Effects of melt convection on stray grain formation in single crystal superalloys during directed energy deposition
文献类型：期刊论文
| 作者 | Lu, Nannan2,3; Lei, Zhenglong3; Yu, Xingfu1; Bi, Jiang3; Chen, Yanbin3 |
| 刊名 | ADDITIVE MANUFACTURING
 |
| 出版日期 | 2021-12-01 |
| 卷号 | 48页码:19 |
| ISSN号 | 2214-8604 |
| 关键词 | Directed energy deposition Ni-based superalloy Stray grain Marangoni convection Melt pool geometry |
| DOI | 10.1016/j.addma.2021.102429 |
| 通讯作者 | Lei, Zhenglong(leizhenglong@hit.edu.cn) |
| 英文摘要 | During laser repairing of Ni-based single crystal (SX) superalloys, stray grain (SGs) formation leads to a deterioration of high-temperature properties and hot cracking. The main goal is to prevent SGs formation from forming, which controls the local solidification front thermal gradient (G) and solidification velocity (V). Meanwhile, the melt pool geometry, which is influenced by melt convection, has a significant impact on G and V. Here, experiments and theoretical calculations were used to study the evolution of the melt pool geometry during melt convection and its effects on the formation of SGs. Melt convection, i.e., Marangoni convection, outperformed thermal conduction in the SX superalloys melt pool during directed energy deposition, as evidenced by the estimated Peclet number and Prandtl number. The integrative impact of laser power, scan velocity, and beam diameters exacerbated Marangoni convection as the laser energy density distribution increased. Marangoni convection caused the melt pool shape to change from a near-semicircle to an undulating morphology, promoting the oriented-to-misoriented crystal growth transition and resulting in high stray grain sensitivity. The heat and mass transport in front of the dendrite tips was altered by Marangoni convection, which aggravated the deviation of the epitaxial dendrite orientation with respect to the substrate. This work provides an in-depth insight into controlling SG formation during additive manufacturing of SX superalloys. |
| WOS研究方向 | Engineering ; Materials Science |
| 语种 | 英语 |
| 出版者 | ELSEVIER |
| WOS记录号 | WOS:000720745300002 |
| 源URL | [http://ir.imr.ac.cn/handle/321006/167417]  |
| 专题 | 金属研究所_中国科学院金属研究所 |
| 通讯作者 | Lei, Zhenglong |
| 作者单位 | 1.Shenyang Univ Technol, Sch Mat Sci & Engn, Shenyang 110178, Peoples R China 2.Chinese Acad Sci, Inst Met Res, Shenyang 110016, Peoples R China 3.Harbin Inst Technol, State Key Lab Adv Welding & Joining, Harbin 150001, Peoples R China |
| 推荐引用方式 GB/T 7714 | Lu, Nannan,Lei, Zhenglong,Yu, Xingfu,et al. Effects of melt convection on stray grain formation in single crystal superalloys during directed energy deposition[J]. ADDITIVE MANUFACTURING,2021,48:19. |
| APA | Lu, Nannan,Lei, Zhenglong,Yu, Xingfu,Bi, Jiang,&Chen, Yanbin.(2021).Effects of melt convection on stray grain formation in single crystal superalloys during directed energy deposition.ADDITIVE MANUFACTURING,48,19. |
| MLA | Lu, Nannan,et al."Effects of melt convection on stray grain formation in single crystal superalloys during directed energy deposition".ADDITIVE MANUFACTURING 48(2021):19. |
入库方式： OAI收割
来源：金属研究所
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