Inkjet printing yttria stabilized zirconia coatings on porous and nonporous substrates

Abstract

This article describes the development of Yttria stabilized Zirconia coatings on porous and non-porous substrates through inkjet printing process and explores the role of substrate in defining coating characteristics through micro structural characterization and micro indentation. Zirconia based inks were prepared through high energy ball milling and printed on porous and non porous substrates. The low temperature sintering of coated substrates lead to stabilization of metastable t-phase of Zirconia, thus ensuring durability of coatings. However, the open pore sites in non porous substrate is incapable of retaining the fine particles in the ink on the substrate as they seep through the open pores. But, the combination of coarse and fine particles in ink resulted in controlling permeability of initial layers of coatings consequently forming thin coatings over porous substrates. Micro indentation tests on inkjet printed coatings on porous substrates and non porous substrate confirmed the capability of inkjet printing process to develop uniformly thick ceramic coatings irrespective of the type of substrate. Furthermore, it was revealed that multiple bi-layer coatings with coarse and fine PSD material powder based inks result in higher hardness in comparison to fine PSD material based inks.