The fabrication of Si3N4 ceramics typically requires high temperatures (above 1700 °C) and prolonged sintering time to achieve densification, resulting in high energy consumption and increased manufacturing costs. Moreover, reports on the fabrication of dense Si3N4 ceramics with good mechanical properties under MPa-level pressure and low temperatures are rare. In this work, we propose a low-temperature rapid spark plasma sintering strategy involving the introduction of fine-grained β-Si3N4 powder with high lattice strain energy as an “additive”. Dense biphasic Si3N4 ceramics, predominantly α-Si3N4, were successfully fabricated at a mechanical pressure of 200 MPa and a temperature of 1300 °C, achieving a relative density of 97%. The application of high pressure promoted particle rearrangement and uniform liquid‒phase distribution, providing additional driving forces for sintering. The introduction of β-Si3N4 seeds facilitated an in-situ solution–reprecipitation process, enabling rapid densification with a minimal liquid phase and without significant grain growth, resulting in nanometer-scale grains. The Si3N4 sample prepared at 1350 °C exhibited a desirable combination of high hardness (18.5
Riley FL. Silicon nitride and related materials. J Am Ceram Soc 2000, 83: 245–265.
Zhang J, Liu GH, Cui W, et al. Plastic deformation in silicon nitride ceramics via bond switching at coherent interfaces. Science 2022, 378: 371–376.
Krstic Z, Krstic VD. Silicon nitride: The engineering material of the future. J Mater Sci 2012, 47: 535–552.
Xue WJ, Yi J, Xie ZP, et al. Enhanced fracture toughness of silicon nitride ceramics at cryogenic temperatures. Scripta Mater 2012, 66: 891–894.
Du XY, Lee SS, Blugan G, et al. Silicon nitride as a biomedical material: An overview. Int J Mol Sci 2022, 23: 6551.
Kondo N, Asayama M, Suzuki Y, et al. High-temperature strength of sinter-forged silicon nitride with Lutetia additive. J Am Ceram Soc 2003, 86: 1430–1432.
Zhao S, Du SM, Sun SY, et al. Synthesis of spherical Si3N4 powders by liquid-phase modified carbothermal reduction and nitridation. J Am Ceram Soc 2024, 107: 16–23.
Han Y, Xie ZP, Li S, et al. Optimum sintering temperature of high quality silicon nitride ceramics under oscillatory pressure. Ceram Int 2018, 44: 6949–6952.
Yang JF, Ohji T, Niihara K. Influence of yttria–alumina content on sintering behavior and microstructure of silicon nitride ceramics. J Am Ceram Soc 2000, 83: 2094–2096.
Kingery WD. Densification during sintering in the presence of a liquid phase. I. Theory. J Appl Phys 1959, 30: 301–306.
Sharma V, Nemat-Nasser S, Vecchio KS. Effect of grain-boundary phase on dynamic compression fatigue in hot-pressed silicon nitride. J Am Ceram Soc 1998, 81: 129–139.
Ziegler G, Heinrich J, Wötting G. Relationships between processing, microstructure and properties of dense and reaction-bonded silicon nitride. J Mater Sci 1987, 22: 3041–3086.
Du SM, Zhang J, Li F, et al. Rapid fabrication of Si3N4 ceramics with gradient appearance and microstructure. J Am Ceram Soc 2023, 106: 7611–7617.
Imamura H, Kawata T, Honda S, et al. Thermal conductivity improvement in silicon nitride ceramics via grain purification. J Am Ceram Soc 2024, 107: 1159–1169.
Zhang J, Cui W, Li F, et al. Effects of MgSiN2 addition and post-annealing on mechanical and thermal properties of Si3N4 ceramics. Ceram Int 2020, 46: 15719–15722.
Xu X, Nishimura T, Hirosaki N, et al. Fabrication of a nano-Si3N4/nano-C composite by high-energy ball milling and spark plasma sintering. J Am Ceram Soc 2007, 90: 1058–1062.
Bake A, Hakeem AS, Ahmed BA, et al. Effect of nano- and micro-sized Si3N4 powder on phase formation, microstructure and properties of β′-SiAlON prepared by spark plasma sintering. Ceram Int 2022, 48: 1916–1925.
Yang M, Wang Q, Lv ML, et al. Synthesis and sintering of silicon nitride nano-powders via sodium reduction in liquid ammonia. J Eur Ceram Soc 2016, 36: 1899–1904.
Xu X, Nishimura T, Hirosaki N, et al. New strategies for preparing nanosized silicon nitride ceramics. J Am Ceram Soc 2005, 88: 934–937.
Matovic B, Rixecker G, Aldinger F. Densification of Si3N4 with LiYO2 additive. J Am Ceram Soc 2004, 87: 546–549.
Luo J, Li JG, Li MJ, et al. Low-temperature densification by plasma activated sintering of Mg2Si-added Si3N4. Ceram Int 2019, 45: 15128–15133.
Luo CX, Zhang YX, Deng TF. Pressureless sintering of high performance silicon nitride ceramics at 1620 °C. Ceram Int 2021, 47: 29371–29378.
Yang HB, Wang BM, Zhang H, et al. Evolving corundum nanoparticles at room temperature. Acta Mater 2023, 255: 119038.
Wen QB, Yu ZJ, Riedel R. The fate and role of in situ formed carbon in polymer-derived ceramics. Prog Mater Sci 2020, 109: 100623.
Johnston NR, Strobel SA. Principles of fluoride toxicity and the cellular response: A review. Arch Toxicol 2020, 94: 1051–1069.
Gasch MJ, Wan J, Mukherjee AK. Preparation of a Si3N4/SiC nanocomposite by high-pressure sintering of polymer precursor derived powders. Scripta Mater 2001, 45: 1063–1068.
Jia HS, Li JQ, Niu R, et al. Fabrication of β-Si3N4 with high thermal conductivity under ultra-high pressure. Ceram Int 2018, 44: 23288–23292.
Ma SL, Zhao YS, Tang RL, et al. Transparent β-Si3N4 and γ-Si3N4 compacts synthesized with mixed-size precursor under high pressure and high temperature. Appl Phys Lett 2021, 119: 171904.
Ratzker B, Sokol M. Exploring the capabilities of high-pressure spark plasma sintering (HPSPS): A review of materials processing and properties. Mater Des 2023, 233: 112238.
Miranzo P, González-Julián J, Osendi MI, et al. Enhanced particle rearrangement during liquid phase spark plasma sintering of silicon nitride-based ceramics. Ceram Int 2011, 37: 159–166.
Jeong K, Tatami J, Iijima M, et al. Spark plasma sintering of silicon nitride using nanocomposite particles. Adv Powder Technol 2017, 28: 37–42.
Govindasamy L, Park YJ, Ko JW, et al. Role of β-Si3N4 seeds in microstructure development and properties of silicon nitride ceramics: A comprehensive review. J Korean Ceram Soc 2024, 61: 507–536.
Huang JW, Lv XA, Dong XF, et al. Synergistic reinforcement of Si3N4 based ceramics fabricated via multiphase strengthening under low temperature and short holding time. Materials 2023, 16: 6163.
Xiong H, Li B, Xi XA, et al. Preparation of graded silicon nitride ceramics with high mechanical performance using β-Si3N4 seeds. Ceram Int 2023, 49: 36528–36535.
Lee CH, Lu HH, Wang CG, et al. Microstructure and fracture behavior of β-Si3N4 based nanoceramics. Ceram Int 2011, 37: 641–645.
Du SM, Zhang J, Li F, et al. Low temperature fabrication of highly dense α-Si3N4 ceramics. J Am Ceram Soc 2024, 107: 4494–4500.
Wang B, Jiang QG, Liu WY, et al. Fabrication of fine-grained α/β Si3N4 by hot pressing flowing sintering at 1550 °C. Ceram Int 2019, 45: 13958–13963.
Ratzker B, Sokol M, Kalabukhov S, et al. High-pressure spark plasma sintering of silicon nitride with LiF additive. J Eur Ceram Soc 2018, 38: 1271–1277.
Kumar K, Kim MJ, Oh HM, et al. Fabrication of highly dense Si3N4 via record low-content additive system for low-temperature pressureless sintering. J Am Ceram Soc 2022, 105: 4669–4680.
Niihara K. A fracture mechanics analysis of indentation-induced Palmqvist crack in ceramics. J Mater Sci Lett 1983, 2: 221–223.
Niihara K, Morena R, Hasselman DPH. Evaluation of KIC of brittle solids by the indentation method with low crack-to-indent ratios. J Mater Sci Lett 1982, 1: 13–16.
Gazzara C, Messier D. Determination of phase content of Si3N4 by X-ray diffraction analysis. Am Ceram Soc Bull 1977, 56: 777–780.
Hampshire S, Nestor E, Flynn R, et al. Yttrium oxynitride glasses: Properties and potential for crystallisation to glass-ceramics. J Eur Ceram Soc 1994, 14: 261–273.
Saito N, Kai K, Furusho S, et al. Properties of nitrogen-containing yttria–alumina–silica melts and glasses. J Am Ceram Soc 2003, 86: 711–716.
Sayyadi-Shahraki A, Rafiaei SM, Ghadami S, et al. Densification and mechanical properties of spark plasma sintered Si3N4/ZrO2 nano-composites. J Alloys Compd 2019, 776: 798–806.
Kang SL, Jung YI. Sintering kinetics at final stage sintering: Model calculation and map construction. Acta Mater 2004, 52: 4573–4578.
Delannay F. The role of dihedral angle on the control of skeleton coordination and pore closure in aggregates driven by capillary forces. Scripta Mater 2010, 62: 928–933.
Kocjan A, Logar M, Shen ZJ. The agglomeration, coalescence and sliding of nanoparticles, leading to the rapid sintering of zirconia nanoceramics. Sci Rep 2017, 7: 2541.
Liu Y, Wu H, Chen GH. Enhanced mechanical properties of nanocomposites at low graphene content based on in situ ball milling. Polym Compos 2016, 37: 1190–1197.
Dong YH, Yang HB, Zhang L, et al. Ultra-uniform nanocrystalline materials via two-step sintering. Adv Funct Mater 2021, 31: 2007750.