Grain Refinement of Hypereutectic Immiscible Cu-50Cr Alloy during Rapid Melting and Solidification Induced by High Power Density Laser Beams
The microstructure of hypereutectic immiscible Cu-50Cr alloy (wt%) was effectively refined and homogenized by a high power density Nd:YAG continuous laser beam (power density 10<sup>4</sup>−10<sup>5</sup> MW/m<sup>2</sup>). The average grain size of Cr w...
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MDPI AG
2019-05-01
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| Series: | Metals |
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| Online Access: | https://www.mdpi.com/2075-4701/9/5/585 |
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| author | Litian Zhang Gang Yu Chongxin Tian Xiuli He Shaoxia Li |
| author_facet | Litian Zhang Gang Yu Chongxin Tian Xiuli He Shaoxia Li |
| author_sort | Litian Zhang |
| collection | DOAJ |
| description | The microstructure of hypereutectic immiscible Cu-50Cr alloy (wt%) was effectively refined and homogenized by a high power density Nd:YAG continuous laser beam (power density 10<sup>4</sup>−10<sup>5</sup> MW/m<sup>2</sup>). The average grain size of Cr was effectively refined from ~100 μm to ~1 μm, and some of the Cr particles even decreased to a few hundred nanometers. The high cooling rate (7.29 × 10<sup>6</sup> K/s) effectively inhibited the coarsening effect on Cr particles during liquid phase separation (LPS). The spherical Cr particles were preferably dispersed in the melt layer, and the thickness of the layer was up to ~150 μm. The refinement and dispersion of the Cr phase contributed to improving the interruption capability of the Cu-Cr contacts. Compared with the untreated samples, the arc duration and the withstanding voltage of the laser surface melting (LSM) treated contacts with refined microstructure increased to 21% and 33%, respectively. The results demonstrated that the LSM method was an effective approach to optimize the microstructure of Cu-Cr alloy, which made it a promising modification method for Cu-Cr vacuum contact applications. |
| first_indexed | 2024-12-23T11:14:50Z |
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| id | doaj.art-f811945d846a4a12969026e95e653dce |
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| issn | 2075-4701 |
| language | English |
| last_indexed | 2024-12-23T11:14:50Z |
| publishDate | 2019-05-01 |
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| spelling | doaj.art-f811945d846a4a12969026e95e653dce2022-12-21T17:49:15ZengMDPI AGMetals2075-47012019-05-019558510.3390/met9050585met9050585Grain Refinement of Hypereutectic Immiscible Cu-50Cr Alloy during Rapid Melting and Solidification Induced by High Power Density Laser BeamsLitian Zhang0Gang Yu1Chongxin Tian2Xiuli He3Shaoxia Li4Institute of Mechanics, Chinese Academy of Sciences, Beijing 100190, ChinaInstitute of Mechanics, Chinese Academy of Sciences, Beijing 100190, ChinaInstitute of Mechanics, Chinese Academy of Sciences, Beijing 100190, ChinaInstitute of Mechanics, Chinese Academy of Sciences, Beijing 100190, ChinaInstitute of Mechanics, Chinese Academy of Sciences, Beijing 100190, ChinaThe microstructure of hypereutectic immiscible Cu-50Cr alloy (wt%) was effectively refined and homogenized by a high power density Nd:YAG continuous laser beam (power density 10<sup>4</sup>−10<sup>5</sup> MW/m<sup>2</sup>). The average grain size of Cr was effectively refined from ~100 μm to ~1 μm, and some of the Cr particles even decreased to a few hundred nanometers. The high cooling rate (7.29 × 10<sup>6</sup> K/s) effectively inhibited the coarsening effect on Cr particles during liquid phase separation (LPS). The spherical Cr particles were preferably dispersed in the melt layer, and the thickness of the layer was up to ~150 μm. The refinement and dispersion of the Cr phase contributed to improving the interruption capability of the Cu-Cr contacts. Compared with the untreated samples, the arc duration and the withstanding voltage of the laser surface melting (LSM) treated contacts with refined microstructure increased to 21% and 33%, respectively. The results demonstrated that the LSM method was an effective approach to optimize the microstructure of Cu-Cr alloy, which made it a promising modification method for Cu-Cr vacuum contact applications.https://www.mdpi.com/2075-4701/9/5/585Cu-Cr immiscible alloylaser surface melting (LSM)liquid phase separation (LPS)grain refinementrapid solidificationinterruption capability |
| spellingShingle | Litian Zhang Gang Yu Chongxin Tian Xiuli He Shaoxia Li Grain Refinement of Hypereutectic Immiscible Cu-50Cr Alloy during Rapid Melting and Solidification Induced by High Power Density Laser Beams Metals Cu-Cr immiscible alloy laser surface melting (LSM) liquid phase separation (LPS) grain refinement rapid solidification interruption capability |
| title | Grain Refinement of Hypereutectic Immiscible Cu-50Cr Alloy during Rapid Melting and Solidification Induced by High Power Density Laser Beams |
| title_full | Grain Refinement of Hypereutectic Immiscible Cu-50Cr Alloy during Rapid Melting and Solidification Induced by High Power Density Laser Beams |
| title_fullStr | Grain Refinement of Hypereutectic Immiscible Cu-50Cr Alloy during Rapid Melting and Solidification Induced by High Power Density Laser Beams |
| title_full_unstemmed | Grain Refinement of Hypereutectic Immiscible Cu-50Cr Alloy during Rapid Melting and Solidification Induced by High Power Density Laser Beams |
| title_short | Grain Refinement of Hypereutectic Immiscible Cu-50Cr Alloy during Rapid Melting and Solidification Induced by High Power Density Laser Beams |
| title_sort | grain refinement of hypereutectic immiscible cu 50cr alloy during rapid melting and solidification induced by high power density laser beams |
| topic | Cu-Cr immiscible alloy laser surface melting (LSM) liquid phase separation (LPS) grain refinement rapid solidification interruption capability |
| url | https://www.mdpi.com/2075-4701/9/5/585 |
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