Cold sintering is an innovative low-temperature processing technique which allows consolidation of several ceramics. Despite recent research activities on the cold sintering of functional and structural ceramics, an analytical study accounting for consolidation and grain growth phenomena is still missing in the literature. In this work, we provide a theoretical analysis of the mechanisms active during cold sintering. The analysis considers two cold sintering approaches, characterised by the application either of isostatic or uniaxial pressure. Physical phenomena and microstructural features are discussed in view of the applied cold sintering approach. The developed pressure-assisted densification models indicate that the processes governing densification during uniaxial cold sintering are more complex than those of conventional liquid phase sintering. A key role is played by the water/material interaction which promotes several effects such as formation of surface defects and secondary phases, dynamic recrystallization and other phenomena still partially unknown.
GuoJ, GuoH, BakerAL, Cold sintering: A Paradigm Shift for processing and integration of ceramics. Angew Chemie – Int Ed. 2016;55:11457–11461. doi:10.1002/anie.201605443.
2.
RandallCA, GuoJ, BakerA, Cold sintering ceramics and composites, US20170088471A1, 2017.
3.
MariaJ, KangX, FloydRD, Cold sintering: current status and prospects. J Mater Res. 2017;32:3205–3218. doi:10.1557/jmr.2017.262.
4.
GuoJ, BerbanoSS, GuoH, Cold sintering process of composites: bridging the processing temperature gap of ceramic and polymer materials. Adv Funct Mater. 2016;26:7115–7121. doi:10.1002/adfm.201602489.
5.
FunahashiS, GuoH, GuoJ, Cold sintering and co-firing of a multilayer device with thermoelectric materials. J Am Ceram Soc. 2017;100:3488–3496. doi:10.1111/jace.14852.
6.
FunahashiS, GuoJ, GuoH, Demonstration of the cold sintering process study for the densification and grain growth of ZnO ceramics. J Am Ceram Soc. 2017;100:546–553. doi:10.1111/jace.14617.
7.
Gonzalez-JulianJ, NeuhausK, BernemannM, Unveiling the mechanisms of cold sintering of ZnO at 250°C by varying applied stress and characterizing grain boundaries by Kelvin probe force microscopy. Acta Mater. 2018;144:116–128. doi:10.1016/j.actamat.2017.10.055.
8.
LiuJA, LiCH, ShanJJ, Preparation of high-density InGaZnO4target by the assistance of cold sintering. Mater Sci Semicond Process. 2018;84:17–23. doi:10.1016/j.mssp.2018.04.030.
9.
JingY, LuoN, WuS, Remarkably improved electrical conductivity of ZnO ceramics by cold sintering and post-heat-treatment. Ceram Int. 2018;44:20570–20574. doi:10.1016/j.ceramint.2018.07.192.
10.
MedriV, ServadeiF, BendoniR, Journal of the European ceramic society nano-to-macroporous TiO2 (anatase) by cold sintering process. J Eur Ceram Soc. 2019;39:2453–2462. doi:10.1016/j.jeurceramsoc.2019.02.047.
11.
BouvilleF, StudartAR.Geologically-inspired strong bulk ceramics made with water at room temperature. Nat Commun. 2017;8; doi:10.1038/ncomms14655.
12.
LengH, HuangJ, NieJ, Cold sintering and ionic conductivities of Na3.256Mg0.128Zr1.872Si2PO12solid electrolytes. J Power Sources. 2018;391:170–179. doi:10.1016/j.jpowsour.2018.04.067.
13.
CharoonsukT, SukkhaU, KolodiazhnyiT, Enhancing the densification of ceria ceramic at low temperature via the cold sintering assisted two-step sintering process. Ceram Int. 2018;44:S54–S57. doi:10.1016/j.ceramint.2018.08.253.
14.
GuoH, GuoJ, BakerA, Hydrothermal-Assisted cold sintering process: a new guidance for low-temperature ceramic sintering. ACS Appl Mater Interfaces. 2016;8:20909–20915. doi:10.1021/acsami.6b07481.
15.
WangD, GuoH, MorandiCS, Cold sintering and electrical characterization of lead zirconate titanate piezoelectric ceramics. APL Mater. 2018;6:16101. doi:10.1063/1.5004420.
16.
MaJP, ChenXM, OuyangWQ, Microstructure, dielectric, and energy storage properties of BaTiO3ceramics prepared via cold sintering. Ceram Int. 2018;44:4436–4441. doi:10.1016/j.ceramint.2017.12.044.
17.
NdayishimiyeA, LargeteauA, PrakasamM, Low temperature hydrothermal sintering process for the quasi-complete densification of nanometric α -quartz. Scr Mater. 2018;145:118–121. doi:10.1016/j.scriptamat.2017.10.023.
18.
GuoH, BakerA, GuoJ, Cold sintering process: a novel technique for Low-temperature ceramic processing of ferroelectrics. J Am Ceram Soc. 2016;99:3489–3507. doi:10.1111/jace.14554.
19.
SeoJH, GuoJ, GuoH, Cold sintering of a Li-ion cathode: LiFePO4-composite with high volumetric capacity. Ceram Int. 2017;43:15370–15374. doi:10.1016/j.ceramint.2017.08.077.
20.
BerbanoSS, GuoJ, GuoH, Cold sintering process of Li1.5Al0.5Ge1.5(PO4)3 solid electrolyte. J Am Ceram Soc. 2017;100:2123–2135. doi:10.1111/jace.14727.
21.
LiuY, SunQ, WangD, Development of the cold sintering process and its application in solid-state lithium batteries. J Power Sources. 2018;393:193–203. doi:10.1016/j.jpowsour.2018.05.015.
22.
NdayishimiyeA, BufS, DourgesM, Scripta materialia design of 0–3 type nanocomposites using hydrothermal sintering. Scr Mater. 2018;148:15–19. doi:10.1016/j.scriptamat.2018.01.013.
23.
IndujaIJ, SebastianMT.Microwave dielectric properties of mineral sillimanite obtained by conventional and cold sintering process. J Eur Ceram Soc. 2017;37:2143–2147. doi:10.1016/j.jeurceramsoc.2017.01.007.
24.
IndujaIJ, SebastianMT.Microwave dielectric properties of cold sintered Al2O3–NaCl composite. Mater Lett. 2018;211:55–57. doi:10.1016/j.matlet.2017.09.083.
25.
Bin HongW, LiL, CaoM.Plastic deformation and effects of water in room-temperature cold sintering of NaCl microwave dielectric ceramics. J Am Ceramic Soc. 2018;101:4038–4043. doi:10.1111/jace.15572.
GuoH, GuoJ, BakerA, Cold sintering process for ZrO2-based ceramics: significantly enhanced densification evolution in yttria-doped ZrO2. J Am Ceram Soc. 2017;100:491–495. doi:10.1111/jace.14593.
28.
JiangA, KeD, XuL, Cold hydrostatic sintering: from shaping to 3D printing. J Mater. 2019;5:496–501.IN PRESS.
29.
RahamanMN.Ceramic processing and sintering. New York (NY): Marcel Dekker; 1996.
30.
ChiangY-M, BirnieD, KingeryPWD.Physical ceramics: principles for ceramic science and engineering. New York, USA: Wiley; 1997.
31.
MilleroJ.The apparent and partial molal volume of aqueous sodium chloride solutions at various temperatures. J Phys Chem. 1970;74:356–362. doi: 10.1021/j100697a022
32.
TrevaniLN, BalodisEC, TremainePR.Apparent and standard partial molar volumes of NaCl, NaOH, and HCl in water and heavy water at T = 523 and 573 K at p = 14 MPa. J Phys Chem B2007;111:2015–2024. doi:10.1021/jp063824x.
33.
WilleyJD.The effect of pressure on the solubility of minerals in Seawater at 0°C. Mar Chem1974;2:239–250. doi: 10.1016/0304-4203(74)90018-8
34.
SawamuraS, EgoshiN, SetoguchiY, Solubility of sodium chloride in water under high pressure. Fluid Phase Equilib. 2007;254:158–162. doi:10.1016/j.fluid.2007.03.003.
35.
CambonO, HainesJ.Hydrothermal Crystal growth of piezoelectric α-quartz phase of AO2 (A = Ge, Si) and MXO4 (M = Al, Ga, Fe and P = P, As): A Historical Overview. Crystals (Basel). 2017;7:38 doi:10.3390/cryst7020038.
KwonO-H, MessingGL.A theoretical analysis of solution-precipitation controlled densification during liquid phase sintering. Acta Metall. 1991;39:2059–2068. doi: 10.1016/0956-7151(91)90176-2
40.
KingeryWD.Densification during sintering in the presence of a liquid phase. I. Theory. J Appl Phys. 1959;30:301–306. doi:10.1063/1.1735155.
41.
KingeryWD, WoulbrounJM, CharvatFR.Effects of applied pressure on densification during sintering in the presence of a liquid phase. J Am Ceram Soc. 1963;46:391–395. doi: 10.1111/j.1151-2916.1963.tb11758.x
42.
ColombaniJ.Measurement of the pure dissolution rate constant of a mineral in water. Geochim Cosmochim Acta. 2008;72:5634–5640. doi:10.1016/j.gca.2008.09.007.
43.
FrostP, WernerF, DelgadoA.The viscosity of water at high pressures – especially at subzero degrees centigrade. Rheol Acta. 2000;39:566–573. doi:10.1007/s003970000114.
44.
TraskineV, SkvortsovaZ, MuralevA.Intergranular pressure solution in internally wetted polycrystals : effect of additives. Mater Sci Eng A. 2008;495:132–137. doi:10.1016/j.msea.2007.09.088.
SchenkO, UraiJL.Microstructural evolution and grain boundary structure during static recrystallization in synthetic polycrystals of sodium chloride containing saturated brine. Contrib Mineral Petrol. 2004;146:671–682. doi:10.1007/s00410-003-0522-6.
47.
HosoiK, KawaiS, YanagisawaK, Densification process for spherical glass powders with the same particle size by hydrothermal hot pressing. J Mater Sci. 1991;26:6448–6452. doi:10.1007/BF02387828.
48.
DoremusRH.Glass Science, II, 1994.
49.
LiW, OlevskyEA, MckittrickJ, Densification mechanisms of spark plasma sintering : multi-step pressure dilatometry. J Mater Sci. 2012;47:7036–7046. doi:10.1007/s10853-012-6515-y.
50.
GiuntiniD, OlevskyEA.Sintering stress of nonlinear viscous materials. J Am Ceram Soc. 2016;99:3520–3524. doi:10.1111/jace.14550.
