Investigation of laser-induced plasma evolution in flexible pad laser shock forming with high speed camera
This study investigated the effect of plasma evolution, which dominates the forming load, on the fabrication of microcraters in flexible pad laser shock forming (FPLSF) using a high speed camera. It has been found that the plasma lifetime starting from plasma formation, expansion, decaying to vani...
| Main Authors: | , , , |
|---|---|
| Other Authors: | |
| Format: | Journal Article |
| Language: | English |
| Published: |
2015
|
| Subjects: | |
| Online Access: | https://hdl.handle.net/10356/104525 http://hdl.handle.net/10220/24649 |
| _version_ | 1826127738765836288 |
|---|---|
| author | Nagarajan, Balasubramanian Wang, Zhongke Castagne, Sylvie Zheng, Hongyu |
| author2 | School of Mechanical and Aerospace Engineering |
| author_facet | School of Mechanical and Aerospace Engineering Nagarajan, Balasubramanian Wang, Zhongke Castagne, Sylvie Zheng, Hongyu |
| author_sort | Nagarajan, Balasubramanian |
| collection | NTU |
| description | This study investigated the effect of plasma evolution, which dominates the forming load, on the fabrication
of microcraters in flexible pad laser shock forming (FPLSF) using a high speed camera. It has been
found that the plasma lifetime starting from plasma formation, expansion, decaying to vanishing was
less than 13.3 us at single pulse ablation, 350 times longer than the pulse duration. When 45 pulses were
applied as 5 cycles with 9 pulse train in each, the plasma size increased gradually to its maximum at
the fifth or sixth pulse. There was no interference between the plasma generated from each pulse. The
first pulse was sufficient for the fabrication of a crater. The crater depth and diameter increased only by
10% and 25% respectively at ablation with 45 pulses. At 45 pulses ablation for fluence from 7.3 J/cm2 to
20.9 J/cm2 in water confinement, the change factor appeared in descending sequence from laser fluence,
maximum plasma diameter, maximum plasma pressure, to crater depth by the order of 2.86, 2.18, 1.69
and 1.47 respectively. In glass, the plasma diameter increased by 3.28 times at increasing laser fluence.
The confined plasma in glass resulted in deeper craters. The smaller craters in water were attributed to
the forming load diminution due to the plasma expansion, shockwave attenuation in ablative overlay,
and the laser energy reduction. |
| first_indexed | 2024-10-01T07:13:26Z |
| format | Journal Article |
| id | ntu-10356/104525 |
| institution | Nanyang Technological University |
| language | English |
| last_indexed | 2024-10-01T07:13:26Z |
| publishDate | 2015 |
| record_format | dspace |
| spelling | ntu-10356/1045252023-03-04T17:20:54Z Investigation of laser-induced plasma evolution in flexible pad laser shock forming with high speed camera Nagarajan, Balasubramanian Wang, Zhongke Castagne, Sylvie Zheng, Hongyu School of Mechanical and Aerospace Engineering A*STAR SIMTech DRNTU::Engineering::Manufacturing This study investigated the effect of plasma evolution, which dominates the forming load, on the fabrication of microcraters in flexible pad laser shock forming (FPLSF) using a high speed camera. It has been found that the plasma lifetime starting from plasma formation, expansion, decaying to vanishing was less than 13.3 us at single pulse ablation, 350 times longer than the pulse duration. When 45 pulses were applied as 5 cycles with 9 pulse train in each, the plasma size increased gradually to its maximum at the fifth or sixth pulse. There was no interference between the plasma generated from each pulse. The first pulse was sufficient for the fabrication of a crater. The crater depth and diameter increased only by 10% and 25% respectively at ablation with 45 pulses. At 45 pulses ablation for fluence from 7.3 J/cm2 to 20.9 J/cm2 in water confinement, the change factor appeared in descending sequence from laser fluence, maximum plasma diameter, maximum plasma pressure, to crater depth by the order of 2.86, 2.18, 1.69 and 1.47 respectively. In glass, the plasma diameter increased by 3.28 times at increasing laser fluence. The confined plasma in glass resulted in deeper craters. The smaller craters in water were attributed to the forming load diminution due to the plasma expansion, shockwave attenuation in ablative overlay, and the laser energy reduction. Accepted version 2015-01-16T02:48:18Z 2019-12-06T21:34:30Z 2015-01-16T02:48:18Z 2019-12-06T21:34:30Z 2014 2014 Journal Article Nagarajan, B., Wang, Z., Castagne, S., & Zheng, H.Y. (2014). Investigation of laser-induced plasma evolution in flexible pad laser shock forming with high speed camera. Applied surface science, 308, 221-229. 0169-4332 https://hdl.handle.net/10356/104525 http://hdl.handle.net/10220/24649 10.1016/j.apsusc.2014.04.139 en Applied surface science © 2014 Elsevier B.V. This is the author created version of a work that has been peer reviewed and accepted for publication by Applied Surface Science, Elsevier B.V. It incorporates referee’s comments but changes resulting from the publishing process, such as copyediting, structural formatting, may not be reflected in this document. The published version is available at: [http://dx.doi.org/10.1016/j.apsusc.2014.04.139]. 24 p. application/pdf |
| spellingShingle | DRNTU::Engineering::Manufacturing Nagarajan, Balasubramanian Wang, Zhongke Castagne, Sylvie Zheng, Hongyu Investigation of laser-induced plasma evolution in flexible pad laser shock forming with high speed camera |
| title | Investigation of laser-induced plasma evolution in flexible pad laser shock forming with high speed camera |
| title_full | Investigation of laser-induced plasma evolution in flexible pad laser shock forming with high speed camera |
| title_fullStr | Investigation of laser-induced plasma evolution in flexible pad laser shock forming with high speed camera |
| title_full_unstemmed | Investigation of laser-induced plasma evolution in flexible pad laser shock forming with high speed camera |
| title_short | Investigation of laser-induced plasma evolution in flexible pad laser shock forming with high speed camera |
| title_sort | investigation of laser induced plasma evolution in flexible pad laser shock forming with high speed camera |
| topic | DRNTU::Engineering::Manufacturing |
| url | https://hdl.handle.net/10356/104525 http://hdl.handle.net/10220/24649 |
| work_keys_str_mv | AT nagarajanbalasubramanian investigationoflaserinducedplasmaevolutioninflexiblepadlasershockformingwithhighspeedcamera AT wangzhongke investigationoflaserinducedplasmaevolutioninflexiblepadlasershockformingwithhighspeedcamera AT castagnesylvie investigationoflaserinducedplasmaevolutioninflexiblepadlasershockformingwithhighspeedcamera AT zhenghongyu investigationoflaserinducedplasmaevolutioninflexiblepadlasershockformingwithhighspeedcamera |