations in grain size observed in tribometric experiments.

Automated summary

In this work, a combination of Finite Element Method and the Kinetic Monte Carlo Potts Model is used to simulate the microstructural response of Al-Si alloys under friction-assisted shear deformation. The study reveals that an increase in Si composition leads to larger heterogeneities in strain distribution under shear and commensurately causes tepid recrystallization, providing a plausible physical explanation for variations in grain size observed in tribometric experiments.