Additive Manufacturing process simulation for metal laser powder bed fusion has achieved a degree of mainstream status in recent years. It is however, still with significant limitations. One major limitation is the inability to deliver meso-scale results, on a full part scale, in a reasonable calculation time. It has been estimated that running a complete part at the individual scan vector level would require millennia to solve.
The present work describes a novel multi-scale process simulation approach that enables thermal history and defect prediction at the individual scan vector and powder layer level in minutes. Developed in-house by a major aerospace company, the approach has been thoroughly validated, and is in production use today. The model is able to predict risk of local defects including keyholing, lack of fusion, balling up, and surface roughness. Further it can determine the process parameter window locally for any location within the part, based on the local geometry and temperature of the substrate before the laser is applied locally. The analysis also includes probabilistic effects and supports uncertainty quantification.
Once incorporated into a commercial software platform, this solution will enable engineers to evaluate the build and risk of defects given the proposed process parameters, or even to define how process parameters and scan vectors need to be modified locally to mitigate risk. It will also enable identification of high risk areas when inspection needs to focus and generally support the emerging field of “virtual certification”.
Learning Objectives:
- Describe how the presented simulation approach will enable a detailed evaluation of a build including the risk of keyholing, lack of fusion, balling-up, and surface roughness.
- Ideate how the simulation tool will enable rapid qualification and design for additive
- Describe how the simulation tool can be used to identify the best process parameter set for a given region within the geometry, at the individual scan vector, and powder layer.
