Extreme Scale Phase-Field Simulation of Sintering Processes

The sintering process, which turns loose powders into dense materials, is naturally found in the formation of glaciers, but is also the indispensable process to manufacture ceramic materials. The dynamically evolving microstructure, which is established during this process, largely influences the resulting material properties. To investigate this complex three- dimensional, scale-bridging evolution in realistic domain sizes, a highly optimized and parallelized multiphysics phase-field solver is developed. The solver is optimized in a holistic way, from the application level over the time integration and parallelization, down to the hardware. Optimizations include communication hiding, explicit vectorization, implicit schemes and local reduction of degrees of freedom. With this, we are able to investigate large- scale, three-dimensional domains and long integration times. We have achieved a single-core peak performance of 32.5%, scaled up to 172 032 cores on Hazel Hen, and simulated a multi-million particle system.