Effect of Laser Scanning Speed and Fine Shot Peening on Pore Characteristics, Hardness, and Residual Stress of Ti-6Al-4V Fabricated by Laser Powder Bed Fusion
There is a concern regarding sub-surface pores within laser powder bed fusion of Ti-6Al-4V, which can initiate cracks and reduce mechanical properties, especially after machining for surface finishing. This study investigated the effect of laser scanning speed and fine shot peening on the pore chara...
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MDPI AG
2024-02-01
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| Series: | Metals |
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| Online Access: | https://www.mdpi.com/2075-4701/14/2/250 |
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| author | Kanawat Ratanapongpien Anak Khantachawana Katsuyoshi Kondoh |
| author_facet | Kanawat Ratanapongpien Anak Khantachawana Katsuyoshi Kondoh |
| author_sort | Kanawat Ratanapongpien |
| collection | DOAJ |
| description | There is a concern regarding sub-surface pores within laser powder bed fusion of Ti-6Al-4V, which can initiate cracks and reduce mechanical properties, especially after machining for surface finishing. This study investigated the effect of laser scanning speed and fine shot peening on the pore characteristics, hardness, and residual stress of Ti-6Al-4V fabricated by laser powder bed fusion using scanning electron microscopy, X-ray micro-computed tomography, Vickers hardness, and X-ray diffraction. As the laser scanning speed increased, the number of pores and pore size increased, which reduced the hardness of Ti-6Al-4V. Most pores were less than 20 µm in size and randomly distributed. The fine shot peening generated plastic deformation and compressive residual stress on the surface, leading to higher hardness, with similar surface properties at all scanning speeds. The depth of compressive residual stress by fine shot peening varied corresponding to the scanning speeds. Increasing the scanning speed accelerated the rate of conversion between the compressive and tensile residual stresses, and decreased the depth of the maximum hardness by the fine shot peening from initial tensile residual stress within Ti-6Al-4V fabricated by laser powder bed fusion, thus reducing the enhancement achieved by the fine shot peening. |
| first_indexed | 2024-03-07T22:21:07Z |
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| id | doaj.art-a1fa0acfd30a4e24a2c20dced361e3ef |
| institution | Directory Open Access Journal |
| issn | 2075-4701 |
| language | English |
| last_indexed | 2024-03-07T22:21:07Z |
| publishDate | 2024-02-01 |
| publisher | MDPI AG |
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| series | Metals |
| spelling | doaj.art-a1fa0acfd30a4e24a2c20dced361e3ef2024-02-23T15:27:29ZengMDPI AGMetals2075-47012024-02-0114225010.3390/met14020250Effect of Laser Scanning Speed and Fine Shot Peening on Pore Characteristics, Hardness, and Residual Stress of Ti-6Al-4V Fabricated by Laser Powder Bed FusionKanawat Ratanapongpien0Anak Khantachawana1Katsuyoshi Kondoh2Department of Mechanical Engineering, King Mongkut’s University of Technology Thonburi (KMUTT), 126 PrachaUthit Rd., Bang Mod, ThungKhru, Bangkok 10140, ThailandDepartment of Mechanical Engineering, King Mongkut’s University of Technology Thonburi (KMUTT), 126 PrachaUthit Rd., Bang Mod, ThungKhru, Bangkok 10140, ThailandDepartment of Composite Materials Processing, Joining and Welding Research Institute, Osaka University, Ibaraki City 567-0047, JapanThere is a concern regarding sub-surface pores within laser powder bed fusion of Ti-6Al-4V, which can initiate cracks and reduce mechanical properties, especially after machining for surface finishing. This study investigated the effect of laser scanning speed and fine shot peening on the pore characteristics, hardness, and residual stress of Ti-6Al-4V fabricated by laser powder bed fusion using scanning electron microscopy, X-ray micro-computed tomography, Vickers hardness, and X-ray diffraction. As the laser scanning speed increased, the number of pores and pore size increased, which reduced the hardness of Ti-6Al-4V. Most pores were less than 20 µm in size and randomly distributed. The fine shot peening generated plastic deformation and compressive residual stress on the surface, leading to higher hardness, with similar surface properties at all scanning speeds. The depth of compressive residual stress by fine shot peening varied corresponding to the scanning speeds. Increasing the scanning speed accelerated the rate of conversion between the compressive and tensile residual stresses, and decreased the depth of the maximum hardness by the fine shot peening from initial tensile residual stress within Ti-6Al-4V fabricated by laser powder bed fusion, thus reducing the enhancement achieved by the fine shot peening.https://www.mdpi.com/2075-4701/14/2/250laser powder bed fusionfine shot peeningporeresidual stressTi-6Al-4V |
| spellingShingle | Kanawat Ratanapongpien Anak Khantachawana Katsuyoshi Kondoh Effect of Laser Scanning Speed and Fine Shot Peening on Pore Characteristics, Hardness, and Residual Stress of Ti-6Al-4V Fabricated by Laser Powder Bed Fusion Metals laser powder bed fusion fine shot peening pore residual stress Ti-6Al-4V |
| title | Effect of Laser Scanning Speed and Fine Shot Peening on Pore Characteristics, Hardness, and Residual Stress of Ti-6Al-4V Fabricated by Laser Powder Bed Fusion |
| title_full | Effect of Laser Scanning Speed and Fine Shot Peening on Pore Characteristics, Hardness, and Residual Stress of Ti-6Al-4V Fabricated by Laser Powder Bed Fusion |
| title_fullStr | Effect of Laser Scanning Speed and Fine Shot Peening on Pore Characteristics, Hardness, and Residual Stress of Ti-6Al-4V Fabricated by Laser Powder Bed Fusion |
| title_full_unstemmed | Effect of Laser Scanning Speed and Fine Shot Peening on Pore Characteristics, Hardness, and Residual Stress of Ti-6Al-4V Fabricated by Laser Powder Bed Fusion |
| title_short | Effect of Laser Scanning Speed and Fine Shot Peening on Pore Characteristics, Hardness, and Residual Stress of Ti-6Al-4V Fabricated by Laser Powder Bed Fusion |
| title_sort | effect of laser scanning speed and fine shot peening on pore characteristics hardness and residual stress of ti 6al 4v fabricated by laser powder bed fusion |
| topic | laser powder bed fusion fine shot peening pore residual stress Ti-6Al-4V |
| url | https://www.mdpi.com/2075-4701/14/2/250 |
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