Microstructure and Corrosion Behavior of Brazed Joints of SiC/SiC Composites and Hastelloy N Alloy Using Cu-Ni Alloy

doi:10.15541/jim20210381

Abstract

Abstract:

SiC fibers reinforced SiC ceramic matrix composites were brazed to Hastelloy N alloy using Cu-2.67Ni (mass percentage) alloy. The obtained joints were corroded in FLiNaK molten salt at 800 ℃for 100 h. Microstructure evolution and corrosion behavior of joints were characterized. Alloy elements, e.g. Ni, Cr and Mo, diffuse from Hastelloy N alloy into Cu-Ni joint seam, while the Si element in SiC/SiC composites diffuses into joint seam even the Hastelloy N alloy. Cr element enriches near the interface between SiC composites and joint alloy to form discontinuity interlayer, which acts as the active metal instead of Ni. Higher temperature contributes to both the diffusion process and the erosion of SiC by Ni, and lower temperature would lead to the incomplete fusion of brazing fillers. The diffusion of elements during the brazing changes the composition of the joint seam and Hastelloy N alloy, which caused the deterioration of corrosion resistance of alloy. The selective corrosion of Cr and Si, supported by thermodynamic calculation, results in the corrosion of both joint seam and alloy.

Key words: SiC/SiC composites, Hastelloy N alloy, Cu-Ni alloy, brazing joint, corrosion behavior

CLC Number:

TQ174

WANG Hongda, FENG Qian, YOU Xiao, ZHOU Haijun, HU Jianbao, KAN Yanmei, CHEN Xiaowu, DONG Shaoming. Microstructure and Corrosion Behavior of Brazed Joints of SiC/SiC Composites and Hastelloy N Alloy Using Cu-Ni Alloy[J]. Journal of Inorganic Materials, 2022, 37(4): 452-458.

Figures/Tables 9

Fig. 1 Schematic illustration of the sandwich-like structure of joint

Fig. 2 SEM images of brazing joints obtained at (a) 1090, (b) 1110 ℃, (c) and (d) 1130 ℃, correspoding EDS analyses (atom fraction) (e) of the point in image (d)

Fig. 3 Elemental distribution analyses by EDS of joint obtained at 1130 ℃

Fig. 4 Gibbs free energy of formation of candidates calculated using HSC Chemistry 5.11 computer software and its associated databases

Fig. 5 SEM image of microstructure and EDS line-scan analyses in SiC/SiC composites near joint obtained at 1150 ℃

Fig. 6 XRD patterns of joints before and after corrosion

Fig. 7 Appearance images and SEM images of microstructure of joints before and after corrosion at 800 ℃ for 100 h

Fig. 8 Elemental distribution analyses by EDS of joint obtained at 1130 ℃ after corrosion at 800 ℃ for 100 h

Table 1 Content of main metal impurities in fluoride salts before and after corrosion (10-4% in mass)

Element	Before corrosion	After corrosion
Ni	10	20
Cr	20	210
Fe	30	40
Mo	<10	<10

References 29

[1]	KRENKEL W. Ceramic Matrix Composites: Fiber Reinforced Ceramics and their Applications. Weinheim: John Wiley & Sons, 2008.
[2]	PI H, SONG F, WANG H, et al. Influence of copper contamination on ablation damage of C/SiC composites under simulated thermal environment of arc heater. Ceramics International, 2021, 47(15): 22016-22024. DOI URL
[3]	LEE K N, MILLER R A. Oxidation behavior of muilite-coated SiC and SiC/SiC composites under thermal cycling between room temperature and 1200 ℃-1400 ℃. Journal of the American Ceramic Society, 1996, 79(3): 620-626. DOI URL
[4]	GOMINA M, FOURVEL P, ROUILLON M H. High temperature mechanical behaviour of an uncoated SiC-SiC composite material. Journal of Materials Science, 1991, 26(7): 1891-1898. DOI URL
[5]	JACOBSEN T K, BR NDSTED P. Mechanical properties of two plain-woven chemical vapor infiltrated silicon carbide-matrix composites. Journal of the American Ceramic Society, 2001, 84(5): 1043-1051. DOI URL
[6]	KATOH Y, OZAWA K, HINOKI T, et al. Mechanical properties of advanced SiC fiber composites irradiated at very high temperatures. Journal of Nuclear Materials, 2011, 417(1): 416-420. DOI URL
[7]	JONES R H, HENAGER C H. Fusion reactor application issues for low activation SiC/SiC composites. Journal of Nuclear Materials, 1995, 219(2): 55-62. DOI URL
[8]	HE X, SONG J, TAN J, et al. SiC coating: an alternative for the protection of nuclear graphite from liquid fluoride salt. Journal of Nuclear Materials, 2014, 448(1): 1-3. DOI URL
[9]	NISHIMURA H, TERAI T, YONEOKA T, et al. Compatibility of structural candidate materials with LiF-BeF₂ molten salt mixture. Journal of Nuclear Materials, 2000, 283-287(Part 2): 1326-1331. DOI URL
[10]	YANG X, LIU M, GAO Y, et al. Effect of oxygen on the corrosion of SiC in LiF-NaF-KF molten salt. Corrosion Science, 2016, 103: 165-172. DOI URL
[11]	WANG H, ZHOU H, DONG S, et al. Corrosion behavior of SiC_f/SiC composites in high temperature fluoride salt environment. Journal of Inorganic Materials, 2017, 32(11): 1133-1140. DOI URL
[12]	RICCARDI B, GIANCARLI L, HASEGAWA A, et al. Issues and advances in SiC_f/SiC composites development for fusion reactors. Journal of Nuclear Materials, 2004, 329-333(Part A): 56-65. DOI URL
[13]	WILLIAMS D F, TOTH L M, CLARNO K T. ORNL/TM-2006/12. Oak Ridge: Oak Ridge National Lab., 2006.
[14]	HENAGER C H, SHIN Y, BLUM Y, et al. Coatings and joining for SiC and SiC-composites for nuclear energy systems. Journal of Nuclear Materials, 2007, 367-370: 1139-1143. DOI URL
[15]	ZHANG Y, FENG D, HE Z Y, et al. Progress in joining ceramics to metals. Journal of Iron and Steel Research, 2006, 13(2): 1-5.
[16]	SINGH M, ASTHANA R, SHPARGEL T P. Brazing of ceramic- matrix composites to Ti and Hastealloy using Ni-base metallic glass interlayers. Materials Science and Engineering: A, 2008, 498(1): 19-30. DOI URL
[17]	HATTALI M L, VALETTE S, ROPITAL F, et al. Study of SiC- nickel alloy bonding for high temperature applications. Journal of the European Ceramic Society, 2009, 29(4): 813-819. DOI URL
[18]	LIN G, HUANG J, ZHANG H. Joints of carbon fiber-reinforced SiC composites to Ti-alloy brazed by Ag-Cu-Ti short carbon fibers. Journal of Materials Processing Technology, 2007, 189(1): 256-261. DOI URL
[19]	XIONG H, LI X, MAO W, et al. Wetting behavior of Co based active brazing alloys on SiC and the interfacial reactions. Materials Letters, 2003, 57(22): 3417-3421. DOI URL
[20]	LU J, XIA Z. The corrosion performance of a binary Cu-Ni Alloy used as an anode for aluminum electrolysis. Applied Mechanics & Materials, 2011, 55: 7-10.
[21]	PARK J S, LANDRY K, PEREPEZKO J H. Kinetic control of silicon carbide/metal reactions. Materials Science and Engineering: A, 1999, 259(2): 279-286. DOI URL
[22]	FRANKE P, NEUSCH TZ D. Cu-NiCopper- Nickel//FRANKE P, NEUSCH TZ D. Cu-Ni(Copper- Nickel)//FRANKE P, NEUSCH TZ D. Binary systems Part 3: Binary Systems from Cs- K to Mg-Zr Heidelberg; Springer. 2005.
[23]	ARAKI H, SUZUKI H, YANG W, et al. Effect of high temperature heat treatment in vacuum on microstructure and bending properties of SiC_f/SiC composites prepared by CVI. Journal of Nuclear Materials, 1998, 258-263(Part 2): 1540-1545. DOI URL
[24]	OLSON L C, AMBROSEK J W, SRIDHARAN K, et al. Evaluation of Material Corrosion in Molten Fluoride Salt. Proceedings of the Presentation on AIChE Conference, San-Francisco, F, 2006.
[25]	XIONG H P, CHEN B, KANG YS, et al. Wettability of Co-V, and PdNi-Cr-V system alloys on SiC ceramic and interfacial reactions. Scripta Materialia, 2007, 56(2): 173-176. DOI URL
[26]	OLSON L C, AMBROSEK J W, SRIDHARAN K, et al. Materials corrosion in molten LiF-NaF-KF salt. Journal of Fluorine Chemistry, 2009, 130(1): 67-73. DOI URL
[27]	SCHMIDT J, SCHEIFFELE M, CRIPPA M, et al. Design, fabrication, and testing of ceramic plat-type heat exchangers with integrated flow channel design. International Journal of Applied Ceramic Technology, 2011, 8(5): 1073-1086. DOI URL
[28]	SELLERS R S, CHENG W J, ANDERSON M H, et al. Materials Corrosion in Molten LiF-NaF-KF Eutectic Salt under Different Reduction-oxidation Conditions. Proceedings of the International Conference Advances in Nuclear Power Plants (ICAPP’12), F, 2012.
[29]	OZERYANAYA I N. Corrosion of metals by molten salts in heat- treatment processes. Metal Science and Heat Treatment, 1985, 27(3): 184-188. DOI URL