Please wait a minute...
金属学报  2015, Vol. 51 Issue (6): 677-684    DOI: 10.11900/0412.1961.2014.00501
  论文 本期目录 | 过刊浏览 |
铝合金凝固过程枝晶破碎现象的定量化研究*
毕成1,郭志鹏1(),LIOTTI E2,熊守美1,GRANT P S2
1 清华大学材料学院, 北京100084
2 Department of Materials, University of Oxford, Oxford OX1 3PH, UK
QUANTIFICATION STUDY ON DENDRITE FRAGMENTATION IN SOLIDIFICATION PROCESS OF ALLUMINUM ALLOYS
Cheng BI1,Zhipeng GUO1(),E LIOTTI2,Shoumei XIONG1,P S GRANT2
1 School of Materials Science and Engineering, Tsinghua University, Beijing 100084
2 Department of Materials, University of Oxford, Oxford OX1 3PH, UK
引用本文:

毕成, 郭志鹏, LIOTTI E, 熊守美, GRANT P S. 铝合金凝固过程枝晶破碎现象的定量化研究*[J]. 金属学报, 2015, 51(6): 677-684.
Cheng BI, Zhipeng GUO, E LIOTTI, Shoumei XIONG, P S GRANT. QUANTIFICATION STUDY ON DENDRITE FRAGMENTATION IN SOLIDIFICATION PROCESS OF ALLUMINUM ALLOYS[J]. Acta Metall Sin, 2015, 51(6): 677-684.

全文: PDF(4038 KB)   HTML
摘要: 

利用X射线同步辐射影像技术对Al-15%Cu (质量分数)合金凝固过程的枝晶生长和破碎现象进行了实时观察. 通过加入脉冲电磁场和改变枝晶生长方向获得了大量不同实验条件下的动态影像. 利用Matlab软件对实验结果进行定量化分析, 开发了统计测量程序, 统计了枝晶破碎数量随不同实验条件的变化, 测量了枝晶破碎数量沿糊状区深度、糊状区固相率的分布关系. 结果表明, 加入电磁场、逆重力方向生长和生长速度快的枝晶会产生更多的枝晶破碎; 枝晶破碎数量沿着糊状区深度、糊状区固相率呈一定的Gauss分布, 且在固相率为0.45左右达到峰值. 最后分析了速度场造成的缩颈断裂、重力场造成的溶质富积以及电磁场造成的晶间对流对上述定量化结果的影响程度.

关键词 铝合金X射线同步辐射凝固枝晶破碎糊状区电磁场    
Abstract

Alloy solidification is an important process to control the mechanical properties of engineering products. During solidification, dendrite fragmentation occurs commonly as a key phenomenon to determine the microstructure and to obtain fine grain size. Recently, in situ synchrotron X-radiography technique was developed and applied to observe thermodynamic behaviors such as dendrite growth and fragmentation during solidification. External forces such as mechanical and electromagnetic stirring, and thermal shock were added into the solidification process to investigate their effects on the fragmentation behavior. However, most work conducted in literature focused on qualitative aspects e.g. morphology transition or solute distribution and quantitative investigation such as determining the specific relationship between fragmentation and solidification conditions was rather limited. In this work, the third generation synchrotron X-radiography technique was used to observe the solidification process of an Al-15%Cu (mass fraction) alloy. Experimental conditions including the strength of the pulsed electromagnetic fields, dendrite growth direction and the temperature gradients were varied and the subsequent effect on fragmentation was studied and quantified. A computer program was developed based on Matlab to perform the image processing and measurement. The fragmentation number according to experiments was counted and correlated to the mushy zone depth and local solid fraction. Results showed that a stronger electromagnetic field, growing against gravity and growing at higher velocity would significantly increase the fragmentation number. Furthermore, the fragmentation number followed a Gauss distribution as a function of either mushy zone depth or local solid fraction, and the maximum fragmentation occurred when the solid fraction was about 0.45. In the end, the extent to which caused those statistic results above were analyzed as the necking process due to the velocity field, the cumulative solid due to the gravity field and the liquid flow due to the electromagnetic field.

Key wordsaluminum alloy    X-ray synchrotron radiation    solidification    dendrite fragmentation    mushy zone    electromagnetic field
    
基金资助:*国家自然科学基金项目51275269和51205229资助
图1  同步辐射实验平台构建示意图
Group No. Growth direction Lorentz force / mN Number of replication
A Bottom to top - 16
B 0.3 10
C Top to bottom - 10
D 0.3 5
E 0.9 7
表1  实验条件分组
图2  糊状区固相率测量
图3  破碎枝晶所处糊状区的深度及枝晶生长速度测量示意图
图4  不同实验条件下枝晶破碎数随时间累积变化及线性拟合
图5  枝晶破碎随糊状区深度的分布直方图
Group No. Expected value / μm Standard deviation / mm R2
A 587 530 0.9818
B 504 588 0.9836
C 619 414 0.9715
D(E) 483(1005) 279(298) 0.9786
表2  枝晶破碎的Gauss分布拟合结果
图6  枝晶破碎随糊状区固相率的分布直方图
图7  枝晶主干断裂数与枝晶主干生长速度对比
No. Approximate slope of curves in Fig.7a Average tip velocity in Fig.7b / (mms-1)
1 0.1954 15.3167
2 0.1079 8.9249
3 0.0534 7.9262
4 0.0342 6.3794
5 0.1153 12.1784
表3  生长速度与主干断裂的关系
[1] Jie W Q, Zhou Y H. J Northwest Polytech Univ, 1988; 6(1): 29 (介万奇, 周尧和. 西北工业大学学报, 1988; 6(1): 29)
[2] Grange G, Gastaldi J, Jourdan C, Billia B. J Cryst Growth, 1995; 151: 192
[3] Mathiesen R H, Arnberg L, Ramsoskar K, Weitkamp T, Rau C, Snigirev A. Metall Mater Trans, 2002; 33B: 613
[4] Mathiesen R H, Arnberg L. Mater Sci Eng, 2005; A413: 283
[5] Mathiesen R H, Arnberg L, Bleuet P, Somogyi A. Metall Mater Trans, 2006; 37A: 2515
[6] Limodin N, Salvo L, Suery M, DiMichiel M. Acta Mater, 2007; 55: 3177
[7] Campanella T, Charbon C, Rappaz M. Metall Mater Trans, 2004; 35A: 3201
[8] Li M J, Tamura T, Omura N, Miwa K. J Alloys Compd, 2010; 494: 116
[9] Wang T M, Zhu J, Chen Z N, Xu J J. Sci Sin Phy, Mech Astron, 2011; 41: 23 (王同敏, 朱 晶, 陈宗宁, 许菁菁. 中国科学: 物理学 力学 天文学, 2011; 41: 23)
[10] Liotti E, Liu A, Vincent R, Kumar S, Guo Z, Connolley T, Dolbnya I P, Hart M, Arnberg L, Mathiesen R H, Grant P S. Acta Mater, 2014; 70: 228
[11] Shu D, Sun B D, Mi J W, Grant P S. Phys Metall Mater Sci, 2012; 43A: 3755
[12] Mapelli C, Gruttadauria A, Peroni M. J Mater Process Technol, 2010; 210: 306
[13] Ruvalcaba D, Mathiesen R H, Eskin D G, Arnberg L, Katgerman L. Acta Mater, 2007; 55: 4287
[14] Pataric A, Mihailovic M, Gulisija Z. J Mater Sci, 2012; 47: 793
[15] Liu S, Lu S Z, Hellawell A. J Cryst Growth, 2002; 234: 740
[16] Yasuda H, Ohnaka I, Kawasaki K, Suglyama A, Ohmichi T, Iwane J, Umetani K. J Cryst Growth, 2004; 262: 645
[17] Stransky K, Kavicka F, Sekanina B, Stetina J, Gontarev V, Dobrovska J. Mater Technol, 2011; 45: 163
[18] Arnberg L, Mathiesen R H. JOM, 2007; 59(8): 20
[19] Ananiev S, Nikrityuk P, Eckert K. Acta Mater, 2009; 57: 657
[20] Schenk T, Thi H N, Gastaldi J, Reinhart G, Cristiglio V, Mangelinck-Noel N, Klein H, Hartwig J, Grushko B, Billia B. J Cryst Growth, 2005; 275: 201
[21] Zhu J, Wang T M, Chen Z N, Xu J J, Xie H L, Xiao T Q, Li T J. In: Ludwig A ed., IOP Conf Ser: Mater Sci Eng, 2012; 33: paper No.012039
[22] Guo Z, Mi J, Xiong S M, Grant P S. J Comput Phys, 2014; 257: 278
[23] Rack A, Weitkamp T, Riotte M, Grigoriev D, Rack T, Helfen L, Baumbach T, Dietsch R, Holz T, Kramer M, Siewert F, Meduna M, Cloetens P, Ziegler E. J Synchrotron Radiat, 2010; 17: 496
[24] Puncreobutr C, Phillion A B, Fife J L, Lee P D. Acta Mater, 2014; 64: 316
[25] Nielsen O, Arnberg L, Mo A, Thevik H. Metall Mater Trans, 1999; 30A: 2455
[1] 马德新, 赵运兴, 徐维台, 王富. 重力对高温合金定向凝固组织的影响[J]. 金属学报, 2023, 59(9): 1279-1290.
[2] 张健, 王莉, 谢光, 王栋, 申健, 卢玉章, 黄亚奇, 李亚微. 镍基单晶高温合金的研发进展[J]. 金属学报, 2023, 59(9): 1109-1124.
[3] 王宗谱, 王卫国, Rohrer Gregory S, 陈松, 洪丽华, 林燕, 冯小铮, 任帅, 周邦新. 不同温度轧制Al-Zn-Mg-Cu合金再结晶后的{111}/{111}近奇异晶界[J]. 金属学报, 2023, 59(7): 947-960.
[4] 刘继浩, 周健, 武会宾, 马党参, 徐辉霞, 马志俊. 喷射成形M3高速钢偏析成因及凝固机理[J]. 金属学报, 2023, 59(5): 599-610.
[5] 侯娟, 代斌斌, 闵师领, 刘慧, 蒋梦蕾, 杨帆. 尺寸设计对选区激光熔化304L不锈钢显微组织与性能的影响[J]. 金属学报, 2023, 59(5): 623-635.
[6] 夏大海, 计元元, 毛英畅, 邓成满, 祝钰, 胡文彬. 2024铝合金在模拟动态海水/大气界面环境中的局部腐蚀机制[J]. 金属学报, 2023, 59(2): 297-308.
[7] 苏震奇, 张丛江, 袁笑坦, 胡兴金, 芦可可, 任维丽, 丁彪, 郑天祥, 沈喆, 钟云波, 王晖, 王秋良. 纵向静磁场下单晶高温合金定向凝固籽晶回熔界面杂晶的形成与演化[J]. 金属学报, 2023, 59(12): 1568-1580.
[8] 高建宝, 李志诚, 刘佳, 张金良, 宋波, 张利军. 计算辅助高性能增材制造铝合金开发的研究现状与展望[J]. 金属学报, 2023, 59(1): 87-105.
[9] 梁琛, 王小娟, 王海鹏. 快速凝固Ti-Al-Nb合金B2相形成机制与显微力学性能[J]. 金属学报, 2022, 58(9): 1169-1178.
[10] 马志民, 邓运来, 刘佳, 刘胜胆, 刘洪雷. 淬火速率对7136铝合金应力腐蚀开裂敏感性的影响[J]. 金属学报, 2022, 58(9): 1118-1128.
[11] 刘仁慈, 王鹏, 曹如心, 倪明杰, 刘冬, 崔玉友, 杨锐. 700℃热暴露对 β 凝固 γ-TiAl合金表面组织及形貌的影响[J]. 金属学报, 2022, 58(8): 1003-1012.
[12] 李彦强, 赵九洲, 江鸿翔, 何杰. Pb-Al合金定向凝固组织形成过程[J]. 金属学报, 2022, 58(8): 1072-1082.
[13] 李闪闪, 陈云, 巩桐兆, 陈星秋, 傅排先, 李殿中. 冷速对高碳铬轴承钢液析碳化物凝固析出机制的影响[J]. 金属学报, 2022, 58(8): 1024-1034.
[14] 宋文硕, 宋竹满, 罗雪梅, 张广平, 张滨. 粗糙表面高强铝合金导线疲劳寿命预测[J]. 金属学报, 2022, 58(8): 1035-1043.
[15] 王春辉, 杨光昱, 阿热达克·阿力玛斯, 李晓刚, 介万奇. 砂型3DP打印参数对ZL205A合金铸造性能的影响[J]. 金属学报, 2022, 58(7): 921-931.