Multi-material modelling for selective laser melting

Abstract

Selective Laser Melting (SLM) is a powder-bed Additive Manufacturing (AM) process which uses a laser beam to fully melt the powders layer upon layer to build a 3D part. While most studies are conducted on SLM using single material, the application of multi-materials using this technology can offer more advantages than the conventional manufacturing methods. Complex multi-materials parts can be built which conventional manufacturing methods are unable to due to their restriction in design of freedom. However, the SLM process has its own limitations in producing multi-material parts. Since SLM uses a powder bed to build parts, the use of different powder materials in the powder bed will result in contamination of the unused powder, rendering unnecessary wastages. Therefore, using modelling techniques to attain the optimized parameters before conducting the actual experiment to verify its validity will aid in reducing wastages, leading to cost saving. To study the effects of the interface of different materials during the laser scanning, a model was simulated to observe the melting process. An open-source LAMMPS (Large-scale Atomic Molecular Massively Parallel Simulator) software uses Molecular Dynamics (MD) to simulate the melting process. The materials used for the simulations are iron (FE) and aluminum (Al). The modelling is extended to multiple layers to allow the observation of the bonding between layers.