This presentation provides an overall modeling framework encompassing fast-acting physics-based method to predict the formation of defects in additively manufactured component produced by laser powder bed fusion process (LPBF). The instability and subsequent balling, unstable key holing and lack of fusion have been modeled using primarily energy conservation, the effect of temperature dependent surface tension coefficient and Marangoni convection. The analytical model predicts temperature field to resolve melt pool details and then is extended beyond single track to predict formation of defects in multilayer deposit. The defects types and position have been defined and evaluated and used to construct process maps for different metals and alloys. Marangoni convection has been used to resolve defect related to Raleigh-Ritz instability and subsequent balling that can cause porosity due to layer thickness variation. Part level experiments are also carried out to validate the model capability to predict defect location in additively manufactured part.
- Understand the origin of defects generated in AM processes and how to reduce them or eliminate them
- Define the methods to additively fabricated defect free parts
- Understand the major parameters that lead to defects generation
Why Is It Important?
This presentation discuss models developed for 3D prediction of defects in powder bed fusion process. The prediction is important as we can generate defects-free process maps.