A Multiscale, Physics-Based Framework for Understanding Microcracking in Additively Manufactured Ni-Based Superalloys

Speaker: Mostafa Salem, Engineering Doctorate Student, University of Sheffield
Series: Engineering - Mechanics and Materials Seminar Series

The mitigation of microcracking in Ni-based superalloys during metal additive manufacturing (MAM) remains a longstanding challenge for both academia and industry. My research employs multiscale, multiphysics modelling approaches to investigate the underlying mechanisms responsible for microcrack initiation and evolution. First, a multicomponent phase-field solidification model is developed to predict the formation and spatial distribution of nanoscale voids within the interdendritic and intercellular regions of solidifying grains. These predictions are subsequently coupled with a diffusion-assisted damage evolution model incorporating crystal plasticity, identifying stress-assisted diffusion at elevated temperatures as the principal mechanism driving microcrack formation. Finally, a coupled thermomechanical framework is employed to connect microscale residual stress development and damage evolution with their meso- and macroscale counterparts.