Microstructure and Superior Corrosion Resistance of an In-Situ Synthesized NiTi-Based Intermetallic Coating via Laser Melting Deposition
A nickel–titanium (NiTi)-based intermetallic coating was in-situ synthesized on a Ti–6Al–4V (TC4) substrate via laser melting deposition (LMD) using Ni–20Cr and TC4 powders. Scanning electron microscopy, X-ray diffraction, a digital microhardness tester and an electrochemical analyzer were used to e...
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MDPI AG
2022-02-01
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| Series: | Nanomaterials |
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| Online Access: | https://www.mdpi.com/2079-4991/12/4/705 |
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| author | Cheng Deng Menglong Jiang Di Wang Yongqiang Yang Vyacheslav Trofimov Lianxi Hu Changjun Han |
| author_facet | Cheng Deng Menglong Jiang Di Wang Yongqiang Yang Vyacheslav Trofimov Lianxi Hu Changjun Han |
| author_sort | Cheng Deng |
| collection | DOAJ |
| description | A nickel–titanium (NiTi)-based intermetallic coating was in-situ synthesized on a Ti–6Al–4V (TC4) substrate via laser melting deposition (LMD) using Ni–20Cr and TC4 powders. Scanning electron microscopy, X-ray diffraction, a digital microhardness tester and an electrochemical analyzer were used to evaluate the microstructure, Vicker’s microhardness and electrochemical corrosion resistance of the intermetallic coating. Results indicate that the microstructure of the intermetallic coating is composed of NiTi<sub>2</sub>, NiTi and Ni<sub>3</sub>Ti. The measured microhardness achieved is as high as ~850 HV<sub>0.2</sub>, ~2.5 times larger than that of the TC4 alloy, which can be attributed to the solid solution strengthening of Al and Cr, dispersion strengthening of the intermetallic compounds, and grain refinement strengthening from the rapid cooling of LMD. During the electrochemical corrosion of 3.5% NaCl solution, a large amount of Ti ions were released from the intermetallic coating surface and reacted with Cl<sup>−</sup> ions to form [TiCl<sub>6</sub>]<sup>2</sup> with an increase in corrosion voltage. In further hydrolysis reactions, TiO<sub>2</sub> formation occurred when the ratio of [TiCl<sub>6</sub>]<sup>2−</sup> reached a critical value. The in-situ synthesized intermetallic coating can achieve a superior corrosion resistance compared to that of the TC4 alloy. |
| first_indexed | 2024-03-09T21:19:01Z |
| format | Article |
| id | doaj.art-8bc3971d274346d0b5a055c3e26f764f |
| institution | Directory Open Access Journal |
| issn | 2079-4991 |
| language | English |
| last_indexed | 2024-03-09T21:19:01Z |
| publishDate | 2022-02-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Nanomaterials |
| spelling | doaj.art-8bc3971d274346d0b5a055c3e26f764f2023-11-23T21:26:46ZengMDPI AGNanomaterials2079-49912022-02-0112470510.3390/nano12040705Microstructure and Superior Corrosion Resistance of an In-Situ Synthesized NiTi-Based Intermetallic Coating via Laser Melting DepositionCheng Deng0Menglong Jiang1Di Wang2Yongqiang Yang3Vyacheslav Trofimov4Lianxi Hu5Changjun Han6School of Mechanical and Automotive Engineering, South China University of Technology, Guangzhou 510641, ChinaSchool of Mechanical and Automotive Engineering, South China University of Technology, Guangzhou 510641, ChinaSchool of Mechanical and Automotive Engineering, South China University of Technology, Guangzhou 510641, ChinaSchool of Mechanical and Automotive Engineering, South China University of Technology, Guangzhou 510641, ChinaSchool of Mechanical and Automotive Engineering, South China University of Technology, Guangzhou 510641, ChinaSchool of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001, ChinaSchool of Mechanical and Automotive Engineering, South China University of Technology, Guangzhou 510641, ChinaA nickel–titanium (NiTi)-based intermetallic coating was in-situ synthesized on a Ti–6Al–4V (TC4) substrate via laser melting deposition (LMD) using Ni–20Cr and TC4 powders. Scanning electron microscopy, X-ray diffraction, a digital microhardness tester and an electrochemical analyzer were used to evaluate the microstructure, Vicker’s microhardness and electrochemical corrosion resistance of the intermetallic coating. Results indicate that the microstructure of the intermetallic coating is composed of NiTi<sub>2</sub>, NiTi and Ni<sub>3</sub>Ti. The measured microhardness achieved is as high as ~850 HV<sub>0.2</sub>, ~2.5 times larger than that of the TC4 alloy, which can be attributed to the solid solution strengthening of Al and Cr, dispersion strengthening of the intermetallic compounds, and grain refinement strengthening from the rapid cooling of LMD. During the electrochemical corrosion of 3.5% NaCl solution, a large amount of Ti ions were released from the intermetallic coating surface and reacted with Cl<sup>−</sup> ions to form [TiCl<sub>6</sub>]<sup>2</sup> with an increase in corrosion voltage. In further hydrolysis reactions, TiO<sub>2</sub> formation occurred when the ratio of [TiCl<sub>6</sub>]<sup>2−</sup> reached a critical value. The in-situ synthesized intermetallic coating can achieve a superior corrosion resistance compared to that of the TC4 alloy.https://www.mdpi.com/2079-4991/12/4/705laser melting depositionnickel–titanium coatingin-situ synthesiscorrosion resistance |
| spellingShingle | Cheng Deng Menglong Jiang Di Wang Yongqiang Yang Vyacheslav Trofimov Lianxi Hu Changjun Han Microstructure and Superior Corrosion Resistance of an In-Situ Synthesized NiTi-Based Intermetallic Coating via Laser Melting Deposition Nanomaterials laser melting deposition nickel–titanium coating in-situ synthesis corrosion resistance |
| title | Microstructure and Superior Corrosion Resistance of an In-Situ Synthesized NiTi-Based Intermetallic Coating via Laser Melting Deposition |
| title_full | Microstructure and Superior Corrosion Resistance of an In-Situ Synthesized NiTi-Based Intermetallic Coating via Laser Melting Deposition |
| title_fullStr | Microstructure and Superior Corrosion Resistance of an In-Situ Synthesized NiTi-Based Intermetallic Coating via Laser Melting Deposition |
| title_full_unstemmed | Microstructure and Superior Corrosion Resistance of an In-Situ Synthesized NiTi-Based Intermetallic Coating via Laser Melting Deposition |
| title_short | Microstructure and Superior Corrosion Resistance of an In-Situ Synthesized NiTi-Based Intermetallic Coating via Laser Melting Deposition |
| title_sort | microstructure and superior corrosion resistance of an in situ synthesized niti based intermetallic coating via laser melting deposition |
| topic | laser melting deposition nickel–titanium coating in-situ synthesis corrosion resistance |
| url | https://www.mdpi.com/2079-4991/12/4/705 |
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