Editing Ceramic (section)

====Ice-templating for enhanced mechanical properties====
If a ceramic is subjected to substantial mechanical loading, it can undergo a process called [[Freeze-casting|ice-templating]], which allows some control of the [[microstructure]] of the ceramic product and therefore some control of the mechanical properties. Ceramic engineers use this technique to tune the mechanical properties to their desired application. Specifically, the [[Strength of materials|strength]] is increased when this technique is employed. Ice templating allows the creation of macroscopic pores in a unidirectional arrangement. The applications of this oxide strengthening technique are important for [[solid oxide fuel cell]]s and [[Water purification|water filtration]] devices.<ref>{{cite journal |last1=Martinić |first1=Frane |last2=Radica |first2=Gojmir |last3=Barbir |first3=Frano |title=Application and Analysis of Solid Oxide Fuel Cells in Ship Energy Systems |journal=Brodogradnja |date=31 December 2018 |volume=69 |issue=4 |pages=53–68 |doi=10.21278/brod69405 |s2cid=115752128 |doi-access=free |url=https://hrcak.srce.hr/file/306607 }}</ref>

To process a sample through ice templating, an aqueous [[Colloid|colloidal suspension]] is prepared to contain the dissolved ceramic powder evenly dispersed throughout the colloid,{{clarify|reason=is the powder in suspension or actually dissolved?|date=December 2019}} for example [[yttria-stabilized zirconia]] (YSZ). The solution is then cooled from the bottom to the top on a platform that allows for unidirectional cooling. This forces ice crystals to grow in compliance with the unidirectional cooling, and these ice crystals force the dissolved YSZ particles to the solidification front{{clarify|date=June 2023}} of the solid-liquid interphase boundary, resulting in pure ice crystals lined up unidirectionally alongside concentrated pockets of colloidal particles. The sample is then heated and at the same the pressure is reduced enough to force the ice crystals to [[Sublimation (phase transition)|sublime]] and the YSZ pockets begin to [[Annealing (metallurgy)|anneal]] together to form macroscopically aligned ceramic microstructures. The sample is then further [[Sintering|sintered]] to complete the [[evaporation]] of the residual water and the final consolidation of the ceramic microstructure.{{citation needed|date=December 2019}}

During ice-templating, a few variables can be controlled to influence the pore size and morphology of the microstructure. These important variables are the initial solids loading of the colloid, the cooling rate, the sintering temperature and duration, and the use of certain additives which can influence the microstructural morphology during the process. A good understanding of these parameters is essential to understanding the relationships between processing, microstructure, and mechanical properties of anisotropically porous materials.<ref>{{cite journal |last1=Seuba |first1=Jordi |last2=Deville |first2=Sylvain |last3=Guizard |first3=Christian |last4=Stevenson |first4=Adam J. |title=Mechanical properties and failure behavior of unidirectional porous ceramics |journal=Scientific Reports |date=14 April 2016 |volume=6 |issue=1 |pages=24326 |doi=10.1038/srep24326 |pmid=27075397 |pmc=4830974 |bibcode=2016NatSR...624326S }}</ref>