Numerical Simulation of Effect of Different Initial Morphologies on Melt Hydrodynamics in Laser Polishing of Ti6Al4V
As a surface finishing technique for rapid remelting and re-solidification, laser polishing can effectively eliminate the asperities so as to approach the feature size. Nevertheless, the polished surface quality is significantly sensitive to the processing parameters, especially with respect to melt...
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| Format: | Article |
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MDPI AG
2021-05-01
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| Series: | Micromachines |
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| Online Access: | https://www.mdpi.com/2072-666X/12/5/581 |
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| author | Kai Li Zhenyu Zhao Houming Zhou Hao Zhou Jie Yin Wei Zhang Guiyao Zhou |
| author_facet | Kai Li Zhenyu Zhao Houming Zhou Hao Zhou Jie Yin Wei Zhang Guiyao Zhou |
| author_sort | Kai Li |
| collection | DOAJ |
| description | As a surface finishing technique for rapid remelting and re-solidification, laser polishing can effectively eliminate the asperities so as to approach the feature size. Nevertheless, the polished surface quality is significantly sensitive to the processing parameters, especially with respect to melt hydrodynamics. In this paper, a transient two-dimensional model was developed to demonstrate the molten flow behavior for different surface morphologies of the Ti6Al4V alloy. It is illustrated that the complex evolution of the melt hydrodynamics involving heat conduction, thermal convection, thermal radiation, melting and solidification during laser polishing. Results show that the uniformity of the distribution of surface peaks and valleys can improve the molten flow stability and obtain better smoothing effect. The high cooling rate of the molten pool resulting in a shortening of the molten lifetime, which prevents the peaks from being removed by capillary and thermocapillary forces. It is revealed that the mechanism of secondary roughness formation on polished surface. Moreover, the double spiral nest Marangoni convection extrudes the molten to the outsides. It results in the formation of expansion and depression, corresponding to nearby the starting position and at the edges of the polished surface. It is further found that the difference between the simulation and experimental depression depths is only about 2 μm. Correspondingly, the errors are approximately 8.3%, 14.3% and 13.3%, corresponding to Models 1, 2 and 3, respectively. The aforementioned results illustrated that the predicted surface profiles agree reasonably well with the experimentally measured surface height data. |
| first_indexed | 2024-03-10T11:14:41Z |
| format | Article |
| id | doaj.art-eae49ae7df0648f0b0b8b59389527c2a |
| institution | Directory Open Access Journal |
| issn | 2072-666X |
| language | English |
| last_indexed | 2024-03-10T11:14:41Z |
| publishDate | 2021-05-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Micromachines |
| spelling | doaj.art-eae49ae7df0648f0b0b8b59389527c2a2023-11-21T20:32:34ZengMDPI AGMicromachines2072-666X2021-05-0112558110.3390/mi12050581Numerical Simulation of Effect of Different Initial Morphologies on Melt Hydrodynamics in Laser Polishing of Ti6Al4VKai Li0Zhenyu Zhao1Houming Zhou2Hao Zhou3Jie Yin4Wei Zhang5Guiyao Zhou6School of Intelligent Manufacturing and Equipment, Shenzhen Institute of Information Technology, Shenzhen 518172, ChinaSchool of Intelligent Manufacturing and Equipment, Shenzhen Institute of Information Technology, Shenzhen 518172, ChinaSchool of Mechanical Engineering, Xiangtan University, Xiangtan 411105, ChinaSchool of Intelligent Manufacturing and Equipment, Shenzhen Institute of Information Technology, Shenzhen 518172, ChinaSchool of Intelligent Manufacturing and Equipment, Shenzhen Institute of Information Technology, Shenzhen 518172, ChinaSchool of Intelligent Manufacturing and Equipment, Shenzhen Institute of Information Technology, Shenzhen 518172, ChinaGuangdong Provincial Key Laboratory of Nanophotonic Functional Materials and Devices, South China Normal University, Guangzhou 510006, ChinaAs a surface finishing technique for rapid remelting and re-solidification, laser polishing can effectively eliminate the asperities so as to approach the feature size. Nevertheless, the polished surface quality is significantly sensitive to the processing parameters, especially with respect to melt hydrodynamics. In this paper, a transient two-dimensional model was developed to demonstrate the molten flow behavior for different surface morphologies of the Ti6Al4V alloy. It is illustrated that the complex evolution of the melt hydrodynamics involving heat conduction, thermal convection, thermal radiation, melting and solidification during laser polishing. Results show that the uniformity of the distribution of surface peaks and valleys can improve the molten flow stability and obtain better smoothing effect. The high cooling rate of the molten pool resulting in a shortening of the molten lifetime, which prevents the peaks from being removed by capillary and thermocapillary forces. It is revealed that the mechanism of secondary roughness formation on polished surface. Moreover, the double spiral nest Marangoni convection extrudes the molten to the outsides. It results in the formation of expansion and depression, corresponding to nearby the starting position and at the edges of the polished surface. It is further found that the difference between the simulation and experimental depression depths is only about 2 μm. Correspondingly, the errors are approximately 8.3%, 14.3% and 13.3%, corresponding to Models 1, 2 and 3, respectively. The aforementioned results illustrated that the predicted surface profiles agree reasonably well with the experimentally measured surface height data.https://www.mdpi.com/2072-666X/12/5/581laser polishingdifferent surface morphologiesmelt hydrodynamicsnumerical simulation |
| spellingShingle | Kai Li Zhenyu Zhao Houming Zhou Hao Zhou Jie Yin Wei Zhang Guiyao Zhou Numerical Simulation of Effect of Different Initial Morphologies on Melt Hydrodynamics in Laser Polishing of Ti6Al4V Micromachines laser polishing different surface morphologies melt hydrodynamics numerical simulation |
| title | Numerical Simulation of Effect of Different Initial Morphologies on Melt Hydrodynamics in Laser Polishing of Ti6Al4V |
| title_full | Numerical Simulation of Effect of Different Initial Morphologies on Melt Hydrodynamics in Laser Polishing of Ti6Al4V |
| title_fullStr | Numerical Simulation of Effect of Different Initial Morphologies on Melt Hydrodynamics in Laser Polishing of Ti6Al4V |
| title_full_unstemmed | Numerical Simulation of Effect of Different Initial Morphologies on Melt Hydrodynamics in Laser Polishing of Ti6Al4V |
| title_short | Numerical Simulation of Effect of Different Initial Morphologies on Melt Hydrodynamics in Laser Polishing of Ti6Al4V |
| title_sort | numerical simulation of effect of different initial morphologies on melt hydrodynamics in laser polishing of ti6al4v |
| topic | laser polishing different surface morphologies melt hydrodynamics numerical simulation |
| url | https://www.mdpi.com/2072-666X/12/5/581 |
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