STATISTICAL STUDY OF THE PRIMARY-DENDRITE SPACINGS IN SINGLE-CRYSTAL SUPERALLOYS

Xiaoli Zhang; Tingzhen Xin; Shuaishuai Yue; Xiangbin Meng; Guiqun Liu

Xiaoli Zhang School of Material Science and Engineering, North Minzu University, Yinchuan 750021, China
Tingzhen Xin School of Material Science and Engineering, North Minzu University, Yinchuan 750021, China
Shuaishuai Yue School of Material Science and Engineering, North Minzu University, Yinchuan 750021, China
Xiangbin Meng School of Mechanical and Automotive Engineering, Qilu University of Technology , Shandong Academy of Sciences, Jinan 250353, China
Guiqun Liu School of Material Science and Engineering, North Minzu University, Yinchuan 750021, China

Keywords: directional solidification, seeding, single-crystal superalloy, primary-dendrite spacing

Abstract

Three generations of single-crystal superalloys (AM3, DD5 and DD90) were produced with directional solidification and seeding. The square-calculation method and direct-measurement method were used to study the primary-dendrite spacings of the three single-crystal superalloys at different solidification distances (50, 150 and 250) mm. Statistical results showed that, firstly, as the solidification heights increased, the average primary-dendrite spacings of the three alloys were gradually enlarged; secondly, the average primary-dendrite spacings calculated with the square-calculation method and the direct-measurement method were similar, which indicated the high precision of the two methods; thirdly, the primary-dendrite spacings of the three alloys were distributed randomly in a relatively large range, following a normal distribution. The maximum values of the primary-dendrite spacings were 4.7–8.5 times larger than the minimum ones at different solidification distances and were different from the values from previous studies.

References

1 W. Kurz, D. J. Fisher, Fundamentals of solidification, 3rd edition, Trans Tech Publications, Aedermannsdorf, 1992
2 G. Hu, X. Cai, Y. Rong, Fundamentals of Materials Science, 3rd edition, Shanghai Jiaotong University Press, Shanghai, China 2014, 243
3 M. C. Flemings, Solidification processing, McGraw-Hill, Inc., New York 1974
4 R. C. Reed, The Superalloys: Fundamentals and Applications, Cambridge University Press, UK 2006, 141
5 R. E. Schafrik, S. Walston, Challenges for high temperature materials in the new millennium, Superalloys 2008, TMS, Warrendale, PA, USA 2008, 3–9
6 M. McLean, Directionally solidified materials for high temperature service, The Metals Society, London 1983, 161
7 R. E. Shalin, I. L. Svetlov, E. B. Kachanov, V. N. Toloraiia, O. S. Gavrilin, Single Crystals of Nickel Superalloys, Mocshinostroeniye, Moscow 1997, 336
8 K. P. L. Fullagar, R. W. Broom?eld, M. Hulands, K. Harris, G. L. Erickson, S. L. Sikkenga, Aero engine test experience with CMSX-4 alloy single-crystal turbine blades, J. Eng. Gas Turbines Power, 118 (1996), 380–388
9 M. J. Goulette, P. D. Spilling, R. P. Arthey, Cost effective single crystals, Superalloys 1984, TMS Warrendale, PA, USA 1984, 167–176
10 J. D. Hunt, Solidification and casting of metals, The Metal Society, London 1979, 3-12
11 W. Kurz, D. J. Fisher, Dendrite growth at the limit of stability: tip radius and spacing, Acta Metal., 29 (1981) 1, 11-20
12 R. Trivedi, Interdendritic spacing: Part II. A comparison of theory and experiment, Metall. Trans. A, 15 (1984), 977-982
13 J. D. Hunt, S. Z. Lu, Numerical modeling of cellular/dendritic array growth: Spacing and structure predictions, Metall. Mater. Trans. A, 27 (1996), 611-623
14 A. Warrenjames, J. S. Langer, Prediction of dendritic spacing in a directional-solidification experiment, Physics Review E, 47 (1993) 4, 2702-2712
15 O. L. Rocha, C. A. Siqueira, A. Garcia, Heat Flow Parameters Affecting Dendrite Spacings during Unsteady-State Solidification of Sn-Pb and Al-Cu Alloys, Metall. Mater. Trans. A, 34 (2003), 995–1006
16 M. Gunduz, E. Cadirli, Directional Solidification of Aluminium-Copper Alloys, Mater. Sci. Eng. A, 327 (2002), 167–185
17 Huang Weidong, Geng Xingguo, Zhou Yaohe. Primary spacing selection of constrained dendritic growth, Journal of Crystal Growth, 134 (1993), 105–115
18 G. L. Ding, W. D. Huang, X. Huang, X. Lin, Y. H. Zhou, On primary dendritic spacing during unindirectional solidification, Acta Metallurgica et Materialia, 44 (1996) 9, 3705–3709
19 S. H. Han, R. Trivedi, Primary spacing selection in directionally solidification alloys, Acta Metallurgica et Materialia, 42 (1994) 1, 25–41
20 L. X. Li, X. Lin, M. Wang, W. D. Huang, Selection of Primary Dendritic Spacing during Directional Solidification of Al-3.6% Cu, Foundry Technology, 29 (2008), 891–895
21 S.-Z. Lu, J. D. Hunt, P. Gilgien, W. Kurz, Cellular and dendritic array growth in rapidly solidified Al-Fe and Al-Si alloys, Acta Metallurgica et Materialia, 42 (1994), 1653–1660