Phase-field microstructure simulation during aluminum alloy friction surfacing

Numerical simulation of microstructure can be considered as an effective way to understand microstructural developments during friction surfacing better. In this study, the results of temperature and strain rate required for simulation of recrystallization and grain growth during friction surfacing were obtained using a 3D finite element model of friction surfacing process. Then, the microstructure of AA2024 aluminum alloy coating was predicted using two multiphase-field (MPFM) and dislocation density-based constitutive material models. The results showed that as the traverse speed increases, the strain rate and temperature increase, but the maximum strain-rate region decreases. Also, the incubation time before recrystallization decreases from 0.3 s to 0.21 s by increasing traverse speed from 75 mm/min to 125 mm/min. However, as the traverse speed increases from 75 mm/min to 125 mm/min, the recrystallization time decreases from 0.11 s to 0.09 s. As the traverse speed increases, the recrystallization time contribution increases over the total time of deformation during friction surfacing, and as a result, the recrystallization efficiency increases. A comparison of predicted microstructure and grain size measured by optical microscopy showed that the models used in this study can predict grain size with a maximum error of 10%.