About this Abstract |
Meeting |
2021 Annual International Solid Freeform Fabrication Symposium (SFF Symp 2021)
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Symposium
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Materials
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Presentation Title |
Metal Additive Manufacturing with Bessel Beams |
Author(s) |
Thej Tumkur, Sheldon Wu, John D Roehling, Tien T Roehling, Rongpei Shi, Saad A. Khairallah, Gabe Guss, Michael F Crumb, Manyalibo J Matthews |
On-Site Speaker (Planned) |
Thej Tumkur |
Abstract Scope |
Metal additive manufacturing (AM) often results in defects, pores and columnar grains, leading to poor mechanical properties. Here, we show that a tailored spatial intensity distribution of the process laser, in the form of Bessel beams, enables microstructural control and leads to superior mechanical properties of 3D printed metals. Bessel beams are nondiffractive and propagate with longer depth of foci than conventional beams. In our experiments with stainless steel, post-mortem analysis of tracks and full builds produced using Bessel beams reveals grain refinement and larger melt pool volumes (in comparison to Gaussian beams). Highspeed imaging also reveals longer melt pool solidification times, which correlates to a greater propensity for equiaxed grain formation, as corroborated by high-fidelity powder-scale modeling of the melt pool dynamics. We will discuss the significance of our results and show that Bessel beams hold the potential to revolutionize metal AM.
Prepared by LLNL under Contract DE-AC52-07NA27344. |
Proceedings Inclusion? |
Definite: Post-meeting proceedings |