Powder-based additive manufacturing processes
Powder-based additive manufacturing processes are promising large-scale additive manufacturing (or 3D printing) techniques that allow for rapid layer-upon-layer production of prototypes, and lately for weight-sensitive/multi-functional parts at small volumes, with almost arbitrary complexity.
These processes provide several advantages compared to conventional manufacturing techniques, such as greater design freedom, mass customisation and personalisation of products, production of complex geometries to improve performance and reduce labour costs, decreased wastage of precious materials, and new business models and supply chains. However, several challenges also exist. For example, a lack of understanding of the impact of grain characteristics on the underlying physical processes has forced the industry to only use powders with a very narrow range of grain characteristics (e.g. size and shape distribution). Such stringent requirements increase the cost of powder (raw material), which consequently increases the production cost and hinders the development of new processes and the introduction of new materials. To address this issue, we have developed high-quality research software for process simulation to complement experiments and to enable new scientific discoveries and innovations. For this purpose, in my group we use a wide range of high-fidelity numerical techniques including Discrete Element Method (DEM) for modelling powder flow, Lorenz-Mie theory for modelling heat transfer and lattice-Boltzmann to investigate the phase change processes.
Below you can see an animation of powder spreading process in EDEM Software Package generated during a joint collaboration:
Device-scale simulation of the Powder Bed Additive Manufacturing process. The powder characterisation data are directly included into the simulations:
Development of multi-scale, flow-particle simulation techniques.
Computational resources are the main concern in applying numerical techniques to the particulate flow systems. A hierarchical simulation strategy is often employed to achieve a comprehensive description of such systems. My team actively works across all scales to provide a better understanding of particle-laden flows systems.
We have recently used such techniques to investigate the role of particle impacts in erosion in flow systems. To this end we have developed a multiphysics solver capable of dealing with particle-flow interaction and collision (DEM and lattice-Boltzmann methods) while directly capturing the materials damage at mesoscales using the Peridynamics theory.