| Solidification front-particle interactions play an important role in Metal Matrix Composites (MMCs) manufacturing. The success of the interactions simulation hinges critically on the microscale solidification interfaces evolution and their interactions with particles.;The present thesis firstly validates a level-set based sharp interface finite-difference method with simple formulation and implementation against two-dimensional microscopic solvability theory for solidification of pure materials. The method is also shown to predict the correct physical behavior in the dendritic growth of impure materials.;Secondly, the methodology is advanced to account for the interaction between an evolving phase boundary and a particle placed in its path. In particular, the response of a growing dendrite to the presence of a particle embedded in the undercooled melt is studied in a limited parameter space. The results reveal that when particle to melt conductivity ratio lambda=k P/kL<1 the dendrite navigates around the particle and the particle pushing mode is not likely to happen.;The current method is further extended to study solidification front particle interactions of binary alloys. The directional solidification calculations are first validated against the Mullins-Sekerka stability theory and the stability spectrum is reproduced: The cellular front-particle interaction simulations show that the particle melt thermal conductivity ratio lambda, plays no role in determining the particle front interactions result. The species diffusion controls the phase front evolution around the particle. The solidification front avoids the particle and travels around it in the steepest solute gradient direction (independent of the thermal gradient). There is always a significant thickness of liquid present between the front and the particle as the front engulfs the particle. Therefore, it is difficult to envision a pushing type interaction between the front and the particle in binary alloy directional solidification.;Finally, by employing locally refined meshes where high curvature or steep gradients occur, significant speed-up of the current method is achieved without compromising accuracy. Thus, the work performed in this thesis has resulted in a computational framework for efficient computation of complex front-particle interactions in a sharp-interface setting. |
