[1]	G. Lu, G. Lu (Max) and Z. Xiao, Mechanical properties of porous materials, J. Porous Mat. 6 (1999) 359-368.
[2]	B. Seeber, U. Gonzenbach and L. Gauckler, Mechanical properties of highly porous alumina foams, J. Mater. Res. 28 (2013) 2281-2287. 
[3]	P. Wu, Y. Xu, Z. Huang and J. Zhang, A review of preparation techniques of porous ceramic membranes, J. Ceram. Process. Res. 16 (2015) 102-106.
[4]	T. Fukasawa, M. Ando, T. Ohji and S. Kanzaki, Synthesis of porous ceramics with complex pore structure by freeze-dry processing, J. Am. Ceram. Soc. 84 (2001) 230-232. 
[5]	D. Liu, Influence of porosity and pore size on the compressive strength of porous hydroxyapatite ceramic, Ceram. Int. 23 (1997) 135-139. 
[6]	P. Sepulveda, F. Ortega, M. Innocentini and V. Pandolfelli, Properties of highly porous hydroxyapatite obtained by the gelcasting of foams, J. Am. Ceram. Soc. 83 (2000) 3021-3024. 
[7]	Y.J. Park, B.W. Park, S.H. Lee, J.W. Lee, H.S. Yun and I.H. Song, The characterization of porous sintered reaction-bonded silicon nitride ceramics fabricated by Si-additive mixture granules, Int. J. Appl. Ceram. Tec. 8 (2011) 1501–1508.
[8]	B.D. Zdravkov, J.J. Cermak, M. Sefara and J. Janku, Pore classification in the characterization of porous materials: A perspective, Cent. Eur. J. Chem. 5 (2007) 385-395. 
[9] 	E.R. Hem, Silicon for silicon nitride based products, M.Sc. dissertation, Norwegian University of Science and Technology, Trondheim, 2014.
[10] 	S. Hampshire, Silicon nitride ceramics–review of structure, processing and properties, J. Achiev. Mater. Manuf. Eng. 24 (2007) 43-50.
[11]	D.V. Tuyen, Y.J. Park, H.D. Kim and B.T. Lee, Formation of rod-like Si3N4 grains in porous SRBSN bodies using 6Y2O3-2MgO sintering additives, Ceram. Int. 35 (2009) 2305-2310. 
[12]	J.F. Yang, Z.Y. Deng and T. Ohji, Fabrication and characterisation of porous silicon nitride ceramics using Yb2O3 as sintering additive, J. Eur. Ceram. Soc. 23 (2003) 371-378.
[13]	H.L. Hu, Y.P. Zeng, K.H. Zuo, Y.F. Xia, D.X. Yao, J. Günster, J.G. Heinrich and S.Li, Synthesis of porous Si3N4/SiC ceramics with rapid nitridation of silicon, J. Eur. Ceram. Soc. 35 (2015) 3781-3787.
[14] 	W. Guo, L. Wu, T. Ma, Y. You and H. Lin, Rapid fabrication of Si3N4 ceramics by reaction-bonding and pressureless sintering, J. Eur. Ceram. Soc. 36 (2016) 3919-3924. 
[15] 	J. Xu, D. Zhu, F. Luo, W. Zhou and P. Li, Dielectric properties of porous reaction-boned Si3N4 ceramics with controlled porosity and pore size, J. Mater. Sci. Technol. 24 (2009) 207-210. 
[16]	J. Xu, F. Luo, D. Zhu, X. Su and W. Zhou, Effect of presintering on the dielectric and mechanical properties of porous reaction-bonded silicon nitride, Mater. Sci. Eng. A 488 (2008) 167-171.
[17]	L. Yuan, J. Yu and S. Zhang, Effect of pore-forming agent on porous reaction-bonded silicon nitride ceramcis, IOP Conf. Ser.: Mater. Sci. Eng. 18 (2011) 1-4.
[18]	Y.J. Park and H.D. Kim, Permeability enhancement in porous-sintered reaction-bonded silicon nitrides, Int. J. Appl. Ceram. Tec. 8 (2011) 809-814.
[19]	A. Alem, M.D. Pugh and R.A.L. Drew, Open-cell reaction bonded silicon nitride foams: fabrication and characterization, J. Eur. Ceram. Soc. 34 (2014) 599-609.
[20]	H.M. Jennings and M.H. Richman, Structure. formation mechanisms and kinetics of reaction-bonded silicon nitride, J. Mater. Sci. 11 (1976) 2087-2098. 
[21]	A.J. Moulson, Reaction-bonded silicon nitride: its formation and properties, J. Mater. Sci. 14 (1979) 1017-1051.
[22]	H.M. Jennings, Review, On reactions between silicon and nitrogen, Part 1, Mechanisms, J. Mater. Sci. 18 (1983) 951-967.
[23]	A. Alem, R.A.L. Drew and M.D. Pugh, The influence of the nitriding parameters on the microstructure and strength of the open-cell reaction bonded silicon nitride foams fabricated via wet processing, J. Mater. Sci. 49 (2014) 4780-4789.
[24]	A. Alem, R.A.L. Drew and M.D. Pugh, The influence of α- and β-Si3N4 seeds on the on the properties of reaction bonded silicon nitride foams produced via wet processing, Ceram. Int. 40 (2014) 14287-14294.
[25]	A. Alem, M.D. Pugh and R.A.L. Drew, Reaction bonded silicon nitride foams: The influence of iron disilicide on microstructure and mechanical strength, Ceram. Int. 41 (2015) 4966-4974.  
[26]	C. Kawai and A. Yamakawa, Network formation of Si3N4 whiskers for the preparation of membrane filters, J. Mater. Sci. Lett. 17 (1998) 873-875. 
[27]	P. Becher, C. Hsueh, P. Angelini and T. Tiegs, Toughening behavior in whisker‐reinforced ceramic matrix composites, J. Am. Ceram. Soc. 71 (1988) 1050-1061.
[28]	P. Becher and G. Wei, Toughening behavior in SiC‐whisker‐reinforced alumina, J. Am. Ceram. Soc. 67 (1984) C267-C269.
[29]	O. Lukianova and O. Ivanov, The effect of Al2O3-MgO additives on the microstructure of spark plasma sintered silicon nitride, Ceram. Int. 44 (2018) 390-393. 
[30]	L. Bowen, T. Carruthers and R. Brook, Hot‐pressing of Si3N4 with Y2O3 and Li2O as additives, J. Am. Ceram. Soc. 61 (1978) 7-8. 
[31]	J. Almeida, A. Fonseca, R. Correia and J. Baptista, Pressureless sintering of silicon nitride with additives of the Y2O3-Al2O3-SiO2 system, Mater. Sci. Eng. A. 109 (1989) 395-400.
[32]	L. Cardenas, J. Lemus-Ruiz, D. Jaramillo-Vigueras and S. de la Torre, Spark plasma sintering of α-Si3N4 ceramics with Al2O3 and Y2O3 as additives and its morphology transformation, J. Alloy. Comp. 501 (2010) 345-351.
[33]	A. Alem, R.A.L. Drew and M.D. Pugh, Sintered reaction-bonded silicon nitride foams with a high level of interconnected porosity, J. Mater. Sci. 50 (2015) 570-576. 
[34]	A. Giachello, P.C. Martinengo, G. Tommasini and P. Propper, Sintering of silicon nitride in a powder bed, J. Mater. Sci. 14 (1979) 2825-2830.
[35]	S.H. Lee, G. Rixecker and F. Aldinger, Effects of powder bed conditions on the liquid-phase sintering of Si3N4, J. Mater. Res. 17 (2002) 465-472, 2002. 
[36]	F.L. Riley, Silicon nitride and related materials, J. Am. Ceram. Soc. 83 (2000) 245-265. 
[37]	B. Motavic, Low temperature sintering additives for silicon nitride, Ph.D. dissertation, Universität Stuttgart, Max-Planck-Institut für Metallforschung, Stuttgart, 2003. 
[38]	H. Lange, G. Wötting and G. Winter, Silicon nitride-From powder synthesis to ceramic materials, angewandte. chemie. 30 (1991) 1579-1597.
[39]	S. Yin, L. Pan, X. Fang, Y. Li , Y. Li , Y. Feng , T. Qiu and J. Yang, Porous Si3N4 ceramics prepared by aqueous gelcasting using low–toxicity DMAA system: Regulatable microstructure and properties by monomer content, Ceram. Int. 45 (2019) 9994-10003.
[40]	M. Mazzocchi and A. Bellosi, On the possibility of silicon nitride as a ceramic for structural orthopaedic implants. Part I: processing, microstructure, mechanical properties, cytotoxicity, J. Mater. Sci. Mater. Med. 19 (2008) 2881–2887. 
[41]	G. Ziegler, J. Heinrich and G. Wotting, Review, Relationships between processing, microstructure and properties of dense and reaction-bonded silicon nitride, J. Mater. Sci. 22 (1987) 3041-3086. 
[42]	M. Muller, J. Rogner, B. Okolo, W. Bauer and R. Knitter, Processing of micro-components made of sintered reaction-bonded silicon nitride (SRBSN). Part 2: Sintering behaviour and micro-mechanical properties, Ceram. Int. 36 (2010) 707-717. 
[43]	A. Barek, Sintering and post sintering of silicon nitride materials, Ph.D. dissertation, Lulea University of Technology, Lulea, 1992.
[44]	R.G. Pigeon, A. Varma and A.E. Miller, Some factors influencing the formation of reaction-bonded silicon nitride, J. Mater. Sci. 28 (1993) 1919-1936.
[45]	J.F. Yang, G.J. Zhang and T. Ohji, Fabrication of low-shrinkage, porous silicon nitride ceramics by addition of a small amount of carbon, J. Am. Ceram. Soc. 84 (2001) 1639-1641.
[46]	L. Li, J.W. Wang, H. Zhong, L.Y. Hao, H. Abadikhah, X. Xu, C.S. Chen and S. Agathopoulos, Novel α-Si3N4 planar nanowire superhydrophobic membrane prepared through in-situ nitridation of silicon for membrane distillation, J. Membr. Sci. 543 (2017) 98-105.
[47]	D. Yao, Y. Xia, K.H. Zuo, D. Jiang, J. Gunster, Y.P. Zeng and J.G. Heinrich, The effect of fabrication parameters on the mechanical properties of sintered reaction bonded porous Si3N4 ceramics, J. Eur. Ceram. Soc. 34 (2014) 3461-3467.
[48]	S.C. Danforth, H.M. Jennings and M.H. Richman, The influence of microstructure on the strength of reaction bonded silicon nitride (RBSN), Acta Metall. 27 (1979) 123-130.
[49]	N. Miyakawa, H. Sato, H. Maeno and H. Takahashi, Characteristics of reaction-bonded porous silicon nitride honeycomb for DPF substrate, JSAE Review. 24 (2003) 269-276.
[50]	B.S. Bal and M.N. Rahaman, Orthopedic applications of silicon nitride ceramics, Acta Biomaterialia. 8 (2012) 2889-2898.
[51]	B.T. Lee and H.D. Kim, Effect of sintering additives on the nitridation behavior of reaction-bonded silicon nitride, Mater. Sci. Eng. 364 (2004) 126-131. 
[52]	S.M. Boyer and A.J. Moulson, A mechanism for the nitridation of Fe-contaminated silicon, J. Mater. Sci. 13 (1978) 1637-1646.
[53]	M. Long , Y. Li, X. Jin, G. Yao, J. Sun and R.V.K. Kumar, Silicon nitridation mechanism in reaction-bonded Si3N4–SiC and Si3N4-bonded ferrosilicon nitride, J. Am. Ceram. Soc. 101 (2018) 4350-4356.
[54]	K. Sillapasa, S. Danchaivijit and K. Sujirote, Effects of silicon powder size on the processing of reaction-bonded silicon nitride, J. M. M. M. 15 (2005) 97-102. 
[55]	G. Yao, Y. Li, P. Jiang, X. Jin, M. Long, H. Qin and R.V. Kumar, Formation mechanisms of Si3N4 and Si2N2O in silicon powder nitridation, Solid State Sci. 66 (2017) 50-56. 
[56]	M.D. Pugh and A.J. Moulson, Vapour transport of magnesia into reaction-bonded silicon nitride, J. Mat. Sci. 30 (1995) 1425-1428. 
[57]	J.R.G. Evans and A.J. Moulson, The effect of impurities on the densification of reaction-bonded silicon nitride (RBSN), J. Mater. Sci. 18 (1983) 3721–3728. 
[58]	B.T. Lee, J.H. Yoo and H.D. Kim, Size effect of raw Si powder on microstructures and mechanical properties of RBSN and GPSed-RBSN bodies, Mater. Sci. Eng. A. 333 (2002) 306–313. 
[59]	F. Swinkels and M. Ashby, A second report on sintering diagrams, Acta Metallurgica. 29 (1981) 259-281.
[60]	R.M. German, P. Suri and S.J. Park, Review: liquid phase sintering, J. Mater. Sci. 44 (2009) 1–39.
[61]	X. Zhu and Y. Sakka, Textured silicon nitride: processing and anisotropic properties, Sci. Technol. Adv. Mater. 9 (2008) 1-47. 
[62]	K.P. Plucknett, M. Quinlan, L. Garrido and L. Genova, Microstructural development in porous β-Si3N4 ceramics prepared with low volume RE2O3-MgO-(CaO) additions (RE=La, Nd, Y, Yb), Mater. Sci. Eng. A. 489 (2008) 337-350.
[63]	S.I. Go, Y. Li, J.W. Ko, H.N. Kim, S.H. Kwon, H.D. Kim and Y.J. Park, Microstructure and thermal conductivity of sintered reaction-bonded silicon nitride: the particle size effects of MgO additive, Adv. Mater. Sci. Eng. 2018 (2018) 1-5. 
[64]	G. Ling and H. Yang, Pressureless sintering of silicon nitride with Magnesia and Yttria, Mater. Chem. Phys. 90 (2005) 31-34.
[65]	H. Liang, X. Yao, X. Liu and Z. Huang, The effect of powder bed on the liquid phase sintering of α-SiC, Mater. Des. 56 (2014) 1009-1013. 
[66]	J.R.G. Evans and A.J. Moulson, On the use of powder beds in the nitridation and subsequent densification of RBSN, J. Mater. Sci. Lett. 2 (1983) 236-238. 
[67]	J. Rouquerol, D. Avnir, D. Fairbridge, D.H. Everett, J.H. Haynes, N. Pernicone, J.D.F. Ramsay, K.S.W. Sing and K.K. Unger, Recommendations for the characterization of porous solids, Pure. & Appl. Chem. 66 (1994) 1739-1758.
[68]	W. Huo, X. Zhang, Y. Chen, Z. Hu, D. Wang and J. Yang, Ultralight and high-strength bulk alumina/zirconia composite ceramic foams through direct foaming method, Ceram. Int. 45 (2019) 1464–1467.
[69]	N. Michailidis, A. Tsouknidas, L. Lefebvre, T. Hipke and N. Kanetake, Production, charaterization, and applications of porous materials, Adv. Mater. Sci. Eng. 2015 (2014) 1-2. 
[70]	B. Bruckschen, H. Seitz, T.M. Buzug, C. Tille, B. Leukers and S. Irsen, Comparing different porosity measurement methods for characterization of 3D printed bone replacement scaffolds, Biomedizinische Technik. 50 (2005) 1609-1610.
[71]	J. Seuba, S. Deville, C. Guizard and A. Stevenson, Mechanical properties and failure behavior of unidirectional porous ceramics, Sci. Rep. 6 (2016) 1-11.
[72]	J. Yang, S. Shan, R. Janssen, G. Schneider, T. Ohji and S. Kanzaki, Synthesis of fibrous β-Si3N4 structured porous ceramics using carbothermal nitridation of silica, Acta Materialia, 53 (2005) 2981-2990. 
[73]	Z. Du, D. Yao, Y. Xia, K. Zuo, J. Yin, H. Liang and Y.P. Zeng, The high porosity silicon nitride foams prepared by the direct foaming method, Ceram. Int. 45 (2019) 2124-2130.
[74]	Y. Hu, Z. Xiao, H. Wang, C. Ye, Y. Wu and S. Xu, Fabrication and characterization of porous CaSiO3 ceramics, Ceram. Int. 45 (2019) 3710-3714.
[75]	C. Kawai and A. Yamakawa, Effect of porosity and microstructure on the strength of Si3N4: Designed microstructure for high strength, high thermal shock resistance, and facile machining, J. Am. Ceram. Soc. 10 (1997) 2705-2708.
[76]	X. Li, D. Yao, K. Zuo, Y. Xia, J. Yin, H. Liang and Y.P. Zeng, Fabrication, microstructural characterization and gas permeability behavior of porous silicon nitride ceramics with controllable pore structures, J. Eur. Ceram. Soc. 39 (2019) 2855-2861.  
[77]	F. Chen, Q. Shen, F. Yan and L. Zhang, Pressureless sintering of α‐Si3N4 porous ceramics using a H3PO4 pore‐forming agent, J. Am. Ceram. Soc. 90 (2007) 2379-2383. 
[78]	Y. Shao, D. Jia and B. Liu, Characterization of porous silicon nitride ceramics by pressureless sintering using fly ash cenosphere as a pore-forming agent, J. Eur. Ceram. Soc. 29 (2009) 1529-1534.
[79]	A. Kalemtas, G. Topates, H. Ozcoban, H. Mandal, F. Kara and R. Janssen, Mechanical characterization of highly porous β-Si3N4 ceramics fabricated via partial sintering & starch addition, J. Eur. Ceram. Soc. 33 (2013) 1507-1515.
[80]	Y. Lu, J. Yang, W. Lu, R. Liu, G. Qiao and C. Bao, Porous silicon nitride ceramics fabricated by carbothermal reduction-reaction bonding, Mater. Manuf. Process. 26 (2011) 855-861.
[81]	J.F. Yang, G.J. Zahng, N. Kondo, T. Ohji and S. Kanzaki, Synthesis of porous Si3N4 ceramics with rod-shaped pore structure, J. Am. Ceram. Soc. 88 (2005) 1030-1032.
[82]	J. Yu, J. Yang and H. Li, Pore structure control of Si3N4 ceramics based on particle-stabilized foams, J. Porous Mater. 19 (2012) 883-888.
[83]	J. Zhang, D. Jiang, Q. Lin, Z. Chen and Z. Huang, Properties of silicon carbide ceramics from gelcasting and pressureless sintering, Mater. Des. 65 (2015) 12-16. 
[84]	M. Kokabi, A. Pirooz and M. Nekoomanesh H., Gel-casting of engineering ceramics, Iran. Polym. J. 7 (1998) 169-175.
[85]	P. Tabrizian, F. Golestanifard, A. Alem and E. Ghasemmi, The influence of gel-casting parameters on the preparation of Si porous bodies, Mater. Lett. 183 (2016) 19-22. 
[86]	W. Zeng, X. Gan, Z. Li and K. Zhou, The preparation of silicon nitride ceramics by gelcasting and pressureless sintering, Ceram. Int. 42 (2016) 11593-11597.
[87] 	J. Tong and D. Chen, Preparation of alumina by aqueous gelcasting, Ceram. Int. 30 (2004) 2061-2966. 
[88] 	J. Ma, Z. Xie, H. Miao, B. Zhang, L. Xuping and Y. Cheng, Gelcasting of alumina ceramic components in nontoxic Na-alginate–CaIO3–PVP systems, Mater. Des. 26 (2005) 291-296. 
[89] 	T. Zhang, Z. Zhang, J. Zhang and Q.J.D. Lin, Preparation of dense SiC ceramics by aqueous gelcasting, J. Inorg. Mater. 41 (2007) 355-363. 
[90] 	X. Wang, Z. Xie, Y. Huang and Y. Cheng, Gelcasting of silicon carbide based on gelation of sodium alginate, Ceram. Int. 28 (2002) 865-871. 
[91] 	H. Shahbazi, H. Shokrollahi and A. Alhaji, Optimizing the gel-casting parameters in synthesis of MgAl2O4 spinel, J. Alloy. Compd. 712 (2017) 732-741. 
[92] 	L. Yuan, Z. Liu, X. Hou, Z. Liu, Q. Zhu, S. Wang, B. Ma and J. Yu, Fibrous ZrO2-mullite porous ceramics fabricated by a hydratable alumina based aqueous gel-casting process, Ceram. Int. 45 (2019) 8824-8831. 
[93] 	C. Zou, C. Zhang, B. Li, S. Wang and F. Cao, Microstructure and properties of porous silicon nitride ceramics prepared by gel-casting and gas pressure sintering, Mater. Des. 44 (2013) 114-118. 
[94] 	X. Guo, Gel casting of high strength ceramics, M.Sc. dissertation, Chalmers University of Technology, Goteborg, 2011.
[95]	A. Alem, A novel method to fabricate open-¬cell silicon nitride foams with a high and controlled level of porosity, Ph.D. dissertation, Concordia University, Montreal, 2014.
[96] 	J. Wu, X. Zhang and J. Yang, Novel porous Si3N4 ceramics prepared by aqueous gelcasting using Si3N4 poly-hollow microspheres as pore-forming agent, J. Eur. Ceram. Soc. 34 (2014) 1089-1096. 
[97]	L.J. Gibson and M.F. Ashby, Cellular solids, structure and properties, second ed., University of Cambridge, 1997. 
[98]	E. Guzi de Moraes, D. Li, P. Colombo and Z. Shen, Silicon nitride foams from emulsions sintered by rapid intense thermal radiation, J. Eur. Ceram. Soc. 35 (2015) 3263–3272.
[99]	K. Yamamoto and T. Sakai, Effect of pore structure on soot deposition in diesel particulate filter, Comput. 4 (2016) 1-11.
[100]	I. Sabree, J. E. Gough and B. Derby, Mechanical properties of porous ceramic scaffolds: Influence of internal dimensions, Ceram. Int. 41 (2015) 8425-8432.
[101]	K. Bodisova, M. Kasiarova, M. Domanicka, M. Hnatko, Z. Lences, Z. Varchulova Novakova, J. Vojtassak, S. Gromosova and P. Sajgalik, Porous silicon nitride ceramics designed for bone substitute applications, Ceram. Int. 39 (2013) 8355-8362. 
[102]	A. Jena and K. Gupta, Pore structure characterization of ceramic hot gas fiters, Ceram. Eng. Sci. Proc. 22 (2008) 1-8. 
[103]	J.F. Despois and A. Mortensen, Permeability of open-pore microcellular materials, Acta Mater. 53 (2005) 1381-1388.
[104]	T. Wan, D. Yao, J. Yin, Y. Xia, K. Zuo and Y. Zeng, The microstructure and mechanical properties of porous silicon nitride ceramics prepared via novel aqueous gelcasting, Int. J. Appl. Ceram. Tec. 12 (2015) 1-11.
[105]	J. Zhou, J.P. Fan, G.L. Sun, J.Y. Zhang, X.M. Liu, D.H. Zhang and H.J. Wang, Preparation and properties of porous silicon nitride ceramics with uniform spherical pores by improved pore-forming agent method, J. Alloy. Comp. 632 (2015) 655-660. 
[106]	L. Yin, X. Zhou, J. Yu and H. Wang, Highly porous silicon nitride foam prepared using a route similar to the making of aerated food, Int. J. Appl. Ceram. Tec. 13 (2015) 395‐404.
[107]	L. Yin, X. Zhou, J. Yu and H. Wang, Preparation of silicon nitride foam with three-dimensional interconnected pore structure, Mater. Design. 89 (2016) 620–625. 
[108]	L. Han, J. Wang, F. Li and H. Wang, Low-temperature preparation of Si3N4 whiskers bonded/reinforced SiC porous ceramics via foam-gelcasting combined with catalytic nitridation, J. Eur. Ceram. Soc. 38 (2018) 1210-1218. 
[109]	I.C. Jung, S.H. Cho, S.W. Na, J. Lee, H.S. Lee and W.S. Cho, Synthesis of Si3N4 whiskers in porous SiC bodies, Mater. Lett. 61 (2007) 4843-4846.
[110]	T. Imai, M. Mabuchi, Y. Tozawa and M. Yamada, Superplasticity in β-silicon nitride whisker-reinforced 2124 aluminium composite, J. Mater. Sci. Lett. 9 (1990) 255-257. 
[111]	J. Dusza, P. Sajgalik, Z. Bastl, V. Kavecansky and J. Durisin, Properties of β-silicon nitride whiskers, J. Mater. Sci. Lett. 11 (1992) 208-211. 
[112]	P. Sajgalik and J. Dusza, High-temperature strength and fracture toughness of Si3N4-β-Si3N4 composites, J. Mater. Sci. Lett. 10 (1991) 776-778. 
[113]	W.S. Park, D.J. Choi and H.D. Kim, Modification of inner pores with silicon carbide whiskers onto the Al2O3 substrate by CVI process, Key Eng. Mat. 287 (2005) 212-219. 
[114]	J.F. Yang, G.J. Zhang, N. Kondo and T. Ohji, Synthesis and properties of porous Si3N4/SiC nanocomposites by carbothermal reaction between Si3N4 and carbon, Acta Mater. 50 (2002) 4831-4840.
[115]	Y. Xu, S. Sang, Y. Li, L.L.Y. Zhao and L. Shujing, Pore structure, permeability, and alkali attack resistance of Al2O3-C refractories, Metall. Mater. Trans. A. 45 (2014) 2885-2893. 
[116]	M. Muller, W. Bauer and R. Knitter, Processing of micro-components made of sintered reaction-bonded silicon nitride (SRBSN). Part 1: Factors influencing the reaction-bonding process, Ceram. Int. 35 (2009) 2577-2585. 
[117]	C. Gazzara and D. Messier, Determination of phase content of Si3N4 by X-ray diffraction analysis, Am. Ceram. Soc. Bull. 56 (1977) 777-780.
[118]	X. Xi, H. Xiong, W. Guo, Q. Jiang, Y. Cheng and H.T. Lin, Effect of nitrogen pressure on preparation of β-Si3N4 whiskers, Ceram. Int. 43 (2017) 10610–10613. 
[119]	M.J. Wang and H. Wada, Synthesis and characterization of silicon nitride whiskers, J. Mater. Sci. 25 (1990) 1690-1698. 
[120]	C. Kawai and A. Yamakawa, Crystal growth of silicon nitride whiskers through a VLS mechanism using SiO2-Al2O3-Y2O3 oxides as liquid phase, Ceram. Int. 24 (1998) 135-138.
[121]	G.R. Terwilliger and F.F. Lange, Hot-pressing behavious of Si3N4, J. Am. Ceram. Soc. 57 (1974) 25-29.
[122]	G.W. Brindley and R. Hayami, Kinetics and mechanism of formation of forsterite (Mg2SiO4) by solid state reaction of MgO and SiO2, Philos. Mag. 12 (1965) 505-514. 
[123]	T. Sasamoto, H.L. Lee and T. Sata, Effects of porosity on vacuum-vaporization of magnesia, J. Ceram. Assoc. 82 (1974) 603-610. 
[124]	R.H. Lamoreaux and D.L. Hildenbrand, High-temperature vaporization behavior of oxides ll. Oxides of Be, Mg, Ca, Sr, Ba, B, Al, Ga, In, Ti, Si, Ge, Sn, Pb, Zn, Cd and Hg, J. Phys. Chem. Ref. Data. 16 (1987) 419-443.
[125]	J.L. de la Pena and M.I. Pech-Canul, Microstructure and kinetics of formation of Si2N2O and Si3N4 into Si porous preforms by chemical vapor infiltration (CVI), Ceram. Int. 33 (2007) 1349–1356.
[126]	P. Kroll and M. Milko, Theoretical investigation of the solid state reaction of silicon nitride and silicon dioxide forming silicon oxyniride under pressure, Z. Anorg. Allg. Chem. 629 (2003) 1737-1750.
[127]	B. Bill and H. Heping, The influence of different oxides on the formation of Si2N2O from SiO2 and Si3N4, J. Eur. Ceram. Soc. 6 (1990) 3-8. 
[128]	Z.K. Huang, P. Greil and G. Petzov, Formation of silicon oxinitride from Si3N4 and SiO2 in the presence of Al2O3, Ceram. Int. 10 (1984) 14-17. 
[129]	D. Yao, H. Chen, K.H. Zuo, Y. Xia, J. Yin, H. Liang and Y.P. Zeng, High temperature mechanical properties of porous Si3N4 prepared via SRBSN, Ceram. Int. 44 (2018) 11966-11971. 
[130]	Y. Zhou, H. Hyuga, D. Kusano, C. Matsunaga and K. Hirao, Effects of yttria and magnesia on densification and thermal conductivity of sintered reaction‐bonded silicon nitrides, J. Am. Ceram. Soc. 102 (2019) 1579-1588. 
[131]	W. Li, Y. Wu, R. Huang, S. Ye and H.T. Lin, Effect of Si addition on the mechanical and thermal properties of sintered reaction bonded silicon nitride, J. Eur. Ceram. Soc. 37 (2017) 4491-4496. 
[132]	J. Chen, N. Li, Y. Wei, B. Han, G. Li, W. Yan and Y. Zhang, Synthesis of Si3N4-SiC reaction-bonded SiC refractories: The effects of Si/C molar ratio on microstructure and properties, Ceram. Int. 43 (2017) 16518-16524. 
[133]	R. Nikonam M., M.D. Pugh and R.A.L. Drew, Formation mechanism of porous reaction-bonded silicon nitride with interconnected pores in the presence of MgO, J. Eur. Ceram. Soc. 39 (2019) 915-927. 
[134]	L.X. Wu, W.M. Guo, L.Y. Zeng and H.T. Lin, Equiaxed β–Si3N4 ceramics prepared by rapid reaction‐bonding and post‐sintering using TiO2–Y2O3–Al2O3 additives, J. Am. Ceram. Soc. 100 (2017) 5353-5357. 
[135]	C. Yu, J. Ding, C. Deng, H. Zhu and N. Peng, The effects of sintering temperature on the morphology and physical properties of in situ Si3N4 bonded MgO–C refractory, Ceram. Int. 44 (2018) 1104-1109. 
[136]	A.K. Garg and L.C. De Jonghe, Microencapsulation of silicon nitride particles with yttria and yttria-alumina precursors, J. Mater. Res. 5 (1990) 136-142. 
[137]	B. Bergman and H. Heping, The influence of different oxides on the formation of Si2N2O from SiO2 and Si3N4, J. Eur. Ceram. Soc. 6 (1990) 3-8. 
[138]	P.F. Becher, Multiple scale processes in microstructural evolution: case study of self-reinforced β-Si3N4, J. Korean Ceram. Soc. 53 (2016) 575-580.
[139]	M. Kramer, M.J. Hoffmann and G. Petzow, Grain growth studies of silicon nitride dispersed in an oxynitride glass, J. Am. Ceram. Soc. 76 (1993) 2778-2784. 
[140]	D.R. Clarke and G. Thomas, Grain boundary phases in a hot-pressed MgO fluxed silicon nitride, J. Am. Ceram. Soc. 60 (1977) 491-495. 
[141]	K. Mediaswanti, C. Wen, E.P. Ivanova, C.C. Berndt, F. Malherbe, V.T.H. Pham and J. Wang, A review on bioactive porous metallic biomaterials, J. Biomim. Biomater. Tissue Eng. 18 (2013) 1-8. 
[142]	M. Mitomo, Pressure sintering of Si3N4, J. Mater. Sci. 11 (1976) 1103-1107. 
[143]	F. Lange, Volatilization associcated with the sintering of polyphase Si3N4 materials, J. Am. Ceram. Soc. 65 (1982) 120-121. 
[144]	D. Li, B. Li, X. Yang, S. Gao and Y. Zheng, Fabrication and properties of in situ silicon nitride nanowires reinforced porous silicon nitride (SNNWs/SN) composites, J. Eur. Ceram. Soc. 38 (2018) 2671-2675.
[145]	Z. Du, D. Yao, Y. Xia, K. Zuo, J. Yin, H. Liang and Y.P. Zeng, The high porosity silicon nitride foams prepared by the direct foaming method, Ceram. Int. 45 (2019) 2124-2130.
[146]	G.P. Jiang and J.F. Yang, Extrusion of highly porous silicon nitride ceramics with bimodal pore structure and improved gas permeability, J. Am. Ceram. Soc. 101 (2018) 520-524.
[147]	J. Zhao, C. Yang, S. Shimai, X. Guan, G. Zhou, J. Zhang, J. Liu and S. Wang, The effect of wet foam stability on the microstructure and strength of porous ceramics, Ceram. Int. 44 (2018) 269-274.
[148]	X. Zhang, W. Huo, Y. Lu, K. Gan, S. Yan, J. Liu and J. Yang J, Porous Si3N4-based ceramics with uniform pore structure originated from single-shell hollow microspheres, J. Mater. Sci. 54 (2019) 4484-4494.
[149]	S. Van Bael, Y.C. Chai, S. Truscello, M. Moesen, G. Kerckhofs, H. Van Oosterwyck, J.P. Kruth and J. Schrooten, The effect of pore geometry on the in vitro biological behavior of human periosteum-derived cells seeded on selective laser-melted Ti6Al4V bone scaffolds, Acta Biomater. 8 (2012) 2824-2834.
[150]	M.C. Anderson and R. Olsen, Bone ingrowth into porous silicon nitride, J. Biomed. Mater. Res. A. 92 (2010) 1598-1605.
[151]	A.C. Jones, C.H. Arns, D.W. Hutmacher, B.K. Milthorpe, A.P. Sheppard and M.A. Knackstedt, The correlation of pore morphology, interconnectivity and physical properties of 3D ceramic scaffolds with bone ingrowth, Biomaterials 30 (2009) 1440-1451.
[152]	T. Konegger, L. Williams and R. Bordia, Planar, polysilazane‐derived porous ceramic supports for membrane and catalysis applications, J. Am. Ceram. Soc. 98 (2015) 3047-3053.
[153]	H.S. Lee, J.G. Kim and D.J. Choi, The effects of SiC whiskers and an SiC film coating deposited by chemical vapor infiltration (CVI) on a porous cordierite substrate, J. Mater. Sci. 43 (2008) 5574-5578.
[154]	L. Li, J.W. Wang, H. Zhong, L.Y. Hao, H. Abadikhah, X. Xu, C.S. Chen and S. Agathopoulos, Novel α-Si3N4 planar nanowire superhydrophobic membrane prepared through in-situ nitridation of silicon for membrane distillation, J. Membrane Sci. 543 (2017) 98-105. 
[155]	A. Mattern, B. Huchler, D. Staudenecker, R. Oberacker, A. Nagel and M. Hoffmann, Preparation of interpenetrating ceramic–metal composites, J. Eur. Ceram. Soc. 24 (2002) 3399-3408.
[156]	J. Binner, H. Chang and R. Higginson, Processing of ceramic-metal interpenetrating composites, J. Eur. Ceram. Soc. 29 (2009) 837-842.
[157]	F. Ye, J. Zhang, L. Liu and H. Zhan, Effect of solid content on pore structure and mechanical properties of porous silicon nitride ceramics produced by freeze casting, Mater. Sci. Eng. A. 528 (2011) 1421–1424.
[158]	T. Isobe, Y. Kameshima, A. Nakajima, K. Okada and Y. Hotta, Gas permeability and mechanical properties of porous alumina ceramics with unidirectionally aligned pores, J. Eur. Ceram. Soc. 27 (2007) 53-59, 2007.
[159]	B. Li, P. Jiang, M.W. Yan, Y. Li, X.M. Hou and J.H. Chen, Characterization and properties of rapid fabrication of netwrok porous Si3N4 ceramics, J. Alloy Compd. 709 (2017) 717-723.
[160]	R. Nikonam M., M.D. Pugh and R.A.L. Drew, Microstructural evolution mechanism of porous reaction bonded silicon nitride ceramics heat-treated in two powder beds, Ceram. Int. 45 (2019) 21986-21997. 
[161]	J. Zhou and C.A. Wang, Porous yttria-stabilized zirconia ceramics fabricated by nanoaqueous-based gelcasting process with PMMA microsphere as pore-forming agent, J. Am. Ceram. Soc. 96 (2013) 266-271.
[162]	R. Liu and C.A. Wang, Effects of mono-dispersed PMMA micro-balls as pore-forming agent on the properties of porous YSZ ceramics, J. Eur. Ceram. Soc. 3 (2013) 1859-1865.
[163]	S. Wang, Z. Yang, X. Duan, D. Jia, W. Cui, B. Sun and Y. Zhou, Effects of pore size on microstructure, mechanical and dielectric properties of gel casting BN/Si3N4 ceramics with spherical-shaped pore structures, J. Alloy Compd. 581 (2013) 46-51.
[164]	J. Bin, W. Zejun and Z. Naiqin, Effect of pore size and relative density on the mechanical properties of open cell aluminum foams, Scripta. Mater. 56 (2007) 169-172.
[165]	T.Y. Mays, A new classification of pore sizes, Stud. Surf. Sci. Catal. 160 (2007) 57-62.
[166]	M. Saladino, T. Motaung, A.S.A. Luyt, G. Nasillo and E. Caponetti, The effect of silica nanoparticles on the morphology, mechanical properties and thermal degradation kinetics of PMMA, Polym. Degrad. Stabil. 97 (2012) 452-459.
[167]	A.J. Wang, Y.P. Lu, R.F. Zhu, S.T. Li, G.Y. Xiao, G.F. Zhao and W.H. Xu, Effect of sintering on porosity, phase, and surface morphology of spray dried hydroxyapatite microspheres, J. Biomed. Mater. Res. A. 87 (2008) 557-562.
[168]	H. Giesche, Mercury porosimetry: a general (practival) overview, Part. Part. Syst. Char. 23 (2006) 1-11.
[169]	A. Jena and K. Gupta, Characterization of pore structure of filteration media, Fluid/Part. Sep. J. 14 (2002) 1-36,
[170]	Z. Luo, H. Liang, C. Qin, J. Zhang, T. Liu and A. Lu, Sintering behavior, microstructures and mechanical properties of porous CaO-Al2O3-SiO2-Si3N4 glass-ceramics, J. Alloy. Comp. 773 (2019) 71-77.
[171]	M. Precnerova, K. Bodisova, F. Frajkorova, D. Galuskova, Z. V. Novakova, J. Vojtassak, Z. Lences and P. Sajgalik, In vitro bioactivity of silicon nitride–hydroxyapatite composites, Ceram. Int. 41 (2015) 8100-8108.
[172]	X. Yang, B. Li, C. Zhang, S. Wang, K. Liu and C. Zou, Fabrication and properties of porous silicon nitride wave-transparent ceramics via gel-casting and pressureless sintering, Mater. Sci. Eng. A. 663 (2016) 174-180.
[173]	F. Wang, J. Guo, K. Li, J. Sun, Y. Zeng and C. Ning, High strength polymer/silicon nitride composites for dental restorations, Dent. Mater. 35 (2019) 1254-1263.
[174]	G. Pia, L. Casnedi and U. Sanna, Porous ceramic materials by pore-forming agent method: An intermingled fractal units analysis and procedure to predict thermal conductivity, Ceram. Int. 41 (2015) 6350-6357.
[175]	J.F. Yang, G.J. Zahng, N. Kondo, T. Ohji and S. Kanzaki, Synthesis of porous Si3N4 ceramics with rod-shaped pore structure, J. Am. Ceram. Soc. 88 (2005) 1030-1032.
[176]	R. Nikonam M., M.D. Pugh and R.A.L. Drew, Pore structure, porosity and compressive strength of highly porous reaction bonded silicon nitride ceramics with various grain morphologies, J. Mater. Sci. 55 (2020) 509-523. 
[177]	F. Porz and F. Thummler, Oxidation mechanism of porous silicon nitride, J. Mater. Sci. 19 (1984) 1283-1295.
[178]	J. Yang, J.F. Yang, S.Y. Shan, J.Q. Gao and T. Ohji, Effect of sintering additives on microstructure and mechanical properties of porous silicon nitride ceramics, J. Am. Ceram. Soc. 89 (2006) 3843-3845.
[179]	Y.F. Kargin, A.S. Lysenkov, S.N. Ivicheva, V.V. Zakorzhevskii, I.P. Borovinskaya, S.V. Kutsev and K.A. Solntsev, Hot-pressed Si3N4 ceramics containing CaO–Al2O3–AlN modifying additives, Inorg. Mater. 48 (2012) 1158-1163.
[180]	H. Yue, X. Wang and J. Tian, Formation of Si3N4 reticulated porous ceramics reinforced by needle-like β-Si3N4, Ceram. Int. 40 (2014) 8525-8532.
[181]	V.A. Hackley, U. Paik, B.H. Kim and S.G. Malghan, Aqueous processing of sintered reaction-bonded silicon nitride: I, dispersion properties of silicon powder, J. Am. Ceram. Soc. 80 (1997) 1781-1788.
[182]	P. Silva and J.L. Figueiredo, Production of SiC and Si3N4 whiskers in C+SiO2 solid mixtures, Mater. Chem. Phys. 72 (2001) 326-331.
[183]	H. Wang, Q. Zhang, H. Yang and H. Sun, Synthesis and microwave dielectric properties of CaSiO3 nanopowder by the sol-gel process, Ceram. Int. 34 (2008) 1405-1408.
[184]	G.J. Talwar, C. Joshi, S. Moharil, S. Dhopte, P. Muthal and V. Kondawar, A new precipitation based method for preparation of metasilicate phosphors, J. Alloy Compd. 35 (2011) 8742-8747.
[185]	X. Liu, M. Morra, A. Carpic and B. Li, Bioactive calcium silicate ceramics and coatings, Biomed. Pharmacother. 62 (2008) 526-529.
[186]	N. Karakus and H. Ozkan Toplan, Synthesizing Si3N4 from a mixture of SiO2-CaO, Mater. Tech. 48 (2014) 171-173.
[187]	S. Ni, J. Chang, L. Chou and W. Zhai, Comparison of osteoblast-like cell responses to calcium silicate and tricalcium phosphate ceramics in vitro, J. Biomed. Mater. Res. B 80 (2007) 174-183.
[188]	C.M. Wang, X. Pan, M. Rühle, F.L. Riley and M. Mitomo, Review: Silicon nitride crystal structure and observations of lattice defects, J. Mater. Sci. 31 (1996) 5281-5298.
[189]	R. Satet and M. Hoffmann, Grain growth anisotropy of β-silicon nitride in rare-earth doped oxynitride glasses, J. Eur. Ceram. Soc. 24 (2004) 3437-3445.
[190]	P. Sajgalik, J. Dusza and M.J. Hoffmann, Relationship between microstructure, toughening mechanisms, and fracture toughness of reinforced silicon nitride ceramics, J. Am. Ceram. Soc. 78 (1995) 2619-2624.
[191]	M. Mitorno, Microstructural development during gas-pressure sintering of α-silicon nitride, J. Am. Ceram. Soc. 75 (1992) 103-108.
[192]	H. Dean Batha and E. Dow Whitney, Kinetics and mechanism of the thermal decomposition of Si3N4, J. Am. Ceram. Soc. 56 (1973) 365-369.
[193]	C. Chen, X. Liang, M. Luo, S. Zhou, J. Ji, Z. Huang and M. Xu, Preparation and characterization of porous Si3N4-bonded SiC ceramics and morphology change mechanism of Si3N4 whiskers, Ceram. Int. 45 (2019) 5922-5926.
[194]	S. Xiao, H. Mei, D. Han, W. Yuan and L. Cheng, Porous (SiCw-Si3N4w)/(Si3N4-SiC) composite with enhanced mechanical performance fabricated by 3D printing, Ceram. Inte. 44 (2018) 14122-14127.
[195]	M.D. Pugh and L. Gavoret, Nitridation of whisker-reinforced reaction bonded silicon nitride ceramics, J. Mater. Sci. 35 (2000) 3257-3262.