About this Abstract |
Meeting |
MS&T21: Materials Science & Technology
|
Symposium
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Additive Manufacturing: Processing, Microstructure and Material Properties of Titanium-based Materials
|
Presentation Title |
An Infill Strategy for Eliminating Local Hot Spots in Ti64 Laser Powder Bed Fusion |
Author(s) |
Evan Diewald, Christian Gobert, Jack L Beuth |
On-Site Speaker (Planned) |
Jack L Beuth |
Abstract Scope |
In laser powder bed fusion (LPBF) porosity and inconsistent microstructure can be related to erratic thermal conditions caused, in part, by suboptimal infill scanning strategies. This talk presents an approach for reducing heat buildup in LPBF that can be implemented within most commercial machines. The “Powder Moat” strategy, where a thin wall is built outside the boundaries of the intended part, effectively eliminates in-plane hotspots by inducing a predictable delay after each raster. It also greatly reduces local melt pool geometric anomalies at raster ends. A semi-analytical model is used to generate process maps of delay times and moat thicknesses as a function of laser power and velocity for Ti64. The approach is validated through high speed imaging of melt pools in small portions of builds and through conventional infrared imaging of entire builds. This strategy allows for effective process planning based on melt pool dimensions derived from single beads. |