EFFECT OF Hf ON THE INTERFACIAL REACTION BETWEEN A NICKEL BASE SUPERALLOY AND A CERAMIC MATERIAL
CHEN Xiaoyan, ZHOU Yizhou(), ZHANG Chaowei, JIN Tao, SUN Xiaofeng
Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016
Cite this article:
CHEN Xiaoyan, ZHOU Yizhou, ZHANG Chaowei, JIN Tao, SUN Xiaofeng. EFFECT OF Hf ON THE INTERFACIAL REACTION BETWEEN A NICKEL BASE SUPERALLOY AND A CERAMIC MATERIAL. Acta Metall Sin, 2014, 50(8): 1019-1024.
The influence of Hf content on the wettability and interfacial reaction between a nickel base superalloy and a ceramic material was investigated by using a sessile drop method. The wetting angle was measured through the geometric parameters of the metal drop. The interfacial morphology and elements distribution were studied by SEM and EPMA, respectively. XPS was employed to study the phase formation at the metal-ceramic interface. The relationship between wettability and interfacial reaction was discussed. It was found that the wetting angle of the metal drop on the ceramic substrate was decreased with increasing Hf content in the alloy and the wettability of the studied superalloy on the ceramic material was enhanced with increasing Hf content in the alloy. When the content of Hf increased from 0.1% to 2.0% (mass fraction), the wetting angle decreased from 132° to 112°. The interfacial reaction led to a sharp decrease in wetting angle as Hf content was 1.5%. The product of interfacial reaction was HfO2 and the thermodynamic analysis indicated that Hf was able to substitute Si in SiO2 in the ceramic material.
Fund: Supported by National Natural Science Foundation of China (Nos.U1037601, 51271186, 51331005, 11332010 and 51001103), National Basic Research Program of China (No.2010CB631206), Fund of the State Key Labortary of Advanced Technologies for Comprehensive Utilization of Platinum Metals (No.SKL-SPM-201213)
Fig.1 Optical micrographs and schematic diagram showing measurement method of wetting angle θ between the studied alloy and ceramic material (r and d—the radius and diameter of the alloy drop bottom, h—the height of the drop)
(a) before melting of the alloy
(b) after melting of the alloy
(c) measurement of wetting angle θ
Fig.2 Effects of Hf on the wetting angle between superalloy melt and ceramic material
Fig.3 Macrographs of the studied alloys after melting (The numbers in Fig.3a are the contents of Hf, mass fraction, %)
Fig.4 SEM images showing the microstructure of reaction area between A7 alloy and ceramic material
(a) general view of the metal drop bottom
(b) detailed microstructure of the reaction area
(c) interface of A7 alloy and ceramic material
(d) detailed microstructure of the white rectangle region in Fig.4c
Fig.5 EPMA analysis of elemental distribution within the reaction area and XPS analysis of the reaction product on the bottom of A7 alloy
(a) SEM image (b) distribution map of Hf (c) distribution map of O
(d) electron binding energy of Hf determined from rectangle region in Fig.5a
Element (compound)
/(kJ·mol-1)
/(J·mol-1)
T / K
a
b
c
d
Hf
0
43.56
23.460
7.623
0
0
298~2013
SiO2
-908.35
43.40
71.626
1.891
-39.058
0
298~2000
HfO2
-1113.2
59.36
72.111
9.050
-12.941
0
298~1973
Si
0
18.82
22.824
8.238
-2.063
0
1685~3492
Table 1 Thermodynamic parameters used for the calculation[24]
[1]
Jones S, Yuan C. J Mater Process Technol, 2003; 135: 258
[2]
Duarte T P, Neto R J, Felix R, Lino F J. Mater Sci Forum, 2008; 587-588: 157
[3]
Gong R C. Foundry Technol, 2005; 26: 523
(龚荣昌. 铸造技术, 2005; 26: 523)
[4]
Mehan R L, Bolan R B. J Mater Sci, 1979; 14: 2471
[5]
Slabkii V D, Traktuev O M, Khrulev A A, Yurovskikh Y N. At Energ, 2000; 88: 274
[6]
Bruce E T, Michael C. US Pat, 4244551, 1981
[7]
Topygo V K, Murphy K S, Clarke D R. Acta Mater, 2008; 56: 489
[8]
Orlov M R. Russ Metall, 2008; 1: 70
[9]
Xue M. Master Thesis, Qinghua University, Beijing, 2007
(薛 明. 清华大学硕士学位论文, 北京, 2007)
[10]
Zheng L, Xiao C B, Zhang G Q, Gu G H, Li X, Liu X G, Xue M, Tang D Z. J Aero Mater, 2012; 32(3): 10
