Alex Mamaev: Phase-field crystal modeling of precipitation in binary alloys

Vortragender/Speaker: Alex Mamaev, PhD (Institute für Wissenschaftliches Rechnen, TU-Dresden)
Ansprechpartner/Contact: Prof. Dr. Marco Salvalaglio

Titel/Title:
Phase-field crystal modeling of precipitation in binary alloys

Zusammenfassung/Abstract:
Phase-field crystal (PFC) models provide a continuum description of crystalline materials that retains atomic-scale structure while evolving on diffusive time scales. This makes PFC well positioned for studying elastoplastic phenomena and their influence on nanometer-scale phase transformations. In this seminar, I will present a novel binary alloy PFC model aimed at improving quantitative control over its free energy landscape, including the depths and curvatures of free energy wells and the inclusion of additional solid phases. This model also incorporates a spatially varying and temperature-dependent mobility, analogous to traditional phase-field models, allowing for effects such as enhanced grain boundary diffusion. Using this framework, I will first examine deformation-assisted precipitation, where I will show how the Avrami behavior develops a second, plasticity induced timescale. Next, I will discuss lamellar precipitation in the limits of surface and volume-dominated diffusion, showing agreement with classical steady-state growth theories in a time-averaged sense, alongside time-dependent behavior driven by coherency strain accumulation and dislocation nucleation. I will conclude with ongoing work toward quantitatively matched PFC models, with the goal of extending PFC approaches toward predictive modeling of alloy phase transformations.