Modification of Mg2Si in Mg–Si alloys with gadolinium
| Autor: | Zhaoyang Liu, Xinming Zhang, Jilong Hu, Zhile Zhou, Yunlai Deng, Lingying Ye, Tang Changping |
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| Rok vydání: | 2013 |
| Předmět: |
Materials science
Scanning electron microscope Mechanical Engineering Gadolinium Alloy Analytical chemistry chemistry.chemical_element engineering.material Condensed Matter Physics law.invention Dendrite (crystal) Crystallography chemistry Optical microscope Mechanics of Materials law X-ray crystallography engineering General Materials Science Electron microscope Eutectic system |
| Zdroj: | Materials Characterization. 79:1-6 |
| ISSN: | 1044-5803 |
| DOI: | 10.1016/j.matchar.2013.02.005 |
| Popis: | The modification effect of gadolinium (Gd) on Mg 2 Si in the hypereutectic Mg–3 wt.% Si alloy has been investigated using optical microscope, scanning electron microscope, X-ray diffraction and hardness measurements. The results indicate that the morphology of the primary Mg 2 Si is changed from coarse dendrite into fine polygon with the increasing Gd content. The average size of the primary Mg 2 Si significantly decreases with increasing Gd content up to 1.0 wt.%, and then slowly increases. Interestingly, when the Gd content is increased to 4.0 and 8.0 wt.%, the primary and eutectic Mg 2 Si evidently decrease and even disappear. The modification and refinement of the primary Mg 2 Si is mainly attributed to the poisoning effect. The GdMg 2 phase in the primary Mg 2 Si is obviously coarsened as the Gd content exceeds 2.0 wt.%. While the decrease and disappearance of the primary and eutectic Mg 2 Si are ascribed to the formation of vast GdSi compound. Therefore, it is reasonable to conclude that proper Gd (1.0 wt.%) addition can effectively modify and refine the primary Mg 2 Si. |
| Databáze: | OpenAIRE |
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