|
|
SELECTION OF THE SOLIDIFICATION PATH OF Mg-Zn-Gd TERNARY CASTING ALLOY |
Shaojun LIU,Guangyu YANG(),Wanqi JIE |
State Key Laboratory of Solidification Processing, Northwestern Polytechnical University, Xi'an 710072 |
|
Cite this article:
Shaojun LIU, Guangyu YANG, Wanqi JIE. SELECTION OF THE SOLIDIFICATION PATH OF Mg-Zn-Gd TERNARY CASTING ALLOY. Acta Metall Sin, 2015, 51(5): 580-586.
|
Abstract Mg-Zn-Gd base alloys possess much superiority, such as, high strength, light weight, low cost, etc., and favorable for the application in various airframe components. Two kinds of eutectic phases, such as, W(Mg3Zn3Gd2) and I(Mg3Zn6Gd), can be usually found in Mg-Zn-Gd alloy under the traditional casting conditions. The interface between W phase and α(Mg) is incoherent and thus weak. However, I phase has quasiperiodic lattice leading to a coherent interface between I phase and α(Mg). Therefore, compared with W phase, I phase is more effective to obstruct dislocations slipping and so efficiently strengthening the alloy. So, controlling the solidification path, i.e., controlling the relative amount of I phase and W phase, is critical for increasing the heat resistant of Mg-Zn-Gd magnesium alloy. In this work, the solidification path of Mg-4.58Zn-2.6Gd ternary casting alloy was investigated by experiments and numerical analysis. Experimental results showed that at lower cooling rate (≤0.75 K/s), α+W(Mg3Zn3Gd2) eutectic will be formed first, while at higher cooling rate (≥7.71 K/s), α(Mg)+I(Mg3Zn6Gd) eutectic will be formed first. A numerical model for predicting solidification path of the primary phase in multi-component alloy with considering the effects of solute diffusion in liquid phase and the cooling rate was developed. The thermodynamic data in the computation model was obtained by using the database of Thermo-Calc. The numerical results were in favorable agreement with the experimental ones. The numerical model established in this work provides a direct and easy way to predict solidification path of Mg-Zn-Gd alloy for different casting conditions. The validity of this model was further confirmed by other three different Mg-Zn-Gd alloys, i.e., Mg-3.8Zn-2.0Gd, Mg-5.5Zn-2.0Gd and Mg-5.5Zn-4Gd. It is also found that for Mg-Zn-Gd alloy, the higher Zn-content and the higher cooling rate will promote the formation of I phase. However, higher Gd-content and the lower cooling rate is favorable for the formation of W phase.
|
Received: 15 September 2014
|
Fund: National Natural Science Foundation of China (Nos.51071129 and 51227001) |
[1] | Yang Z, Li J P, Zhang J X, Lorimer G W, Robson J. Acta Metall Sin (Engl Lett), 2008; 21: 313 | [2] | Huang H, Chen C L, Wang Z C, Li Y P, Yuan G Y. Mater Sci Eng, 2013; A581: 73 | [3] | Liu Y, Yuan G, Ding W, Lu C. J Alloys Compd, 2007; 427: 160 | [4] | Yang J, Wang L D, Wang L M, Zhang H J. J Alloys Compd, 2008; 459: 274 | [5] | Liu Y, Yuan G Y, Lu C, Ding W J. Scr Mater, 2006; 55: 919 | [6] | Liu Y, Shao S, Xu C S, Zeng X S, Yang X J. Mater Sci Eng, 2013; A588: 76 | [7] | Liu Y, Yuan G Y, Zhang S, Zhang X P, Ding W J. Mater Trans, 2008; 49: 941 | [8] | Jie W Q, Zhang R J, He Z. Mater Sci Eng, 2005; A413: 497 | [9] | Zhao G W, Li X Z, Xu D M, Fu H Z, Du Y, He Y H. Acta Metall Sin, 2011; 47: 1135 (赵光伟, 李新中, 徐达鸣, 傅恒志, 杜 勇, 贺跃辉. 金属学报, 2011; 47: 1135) | [10] | Jie W Q,Jian Z Y,Liu L,Yang G Y,Li S M,Shen J,Wang H M. Casting Technology. Beijing: Higher Education Press, 2013: 4 (介万奇,坚增运,刘 林,杨光昱,李双明,沈 军,王华明. 铸造技术. 北京: 高等教育出版社, 2013: 4 ) | [11] | Wu M, Li J, Ludwig A, Kharcha A. Comp Mater Sci, 2013; 79: 830 | [12] | Mehrabian R, Flemings M C. Metall Trans, 1970; 1A: 455 | [13] | Clyne T W, Kurz W. Metall Trans, 1981; 12A: 965 | [14] | Ohnaka I. Trans ISIJ, 1986; 26: 1045 | [15] | Kobayashi S. Trans ISIJ, 1988; 28: 728 | [16] | Liu S J, Yang G Y, Zhang S L, Jie W Q. Spec Casting Nonferrous Alloys, 2011; 31: 278 (刘少军, 杨光昱, 张胜利, 介万奇. 特种铸造及有色合金, 2011; 31: 278) | [17] | Sundman B, Jansson B, Andersson J O. Calphad, 1985; 9: 153 | [18] | Dupont J N, Robino C V, Marder A R. Acta Mater, 1998; 46: 4781 | [19] | Rappaz M, Boettinger W J. Acta Mater, 1999; 47: 3205 | [20] | Zhou J X, Yang Y S, Tong W H, Wang J, Fu J W, Wang B. Rare Met Mater Eng, 2010; 39: 1899 | [21] | Andersson J O, Thomas H, Sundman B. Calphad, 2002; 26: 273 | [22] | Hillert M. J Alloys Compd, 2001; 320: 161 | [23] | Qi H Y, Huang G X, Bo H, Xu G L, Liu L B, Jin Z P. J Mater Sci, 2012; 47: 1319 | [24] | Furer U, Wunderlin R. Metal Solidification. Stuttgart: DGM Fachber, 1977: 1 | [25] | Zhang R J. PhD Dissertation, Northwestern Polytechnical University, Xi'an, 2004 (张瑞杰. 西北工业大学博士学位论文, 西安, 2004) |
|
No Suggested Reading articles found! |
|
|
Viewed |
|
|
|
Full text
|
|
|
|
|
Abstract
|
|
|
|
|
Cited |
|
|
|
|
|
Shared |
|
|
|
|
|
Discussed |
|
|
|
|