Microstructure evolution in undercooled Ag-50at. %Cu hypereutectic alloy
Ag–Cu alloys, as one type of typical eutectic solders, have been widely used in microelectronic packaging. The welding performance of Ag–Cu solders is closely associated with their microstructures. However, the microstructure evolution of Ag–Cu alloys during solidification is still poorly understood...
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| Format: | Article |
| Language: | English |
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Elsevier
2023-09-01
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| Series: | Journal of Materials Research and Technology |
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| Online Access: | http://www.sciencedirect.com/science/article/pii/S2238785423017751 |
| _version_ | 1797646748271771648 |
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| author | Shunmeng Zhang Kai Xiong Ruixia Yang Hua Dai Haijun Wu Junjie He Yingwu Wang Li Wu Yong Mao |
| author_facet | Shunmeng Zhang Kai Xiong Ruixia Yang Hua Dai Haijun Wu Junjie He Yingwu Wang Li Wu Yong Mao |
| author_sort | Shunmeng Zhang |
| collection | DOAJ |
| description | Ag–Cu alloys, as one type of typical eutectic solders, have been widely used in microelectronic packaging. The welding performance of Ag–Cu solders is closely associated with their microstructures. However, the microstructure evolution of Ag–Cu alloys during solidification is still poorly understood. In this work, a new melt fluxing technique was proposed to investigate the microstructure evolution of undercooled Ag-50at.%Cu hypereutectic alloy. The maximum undercooling of Ag-50at.%Cu alloy can reach up to 135 K. The obtained results show that the microstructures consist of primary dendrite and lamellar eutectic at low undercooling (ΔT – 10 K). With the increase of undercooling, dendrites undergo refining (ΔT < 65 K) and then disappear completely (ΔT = 78 K) and appear again (ΔT = 119 K). It is also discovered that cellular lamellar eutectics formed with ΔT within range of 65 K–78 K. Unexpectedly, irregular microstructures are observed when ΔT > 135 K. Theoretical calculation results indicate that the formation of irregular eutectic is associated with the dendritic fragmentation and eutectic coarsening under larger undercooling (ΔT = 135 K). These results not only elucidate the relationship between the solidification microstructure and undercooling of Ag-50at. %Cu hypereutectic alloys but also has positive significance for other hyper-eutectic systems. |
| first_indexed | 2024-03-11T15:07:13Z |
| format | Article |
| id | doaj.art-d881360dba464bcb9d02ebc76acd10cc |
| institution | Directory Open Access Journal |
| issn | 2238-7854 |
| language | English |
| last_indexed | 2024-03-11T15:07:13Z |
| publishDate | 2023-09-01 |
| publisher | Elsevier |
| record_format | Article |
| series | Journal of Materials Research and Technology |
| spelling | doaj.art-d881360dba464bcb9d02ebc76acd10cc2023-10-30T06:02:55ZengElsevierJournal of Materials Research and Technology2238-78542023-09-012615841595Microstructure evolution in undercooled Ag-50at. %Cu hypereutectic alloyShunmeng Zhang0Kai Xiong1Ruixia Yang2Hua Dai3Haijun Wu4Junjie He5Yingwu Wang6Li Wu7Yong Mao8Materials Genome Institute, National Center for International Research on Photoelectric and Energy Materials, School of Materials and Energy, Yunnan University, Kunming 650091, PR ChinaMaterials Genome Institute, National Center for International Research on Photoelectric and Energy Materials, School of Materials and Energy, Yunnan University, Kunming 650091, PR China; Corresponding author.School of Business and Information, Yunnan Land and Resource Vocational College, Kunming 650091, PR China; Corresponding author.Kunming Institute of Precious Metals, Yunnan Precious Metals Laboratory Co., Ltd, Kunming 650228, PR ChinaKunming Institute of Precious Metals, Yunnan Precious Metals Laboratory Co., Ltd, Kunming 650228, PR ChinaMaterials Genome Institute, National Center for International Research on Photoelectric and Energy Materials, School of Materials and Energy, Yunnan University, Kunming 650091, PR ChinaMaterials Genome Institute, National Center for International Research on Photoelectric and Energy Materials, School of Materials and Energy, Yunnan University, Kunming 650091, PR ChinaMaterials Genome Institute, National Center for International Research on Photoelectric and Energy Materials, School of Materials and Energy, Yunnan University, Kunming 650091, PR ChinaMaterials Genome Institute, National Center for International Research on Photoelectric and Energy Materials, School of Materials and Energy, Yunnan University, Kunming 650091, PR China; Corresponding author.Ag–Cu alloys, as one type of typical eutectic solders, have been widely used in microelectronic packaging. The welding performance of Ag–Cu solders is closely associated with their microstructures. However, the microstructure evolution of Ag–Cu alloys during solidification is still poorly understood. In this work, a new melt fluxing technique was proposed to investigate the microstructure evolution of undercooled Ag-50at.%Cu hypereutectic alloy. The maximum undercooling of Ag-50at.%Cu alloy can reach up to 135 K. The obtained results show that the microstructures consist of primary dendrite and lamellar eutectic at low undercooling (ΔT – 10 K). With the increase of undercooling, dendrites undergo refining (ΔT < 65 K) and then disappear completely (ΔT = 78 K) and appear again (ΔT = 119 K). It is also discovered that cellular lamellar eutectics formed with ΔT within range of 65 K–78 K. Unexpectedly, irregular microstructures are observed when ΔT > 135 K. Theoretical calculation results indicate that the formation of irregular eutectic is associated with the dendritic fragmentation and eutectic coarsening under larger undercooling (ΔT = 135 K). These results not only elucidate the relationship between the solidification microstructure and undercooling of Ag-50at. %Cu hypereutectic alloys but also has positive significance for other hyper-eutectic systems.http://www.sciencedirect.com/science/article/pii/S2238785423017751Dendritic growthEutectic growthIrregular microstructureAg–Cu alloy |
| spellingShingle | Shunmeng Zhang Kai Xiong Ruixia Yang Hua Dai Haijun Wu Junjie He Yingwu Wang Li Wu Yong Mao Microstructure evolution in undercooled Ag-50at. %Cu hypereutectic alloy Journal of Materials Research and Technology Dendritic growth Eutectic growth Irregular microstructure Ag–Cu alloy |
| title | Microstructure evolution in undercooled Ag-50at. %Cu hypereutectic alloy |
| title_full | Microstructure evolution in undercooled Ag-50at. %Cu hypereutectic alloy |
| title_fullStr | Microstructure evolution in undercooled Ag-50at. %Cu hypereutectic alloy |
| title_full_unstemmed | Microstructure evolution in undercooled Ag-50at. %Cu hypereutectic alloy |
| title_short | Microstructure evolution in undercooled Ag-50at. %Cu hypereutectic alloy |
| title_sort | microstructure evolution in undercooled ag 50at cu hypereutectic alloy |
| topic | Dendritic growth Eutectic growth Irregular microstructure Ag–Cu alloy |
| url | http://www.sciencedirect.com/science/article/pii/S2238785423017751 |
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