Modeling studies on divorced eutectic formation of high pressure die cast magnesium alloy
The morphology and content of the divorced eutectic in the microstructure of high pressure die casting (HPDC) magnesium alloy have a great influence on the final performance of castings. Based on the previous work concerning simulation of the nucleation and dendritic growth of primary α-Mg during th...
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| Format: | Article |
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Foundry Journal Agency
2018-01-01
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| Series: | China Foundry |
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| Online Access: | http://ff.foundryworld.com/uploadfile/2018020629086357.pdf |
| _version_ | 1819264875418877952 |
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| author | Meng-wu Wu *Lin Hua Shou-mei Xiong |
| author_facet | Meng-wu Wu *Lin Hua Shou-mei Xiong |
| author_sort | Meng-wu Wu |
| collection | DOAJ |
| description | The morphology and content of the divorced eutectic in the microstructure of high pressure die casting (HPDC) magnesium alloy have a great influence on the final performance of castings. Based on the previous work concerning simulation of the nucleation and dendritic growth of primary α-Mg during the solidification of magnesium alloy under HPDC process, an extension was made to the formerly established CA (Cellular Automaton) model with the purpose of modeling the nucleation and growth of Mg-Al eutectic. With a temperature field and solute field obtained during simulation of the primary α-Mg dendrites as the initial condition of the modified CA model, modeling of the Mg-Al eutectic with a divorced morphology was achieved. Moreover, the simulated results were in accordance with the experimental ones regarding the distribution and content of the divorced eutectic. Taking a "cover-plate" die casting with AM60 magnesium alloy as an example, the rapid solidification with a high cooling rate at the surface layer of the casting led to a fine and uniform grain size of primary α-Mg, while the divorced eutectic at the grain boundary revealed a more dispersed and granular morphology. Islands of divorced eutectic were observed at the central region of the casting, due to the existence of ESCs (Externally Solidified Crystals) which contributed to a coarse and non-uniform grain size of primary α-Mg. The volume percentage of the eutectic β-Mg17Al12 phase is about 2%-6% in the die casting as a whole. The numerical model established in this study is of great significance to the study of the divorced eutectic in the microstructure of die cast magnesium alloy. |
| first_indexed | 2024-12-23T20:36:26Z |
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| id | doaj.art-ba4ae14e983e44948388c164c60998b7 |
| institution | Directory Open Access Journal |
| issn | 1672-6421 1672-6421 |
| language | English |
| last_indexed | 2024-12-23T20:36:26Z |
| publishDate | 2018-01-01 |
| publisher | Foundry Journal Agency |
| record_format | Article |
| series | China Foundry |
| spelling | doaj.art-ba4ae14e983e44948388c164c60998b72022-12-21T17:32:03ZengFoundry Journal AgencyChina Foundry1672-64211672-64212018-01-01151586510.1007/s41230-018-7207-2Modeling studies on divorced eutectic formation of high pressure die cast magnesium alloyMeng-wu Wu0*Lin Hua1Shou-mei Xiong21. Hubei Key Laboratory of Advanced Technology for Automotive Components, Wuhan University of Technology, Wuhan 430070, China; 2. Hubei Collaborative Innovation Center for Automotive Components Technology, Wuhan 430070, China;1. Hubei Key Laboratory of Advanced Technology for Automotive Components, Wuhan University of Technology, Wuhan 430070, China; 2. Hubei Collaborative Innovation Center for Automotive Components Technology, Wuhan 430070, China;3. School of Materials Science and Engineering, Tsinghua University, Beijing 100084, ChinaThe morphology and content of the divorced eutectic in the microstructure of high pressure die casting (HPDC) magnesium alloy have a great influence on the final performance of castings. Based on the previous work concerning simulation of the nucleation and dendritic growth of primary α-Mg during the solidification of magnesium alloy under HPDC process, an extension was made to the formerly established CA (Cellular Automaton) model with the purpose of modeling the nucleation and growth of Mg-Al eutectic. With a temperature field and solute field obtained during simulation of the primary α-Mg dendrites as the initial condition of the modified CA model, modeling of the Mg-Al eutectic with a divorced morphology was achieved. Moreover, the simulated results were in accordance with the experimental ones regarding the distribution and content of the divorced eutectic. Taking a "cover-plate" die casting with AM60 magnesium alloy as an example, the rapid solidification with a high cooling rate at the surface layer of the casting led to a fine and uniform grain size of primary α-Mg, while the divorced eutectic at the grain boundary revealed a more dispersed and granular morphology. Islands of divorced eutectic were observed at the central region of the casting, due to the existence of ESCs (Externally Solidified Crystals) which contributed to a coarse and non-uniform grain size of primary α-Mg. The volume percentage of the eutectic β-Mg17Al12 phase is about 2%-6% in the die casting as a whole. The numerical model established in this study is of great significance to the study of the divorced eutectic in the microstructure of die cast magnesium alloy.http://ff.foundryworld.com/uploadfile/2018020629086357.pdfmagnesium alloyhigh pressure die castingmicrostructure simulationdivorced eutectic |
| spellingShingle | Meng-wu Wu *Lin Hua Shou-mei Xiong Modeling studies on divorced eutectic formation of high pressure die cast magnesium alloy China Foundry magnesium alloy high pressure die casting microstructure simulation divorced eutectic |
| title | Modeling studies on divorced eutectic formation of high pressure die cast magnesium alloy |
| title_full | Modeling studies on divorced eutectic formation of high pressure die cast magnesium alloy |
| title_fullStr | Modeling studies on divorced eutectic formation of high pressure die cast magnesium alloy |
| title_full_unstemmed | Modeling studies on divorced eutectic formation of high pressure die cast magnesium alloy |
| title_short | Modeling studies on divorced eutectic formation of high pressure die cast magnesium alloy |
| title_sort | modeling studies on divorced eutectic formation of high pressure die cast magnesium alloy |
| topic | magnesium alloy high pressure die casting microstructure simulation divorced eutectic |
| url | http://ff.foundryworld.com/uploadfile/2018020629086357.pdf |
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