Porous TiO2 ceramics with lamellar architecture were fabricated by the freeze casting technique. As the initial solid loading increased from 40 to 80 wt-%, the porosity decreased from 68 to 16% correspondingly. Their compression properties improved with the deduction in the porosity. A sudden change in compressive strength was found when the porosity decreased from 60 to 45% due to evolution of the lamellar microstructure. The failure mechanisms during indentation tests were investigated and discussed with regards to their microstructures.
SepulvedaP, BinnerJGP: ‘Processing of cellular ceramics by foaming and in situ polymerisation of organic monomers’, J. Eur. Ceram. Soc., 1999, 19, 2059–2066.
2.
StudartAR, GonzenbachUT, TervoortE, GaucklerLJ: ‘Processing routes to macroporous ceramics: a review’, J. Am. Ceram. Soc., 2006, 89, 1771–1789.
3.
BurgKJL, PorterS, KellamJF: ‘Biomaterial developments for bone tissue engineering’, Biomaterials, 2000, 21, 2347–2359.
4.
RamayHR, ZhangMQ: ‘Preparation of porous hydroxyapatite scaffolds by combination of the gel-casting and polymer sponge methods’, Biomaterials, 2003, 24, 3293–3302.
5.
SofieSW, DoganF: ‘Freeze casting of aqueous alumina slurries with glycerol’, J. Am. Ceram. Soc., 2001, 84, 1459–1464.
6.
DevilleS, SaizE, NallaRK, TomsiaAP: ‘Freezing as a path to build complex composites’, Science, 2006, 311, 515–518.
7.
DevilleS: ‘Freeze-casting of porous ceramics: a review of current achievements and issues’, Adv. Eng. Mater., 2008, 10, 155–169.
8.
DevilleS, SaizE, TomsiaAP: ‘Freeze casting of hydroxyapatite scaffolds for bone tissue engineering’, Biomaterials, 2006, 27, 5480–5489.
DevilleS: ‘Freeze-casting of porous biomaterials: structures, properties and opportunities’, Materials, 2010, 3, 1943–1927.
11.
WegstUGK, SchecterM, DoniusAE, HungerPM: ‘Biomaterials by freeze casting’, Philos. Trans. R. Soc. London A, 2010, 368A, 2099–2121.
12.
FuQ, RahamanMN, DoganF, BalBS: ‘Freeze casting of porous hydroxyapatite scaffolds. I. Processing and general microstructure’, J. Biomed. Mater. Res. B, 2008, 86B, 125–135.
DaiL: ‘Aligned carbon nanotubes for multifunctional nanocomposites and nanodevices: from plastic optoelectronics to bioceramics’, Adv. Appl. Ceram., 2008, 107, 177–189.
15.
JokinenM, PatsiM, RahialaH, PeltolaT, RitalaM, RosenholmJB: ‘Influence of sol and surface properties on in vitro bioactivity of sol–gel-derived TiO2 and TiO2–SiO2 films deposited by dip-coating method’, J. Biomed. Mater. Res., 1998, 42, 295–302.
16.
MaJF, WangSQ, DuRX, LiXD: ‘Pressureless sintering of gelcast ZTA–MgO–TiO2 systems as potential dental ceramics’, Adv. Appl. Ceram., 2011, 110, 275–279.
17.
NygrenH, TengvallP, LundstromI: ‘The initial reactions of TiO2 with blood’, J. Biomed. Mater. Res., 1997, 34, 487–492.
18.
TiainenH, LyngstadaasSP, EllingsenJE, HaugenHJ: ‘Ultra-porous titanium oxide scaffold with high compressive strength’, J. Mater. Sci., Mater. Med., 2010, 21, 2783–2792.
19.
RenL, ZengY.-P, JiangD: ‘Fabrication of gradient pore TiO2 sheets by a novel freeze-tape-casting process’, J. Am. Ceram. Soc., 2007, 90, 3001–3004.
20.
RenL, ZengY.-P, JiangD: ‘Preparation of porous TiO(2) by a novel freeze casting’, Ceram. Int., 2009, 35, 1267–1270.
21.
LiuG, ZhangD, MeggsC, ButtonTW: ‘Porous Al2O3–ZrO2 composites fabricated by an ice template method’, Scr. Mater., 2010, 62, 466–468.
22.
OliverWC, PharrGM: ‘An improved technique for determining hardness and elastic modulus using load and displacement sensing indentation experiments’, J. Mater. Res., 1992, 7, 1564–1583.
23.
ZhangHF, HussainI, BrustM, ButlerMF, RannardSP, CooperAI: ‘Aligned two- and three-dimensional structures by directional freezing of polymers and nanoparticles’, Nat. Mater., 2005, 4, 787–793.
24.
ButlerMF: ‘Instability formation and directional dendritic growth of ice studied by optical interferometry’, Cryst. Growth Des., 2001, 1, 213–223.
25.
KorberC, RauG, CosmanMD, CravalhoEG: ‘Interaction of particles and a moving ice–liquid interface’, J. Cryst. Growth, 1985, 72, 649–662.
26.
LiuG, ZhangD, ButtonTW: ‘Preparation of concentrated barium titanate suspensions incorporating nano-sized powders’, J. Eur. Ceram. Soc., 2010, 30, 171–176.
27.
ZhangD, SuB, ButtonTW: ‘Preparation of concentrated aqueous alumina suspensions for soft-molding microfabrication’, J. Eur. Ceram. Soc., 2004, 24, 231–237.
28.
GibsonLJ, AshbyMF: ‘Cellular solids structure and properties’, In Cambridge University Press 2nd edn. 1997 Cambridge, UK: Cambridge University Press.
29.
LiuDM: ‘Influence of porosity and pore size on the compressive strength of porous hydroxyapatite ceramic’, Ceram. Int., 1997, 23, 135–139.
30.
BullSJ: ‘Nanoindentation of coatings’, J. Phys. D, 2005, 38D, R393–R413.
31.
VecchioneN, WasmerK, BalintDS, NikbinK: ‘Characterization of EB-PVD yttrium-stabilised zirconia by nanoindentation’, Surf. Coat. Technol., 2009, 203, 1743–1747.
