A Comparative Study of the γ/γ' Eutectic Evolution During the Solidification of Ni-Base Superalloys

被引：87
作者：
Seo, S. M. [1 ]
Lee, J. H. [2 ]
Yoo, Y. S. [1 ]
Jo, C. Y. [1 ]
Miyahara, H. [3 ]
Ogi, K. [4 ]
机构：
[1] Korea Inst Mat Sci, High Temp Mat Grp, Chang Won 641010, South Korea
[2] Changwon Univ, Dept Met & Mat Engn, Chang Won 641773, South Korea
[3] Kyushu Univ, Dept Mat Sci & Engn, Fukuoka 8190395, Japan
[4] Oita Natl Coll Technol, Oita 8700152, Japan
来源：
METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE | 2011年 / 42A卷 / 10期
基金：
日本学术振兴会;
关键词：
SINGLE-CRYSTAL SUPERALLOY; SOLUTE REDISTRIBUTION; PB-SN; MICROSEGREGATION; MICROSTRUCTURE; SEGREGATION; ALLOYS; PHASE; MACROSEGREGATION; COEFFICIENTS;
D O I：
10.1007/s11661-011-0738-4
中图分类号：
T [工业技术];
学科分类号：
08 ;
摘要：
The evolution of gamma/gamma' eutectic during the solidification of Ni-base superalloys CMSX-10 and CMSX-4 was investigated over a wide range of cooling rates. The microsegregation behavior during solidification was also quantitatively examined to clarify the influence of elemental segregation on the evolution of gamma/gamma' eutectic. In the cooling rate ranges investigated (0.9 to 138.4 K/min (0.9 to 138.4 A degrees C/min)), the gamma/gamma' eutectic fraction in CMSX-10 was found to be more than 2 times higher than that in CMSX-4 at a given cooling rate. However, the dependence of the gamma/gamma' eutectic fraction on the cooling rate in both alloys showed a similar tendency; i.e., the gamma/gamma' eutectic fraction increased with increasing the cooling rate and then exhibited a maximum plateau at and above the certain critical cooling rate in both alloys. This critical cooling rate was found to be dependent on the alloy composition and was estimated to be about 12 K/min (12 A degrees C/min) and 25 K/min (25 A degrees C/min) for CMSX-10 and CMSX-4, respectively. The calculated solid compositions based on the modified Scheil model revealed that even a small compositional difference of total gamma' forming elements in the initial composition of the alloy can play a significant role in the as-cast eutectic fraction during the solidification of Ni-base superalloys. The evolution of the gamma/gamma' eutectic fraction with respect to the cooling rate could be rationalized by taking into account the effects of back-diffusion in solid and dendrite arm coarsening on decreasing the extent of microsegregation.
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页码：3150 / 3159
页数：10
相关论文
共 40 条
[1]  
Bhambri A. K., 1975, Metallurgical Transactions B (Process Metallurgy), V6B, P523, DOI 10.1007/BF02913844
[2]  
BRODY HD, 1966, T METALL SOC AIME, V236, P615
[3]   The segregation of elements in high-refractory-content single-crystal nickel-based superalloys [J].
Caldwell, EC ;
Fela, FJ ;
Fuchs, GE .
JOM, 2004, 56 (09) :44-48
[4]   Process modelling of grain selection during the solidification of single crystal superalloy castings [J].
Carter, P ;
Cox, DC ;
Gandin, CA ;
Reed, RC .
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING, 2000, 280 (02) :233-246
[5]   SOLUTE REDISTRIBUTION DURING SOLIDIFICATION WITH RAPID SOLID-STATE DIFFUSION [J].
CLYNE, TW ;
KURZ, W .
METALLURGICAL TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE, 1981, 12 (06) :965-971
[6]   ORIGIN OF FRECKLES IN UNIDIRECTIONALLY SOLIDIFIED CASTINGS [J].
COPLEY, SM ;
GIAMEI, AF ;
JOHNSON, SM ;
HORNBECK.MF .
METALLURGICAL TRANSACTIONS, 1970, 1 (08) :2193-&
[7]   Two-dimensional modelling and experimental study on microsegregation during solidification of an Al-Cu binary alloy [J].
Du, Q. ;
Eskin, D. G. ;
Jacot, A. ;
Katgerman, L. .
ACTA MATERIALIA, 2007, 55 (05) :1523-1532
[8]   Influence of rhenium and cooling rate on the solidification of Ni base superalloys, Inconel 718 [J].
El-Bagoury, N ;
Yamamoto, K ;
Miyahara, H ;
Ogi, K .
MATERIALS TRANSACTIONS, 2005, 46 (05) :909-915
[9]   Experimental study of structure formation in binary Al-Cu alloys at different cooling rates [J].
Eskin, D ;
Du, Q ;
Ruvalcaba, D ;
Katgerman, L .
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING, 2005, 405 (1-2) :1-10
[10]   Coarsening in solidification processing [J].
Flemings, MC .
MATERIALS TRANSACTIONS, 2005, 46 (05) :895-900
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