Predicting the Properties of Additive Parts: Powder-bed and Wire-arc Processes

Metal Additive Manufacturing (AM) technologies enable the production of near-net-shape components using 3D computer aided design (CAD) data. These processes have the potential to significantly reduce material wastage, energy usage and component lead times whilst enabling light-weight designs and integrated assemblies to be produced that could not be otherwise built using conventional manufacturing methods or without extensive welding for fabrication. In this presentation, two AM techniques are considered: selective laser melting (SLM) – a laser powder-bed fusion process, and wire-arc additive manufacturing (WA-AM) – an open architecture additive process using conventional arc welding systems with robotic control and manipulation of the torch.

One of the key challenges is to understand the mechanical performance of AM parts. The layer-by-layer nature of AM processes introduces an almost unique thermal history at each location within the part. As a consequence, strong microstructural anisotropy and location-dependent material properties are features of as-built AM components. The ability to accurately simulate and predict the distortion, residual stress and microstructural features that arise from AM processes is critical to the certification of AM parts and establishing AM as a robust and reliable manufacturing route.

In this presentation, Dassault Systemes’ 3DX Additive Manufacturing 2017x Application (using new features in the Abaqus solver) are used to perform thermo-mechanical-metallurgical simulations of parts produced using SLM and WA-AM. The predictions are validated against experimental measurements of temperature transients, distortion measurements, and metallographic examination, thereby demonstrating the potential that these new modelling methods have to enhance the assessment of AM part performance.