Residual Heat Effect on the Melt Pool Geometry during the Laser Powder Bed Fusion Process
Abstract
:1. Introduction
2. Experimental Approach
3. Numerical Approach
3.1. Discrete Element Method
3.2. Thermo-Fluid Simulation
4. Results and Discussion
4.1. Experimental Results
4.1.1. Surface Measurements
4.1.2. Metallography
4.2. Numerical Results
4.2.1. Multi-Track Results
4.2.2. Multi-Layer Results
5. Conclusions
- The transverse melt pool boundary obtained from the laser-turn region showed a significant overlap between the tracks, both in the experiment and simulation. The numerical analysis showed that the overlap was due to the merging of the melt pools from the two successive tracks. Besides, the overlap region was significantly higher for a 0.5 mm scan length compared to 1 mm.
- The hatch spacing also had a significant effect on the formation of the subsequent melt pool boundary due to the presence of residual heat. Apart from the increase in the overlap, the depth of the melt pool increased significantly with lower hatch spacing.
- The surface profile of the first layer affected the actual powder layer thickness in the second layer, which in turn affected the second track formation in the second layer. The micrograph showed that the gap between the two-layer boundaries was higher for the region with a higher first-layer surface height.
6. Future Work
Author Contributions
Funding
Data Availability Statement
Conflicts of Interest
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Factor | Value |
---|---|
Laser Power (W) | 195 |
Laser spot size (µm) | 100 |
Scan speed (mm/s) | 375, 750, 1500 |
Hatch spacing (µm) | 80, 120 |
Scan length (mm) | 0.5, 1, 1.5 |
Parameters | Values |
---|---|
Solidus temperature, TS | 1563 K |
Liquidus temperature, TL | 1623 K |
Boiling temperature, Tv | 3188 K |
Viscosity | 0.007 kg/m/s |
Surface tension | 1.8 N/m |
Surface tension gradient | −2 × 10−5 N/m/K |
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Shrestha, S.; Chou, K. Residual Heat Effect on the Melt Pool Geometry during the Laser Powder Bed Fusion Process. J. Manuf. Mater. Process. 2022, 6, 153. https://doi.org/10.3390/jmmp6060153
Shrestha S, Chou K. Residual Heat Effect on the Melt Pool Geometry during the Laser Powder Bed Fusion Process. Journal of Manufacturing and Materials Processing. 2022; 6(6):153. https://doi.org/10.3390/jmmp6060153
Chicago/Turabian StyleShrestha, Subin, and Kevin Chou. 2022. "Residual Heat Effect on the Melt Pool Geometry during the Laser Powder Bed Fusion Process" Journal of Manufacturing and Materials Processing 6, no. 6: 153. https://doi.org/10.3390/jmmp6060153
APA StyleShrestha, S., & Chou, K. (2022). Residual Heat Effect on the Melt Pool Geometry during the Laser Powder Bed Fusion Process. Journal of Manufacturing and Materials Processing, 6(6), 153. https://doi.org/10.3390/jmmp6060153