|About this Abstract
||2018 TMS Annual Meeting & Exhibition
||Phase Transformations and Microstructural Evolution
||Phase-field Modeling of Widmanstätten Growth
||Hocine Lebbad, Benoît Appolaire, Alphonse Finel, Yann Le Bouar
|On-Site Speaker (Planned)
Widmanstätten structures are observed in many metallic alloys (FeC, Ti alloys ...). These acicular structures often develop in colonies from former grain boundaries following a particular growth kinetic linear in time at fixed temperature. They lower toughness and resistance to fatigue, making it crucial to understand precisely their growth mechanisms. Among many open issues, the analytical description of a parabolic tip growth driven by diffusion lacks to predict, for a given supersaturation, both the tip radius R and the growth velocity V.
A phase-field model coupling both chemical and elastic effects has first been developed. The crystallographic change of the phase transformation implies a significant anisotropy of the elastic energy whose role on the growth has been investigated. We have observed that the tip shape and radius are independent of the dynamical growth process, providing us a new criterion to predict R and V. Viscoplasticity effects have also been modeled.
||Planned: Supplemental Proceedings volume