Laser metal additive manufacturing (AM) requires precise coupling of energy to produce desired mechanical and morphological properties of printed structures. However, Gaussian-like process laser beams commonly employed in metal AM limit control over thermomechanical processes that govern microstructural and macroscale properties. In this talk, I will present our team’s efforts in using tailored spatial intensity profiles of the process laser beam, for improving control over melt pool dynamics. I will also discuss our efforts on implementing complex phase and polarization patterns for potentially greater degree of process control during metal 3D printing.  

5 THINGS YOU WILL LEARN DURING THIS SESSION:

1. Laser beam shaping can affect melt pool dynamics in metal AM
2. Shaping the amplitude of light can broaden the process window for conduction mode melting, mitigate spatter and reduce porosity
3.  Our initial observations lead to the question – can the polarization and phase of light be utilized to achieve greater control over melt pool dynamics?
4. We demonstrate shaping light in complex ways (amplitude, phase and polarization) can be used as an optical knob for controlling microstructure, but the intricacies of this observation is worthy of a debate/discussion! 
5. What other degrees of freedom of light can be used for process control during laser-based manufacturing? Kindly attend the talk to discuss further!

Thej Tumkur, Staff Scientist, Lawrence Livermore National Laboratory