| 题名: | Effect of Holding Time on Surface Films Formed on Molten AZ91D Alloy Protected by Graphite Powder |
| 作者: | Li, Weihong; Zhou, Jixue; Ma, Baichang; Wang, Jinwei; Wu, Jianhua; Yang, Yuansheng |
| 发表日期: | 2017-10-1 |
| 摘要: | Graphite powder was adopted to prevent the AZ91D magnesium alloy from oxidizing during the melting and casting process. The microstructure of the resultant surface films formed at 973 K (700 A degrees C) holding for 0, 15, 30, 45, and 60 minutes was investigated by scanning electron microscopy, energy dispersive spectroscopy (EDS), and X-ray diffraction (XRD) after mechanical polishing and chemical etching. The results indicated that the surface films were composed of a protective layer and the underneath particles with different morphology. The protective layer was continuous with a thickness of 200 to 1000 nm mainly consisting of MgO, MgF2, and C, while the underneath particles mainly consisted of MgF2 and MgAl2O4. The surface films were the result of the interaction between the graphite powder, the melt, and the ambient atmosphere. The number and the size of the underneath particles, determining the thickness uniformity of the surface films, and the unevenness of the microsurface morphology increased with holding time. The mechanism of holding time on the resultant surface films was also discussed. |
| 刊名: | SPRINGER |
| Appears in Collections: | 中国科学院金属研究所_期刊论文
|
Files in This Item:
There are no files associated with this item.
|
| Recommended Citation: | |
Li, Weihong,Zhou, Jixue,Ma, Baichang,et al. Effect Of Holding Time On Surface Films Formed On Molten Az91d Alloy Protected By Graphite Powder[J]. Springer,2017,48(5):2334-2342.
|
|
|
