Understanding the interaction between complex thermal fields and metallic structures at the meso-scale is crucial for the prediction of microstructural evolution during thermomechanical processing. The competitive growth of crystal grains, driven by thermodynamic forces at the grain boundaries, is one of the most fundamental phenomena in metallurgy and solid state physics. The presence of second phase particles, which act as pinning sites for boundaries, drastically alters the coarsening behaviour of the system; particularly when considering that these particles have dierent thermal properties to the primary phase. In this work a multi-phase eld model, incorporating thermal gradient and curvature driving forces, is used to predict grain growth in a Ti6Al4V alloy system with second phase particle inclusions representative of oxide and carbide precipitates. The multi-phase eld framework is fully coupled to the heat equation. The incorporation of the thermal gradient driving force enables the detailed behaviour of the grain boundaries around the particles to be predicted. It is shown that the inclusion of particles with a lower thermal conductivity has a signicant inuence on the coarsening behaviour of various systems of grains, due to the combined eects of thermal shielding and the generation of thermal gradient driving forces between the boundaries and pinning particles.
|Publication status||Published - 5 Dec 2019|
Research Beacons, Institutes and Platforms
- Dalton Nuclear Institute