In Situ Reaction Strengthening and Toughening of B₄C/TiSi₂ Ceramics

Abstract

B₄C-SiC-TiB₂ ceramics were prepared by in situ reactive hot-pressing sintering with TiSi₂ as an additive. The reaction pathways of TiSi₂ and B₄C were investigated. The sintering was found to be a multi-step process. The reaction started at approximately 1 000 °C, and TiB₂ was formed first. Part of Si and C started to react at 1 300 °C, and the unreacted Si melted at 1 400 °C to form a liquid phase. TiSi₂ predominantly affected the intermediate sintering process of B₄C and increased the sintering rate. Due to the unique reaction process of TiSi₂ and B₄C, a large number of aggregates composed of SiC and TiB₂ were generated. The results showed that composite ceramics with the optimal flexural strength of 807 MPa, fracture toughness of 3.2 MPa·m^1/2, and hardness of 32 GPa, were obtained when the TiSi₂ content was 10 wt%.

Keywords

in situ reaction / hot pressing sintering / TiSi₂ / B₄C composite ceramics / reaction mechanism

References

[1] Thévenot F. Boron Carbide-a Comprehensive Review[J]. J. Eur. Ceram. Soc., 1990, 6(4): 205-225.

[2] Suri AK, Subramanian C, Snober JK, et al. Synthesis and Consolidation of Boron Carbide: A Review[J]. Int. Mater. Rev., 2010, 55(1): b4-40.

[3] Wang S, Xing P, Gao S, et al. Effect of in-situ Formed CrB₂ on Pressureless Sintering of B₄C[J]. Ceram. Int., 2018, 44(16): 20 367-20 374.

[4] Rehman SS, Wei J, Fu Z, et al. In situ Synthesis and Sintering of B₄C/ZrB₂ Composites from B₄C and ZrH₂ Mixtures by Spark Plasma Sintering[J]. J. Eur. Ceram. Soc., 2015, 35(4): 1 139-1 145.

[5] Xiong Y, Du X, Xiang M, et al. Densification Mechanism during Reactive Hot Pressing of B₄C-ZrO₂ Mixtures[J]. J. Eur. Ceram. Soc., 2018, 38(12): 4 167-4 172.

[6] Tang J, Ji W, Xie J, et al. Fine and High-performance B_6.5C-TiB₂-SiC-BN Composite Fabricated by Reactive Hot Pressing Via TiCN-B-Si Mixture[J]. Ceram. Int., 2020, 46(8): 11 013-11 020.

[7] Deng JX, Sun JLX. Microstructure and Mechanical Properties of Hot-pressed B₄C/TiC/Mo Ceramic Composites[J]. Ceram. Int., 2009, 35(2): 771-778.

[8] Wang S, Gao S, Xing P, et al. Pressureless Liquid-phase Sintering of B₄C with MoSi₂ as a Sintering Aid[J]. Ceram. Int., 2019, 45(10): 13 502-13 508.

[9] Zhang ZX, Xu CJ, Du XW, et al. Synthesis Mechanism and Mechanical Properties of TiB₂-SiC Composites Fabricated with the B₄C-TiC-Si System by Reactive Hot Pressing[J]. J. Alloys Compd., 2015, 619: 26-30.

[10] Cao YQ, He QL, Wang WM, et al. Microstructure, Mechanical, and Thermal Properties of B₄C-TiB₂-SiC Composites Prepared by Reactive Hot-pressing[J]. J. Wuhan Univ. Technol., 2020, 35: 1 031-1 037.

[11] Moshtaghioun BM, Ortiz AL, Gómez-Garcja D, et al. Toughening of Super-hard Ultra-fine Grained B₄C Densified by Spark-plasma Sintering Via SiC Addition[J]. J. Eur. Ceram. Soc., 2013, 33(8): 1 395-1 401.

[12] Zorzi JE, Perottoni CA, da Jornada JAH. Hardness and Wear Resistance of B₄C Ceramics Prepared with Several Additives[J]. Mater. Lett., 2005, 59(23): 2 932-2 935.

[13] Yamada S, Hirao K, Yamauchi Y, et al. High Strength B₄C-TiB₂ Composites Fabricated by Reaction Hot-pressing[J]. J. Eur. Ceram. Soc., 2003, 23(7): 1 123-1 130.

[14] Zhang XH, Li WJ, Hong CQ, et al. Microstructure and Mechanical Properties of ZrB₂-based Composites Reinforced and Toughened by Zirconia[J]. Int. J. Appl. Ceram. Technol., 2008, 5(5): 499-504.

[15] Gutmanas EY, Gotman I. Reactive Synthesis of Ceramic Matrix Composites under Pressure[J]. Ceram. Int., 2000, 26(7): 699-707.

[16] Hoke DA, Kim DK, Lasalvia JC, et al. Combustion Synthesis/Dynamic Densification of TiB₂-SiC Composite[J]. J. Am. Ceram. Soc., 1996, 79(1): 177-182.

[17] Raju GB, Basu B. Densification, Sintering Reactions, and Properties of Titanium Diboride with Titanium Disilicide as a Sintering Aid[J]. J. Am. Ceram. Soc., 2007, 90(11): 3 415-3 423.

[18] Liu GQ, Chen SX, Zhao YW, et al. Effect of Ti and Its Compounds on the Mechanical Properties and Microstructure of B₄C Ceramics Fabricated Via Pressureless Sintering[J]. Ceram. Int., 2021, 47(10): 13 756-13 761.

[19] Xu CM, Hong Z, Zhang GJ. Pressureless Sintering of Boron Carbide Ceramics with Al-Si Additives[J]. Int. J. Refract. Met. H, 2013, 41: 2-6.

[20] Du XW, Wang Y, Zhang ZX, et al. Effects of Silicon Addition on the Microstructure and Properties of B₄C-SiC Composite Prepared with Polycarbosilane-coated B₄C Powder[J]. Mater. Sci. Eng. A, 2015, 636: 133-137.

[21] King DS, Fahrenholtz WG, Hilmas GE. Silicon Carbide-titanium Diboride Ceramic Composites[J]. J. Eur. Ceram. Soc., 2013, 33(15–16): 2 943-2 951.

[22] Zhang XR, Zhang ZX, Wang WM, et al. Microstructure and Mechanical Properties of B₄C-TiB₂-SiC Composites Toughened by Composite Structural Toughening Phases[J]. J. Am. Ceram. Soc., 2017, 100(7): 3 099-3 107.

[23] Zhang XR, Zhang ZX, Liu YM, et al. High-performance B4C-TiB₂-SiC Composites with Tuneable Properties Fabricated by Reactive Hot Pressing[J]. J. Eur. Ceram. Soc., 2019, 39(10): 2 995-3 002.