6H to 3C Polytypic Transformation in SiC Ceramics During Brazing Process

Abstract

Abstract: In this paper, pure Ni foil was used as an intermediate layer to achieve brazing connection of 6H-SiC at 1 100~1 245 ℃. The microstructure of the brazed joint and the interface between the brazed joint and the 6H-SiC substrate were studied to investigate the effect of brazing process on the crystal structure of SiC ceramics and provide theoretical and experimental data supports for brazing process design. The results show that a small amount of Ni atoms diffuse into the 6H-SiC ceramics during the brazing process and exist in solid solution form, which reduces the dislocation energy of 6H-SiC. The residual stress at the 6H-SiC/brazed joint interface increases with the increase of brazing temperature, and when the brazing temperature reaches 1 245 ℃, the (0001) plane of 6H-SiC at the interface slips along the 1/3 <1100> direction, and the 6H-SiC is sheared to form 3C-SiC. Therefore, SiC ceramics can undergo phase transformation under the influence of stress and brazing material composition during the brazing process, and the effect of brazing process on their crystal structure and properties should be considered for SiC ceramics used in special environments.

Key words: 6H-SiC, 3C-SiC, phase transformation, brazing, residual stress

CLC Number:

O469

SHI Haojiang, ZHANG Ruiqian, LI Ming, YAN Jiazhen, LIU Zihao, BAI Dong. 6H to 3C Polytypic Transformation in SiC Ceramics During Brazing Process[J]. Journal of Synthetic Crystals, 2023, 52(8): 1516-1522.

References

[1] VLASKINA S I. 3C-6H transformation in heated cubic silicon carbide 3C-SiC[J]. Semiconductor Physics Quantum Electronics and Optoelectronics, 2011, 14(4): 432-436.
[2] VLASKINA S I, BUSINKAA@MAIL RU E M. Silicon carbide phase transition in as-grown 3C-6H polytypes junction[J]. Semiconductor Physics Quantum Electronics and Optoelectronics, 2013, 16(2): 132-135.
[3] PARISH C M, KOYANAGI T, KONDO S, et al. Irradiation-induced β to α SiC transformation at low temperature[J]. Scientific Reports, 2017, 7: 1198.
[4] ZHU B, ZHAO D, ZHAO H W. A study of deformation behavior and phase transformation in 4H-SiC during nanoindentation process via molecular dynamics simulation[J]. Ceramics International, 2019, 45(4): 5150-5157.
[5] YANG J W, PIROUZ P. The α → β polytypic transformation in high-temperature indented SiC[J]. Journal of Materials Research, 1993, 8(11): 2902-2907.
[6] SHI H J, CHAI Y D, LI N, et al. Interfacial reaction mechanism of SiC joints joined by pure nickel foil[J]. Journal of the European Ceramic Society, 2020, 40(15): 5162-5171.
[7] GUZMÁN DE VILLORIA R, MIRAVETE A. Mechanical model to evaluate the effect of the dispersion in nanocomposites[J]. Acta Materialia, 2007, 55(9): 3025-3031.
[8] SENGUPTA P, SAHOO S S, BHATTACHARJEE A, et al. Effect of TiC addition on structure and properties of spark plasma sintered ZrB₂-SiC-TiC ultrahigh temperature ceramic composite[J]. Journal of Alloys and Compounds, 2021, 850: 156668.
[9] ZHAO Y H, HOU H, ZHAO Y H, et al. First-principles study of the nickel-silicon binary compounds under pressure[J]. Journal of Alloys and Compounds, 2015, 640: 233-239.
[10] GEENEN F A, KNAEPEN W, MOENS F, et al. Anisotropic thermal expansion of Ni, Pd and Pt germanides and silicides[J]. Journal of Physics D: Applied Physics, 2016, 49(27): 275307.
[11] KIEWEL H, BUNGE H J, FRITSCHE L. Effect of orientation correlation on the elastic constants of polycrystalline materials[J]. Textures and Microstructures, 1996, 28(1/2): 105-120.
[12] KELLY B T, WALKER P L. Theory of thermal expansion of a graphite crystal in the semi-continuum model[J]. Carbon, 1970, 8(2): 211-226.
[13] JEPPS N W, PAGE T F. Polytypic transformations in silicon carbide[J]. Progress in Crystal Growth and Characterization, 1983, 7(1/2/3/4): 259-307.
[14] WHITNEY E D, SHAFFER P T B. Investigation of the phase transformation between alpha- and beta-silicon carbide at high pressures[J]. High Temperatures-High Pressures, 1969,1(1):107-110.
[15] SOKHOR M I, KONDAKOV V G, FELDGUN L I. Transition of silicon carbide from the hexagonal to the cubic phase under the influence of high pressures and high temperatures[J]. Soviet Physics Doklady, 1967, 175(4): 826.
[16] MEDVEDEVA N I, YURYEVA É I, IVANOVSKII A L. Titanium, vanadium, and nickel impurities in 3C-SiC: electronic structure and lattice relaxation effects[J]. Semiconductors, 2002, 36(7): 751-754.
[17] YURYEVA E I, IVANOVSKII A L. Electronic structure and chemical bonding of nickel impurities in cubic silicon carbide[J]. Russian Journal of Coordination Chemistry, 2002, 28(12): 881-888.