Templated Grain Growth in Macroporous Materials

TL;DR

This paper introduces a simple method combining ice templating and templated grain growth to produce macroporous, crystallographically textured ceramic materials with aligned grains and lamellar walls, applicable to alumina and sodium potassium niobate.

Contribution

It presents a novel, facile process for creating textured, macroporous ceramics with controlled grain orientation and morphology at multiple scales.

Findings

Achieved long-range crystallographic order in macroporous ceramics.

Developed a modified March-Dollase equation for texture characterization.

Demonstrated the method on alumina and sodium potassium niobate.

Abstract

We demonstrate a facile method to produce crystallographically textured, macroporous materials using a combination of modified ice templating and templated grain growth (TGG). The process is demonstrated on alumina and the lead-free piezoelectric material sodium potassium niobate. The method provides macroporous materials with aligned, lamellar ceramic walls which are made up of crystallographically aligned grains. Each method showed that the ceramic walls present a long-range order over the entire sample dimensions and have crystallographic texture as a result of the TGG process. We also present a modification of the March-Dollase equation to better characterize the overall texture of materials with textured but slightly misaligned walls. The controlled crystallographic and morphologic orientation at two different length scales demonstrated here can be the basis of multifunctional materials.