| About this Abstract |
| Meeting |
Materials Science & Technology 2020
|
| Symposium
|
Additive Manufacturing: Equipment, Instrumentation and Measurement
|
| Presentation Title |
Dynamics of Laser-powder-metal Interactions in L-PBF Captured by High Speed Imaging |
| Author(s) |
Manyalibo Matthews, Nicholas Calta, Philip Depond, Gabe Guss, Saad Khairallah, Jonathan Lee, Aiden Martin, Rongpei Shi, Maria Strantza, Alexander Rubenchik |
| On-Site Speaker (Planned) |
Manyalibo Matthews |
| Abstract Scope |
In laser powder bed fusion (LPBF) additive manufacturing, complex hydrodynamics driven by vapor recoil and Marangoni convection lead to liquid metal interfaces that are steeply curved thereby affecting laser-material coupling efficiency. Changes in dynamic absorptivity due to melt pool motion can lead to fluctuations in local microstructure and residual stress. To clarify the complex physics involved, a LPBF test bed equipped with high speed optical imaging and microcalorimetry is used to study melt pool dynamics as a function of laser parameters for several commercial-grade alloy systems. To capture keyhole dynamics, a second testbed is used at synchrotron beamlines for high speed x-ray radiography. Hydrodynamic finite element models simulate the melt pool morphology and dynamics, providing insight into energy coupling, keyholing and spatter generation mechanisms. The combination of unique diagnostics and high-fidelity modeling creates an exceptional capability for L-PBF physics validation and process optimization. Prepared by LLNL under Contract DE-AC52-07NA27344. |