Ultra-short pulsed laser powder bed fusion of Al-Si alloys: Impact of pulse duration and energy in comparison to continuous wave excitation
| Autor: | Tobias Ullsperger, Stefan Nolte, Lisa Schade, Hagen Kohl, Brian Seyfarth, Dongmei Liu, Gabor Matthäus, Markus Rettenmayr, Burak Yürekli, Roland Ramm |
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| Rok vydání: | 2021 |
| Předmět: |
0209 industrial biotechnology
Materials science business.industry Biomedical Engineering Pulse duration 02 engineering and technology 021001 nanoscience & nanotechnology Laser Fluence Industrial and Manufacturing Engineering law.invention Pulse (physics) Wavelength 020901 industrial engineering & automation law Fiber laser Continuous wave Optoelectronics General Materials Science 0210 nano-technology business Engineering (miscellaneous) Eutectic system |
| Zdroj: | Additive Manufacturing. 46:102085 |
| ISSN: | 2214-8604 |
| DOI: | 10.1016/j.addma.2021.102085 |
| Popis: | Laser assisted powder bed fusion of Al-40 wt%Si using ultra-short laser pulses is presented. The effects of the pulse duration as well as the pulse energy on the melt pool size, solidification morphology and material properties have been investigated. The experiments have been carried out with a mode-locked fiber laser system delivering pulses from 500 fs up to 800 ps at a wavelength of 1030 nm. Comparative investigations have been performed using a continuous wave Yb-fiber laser operating at 1070 nm. The results show that the melt pool width is reduced at shorter pulse durations and higher repetition rates while maintaining the same average power. Additionally, keyhole melting is achieved in pulsed operation after exceeding the threshold fluence for single pulse ablation. In comparison to continuous wave radiation, powder bed fusion using ultra-short laser pulses leads to a more uniform melt pool shape with refined primary Si and eutectic structure that is accompanied with an improvement of the mechanical properties. |
| Databáze: | OpenAIRE |
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