Inkjet printing and nanoindentation of porous alumina multilayers

The objectives of this study were to analyse the effect of inkjet 3-D printing parameters, particularly the splat overlap distance, for the fabrication of defect-free porous Al2O3 ceramic multilayers, and to correlate the resulting porosities with the mechanical properties measured using nanoindentation. An aqua based alumina ink was used in this study to fabricate the multilayers on dense alumina substrates by inkjet printing. The as-printed specimens were dried and sintered at 1200-1500 degrees C. The resulting microstructural features of each specimen and their corresponding porosities were studied using FIB-SEM. Elastic modulus and hardness were determined using the spherical nanoindentation technique. Results showed that defect-free porous alumina multilayers with excellent layer to layer and layer to substrate integrity were successfully fabricated. The porosity-dependence of the elastic modulus and hardness was shown to be consistent with values predicted using empirical expressions, despite the presence of abnormal grain growth at higher temperatures. (C) 2016 The Authors. Published by Elsevier Ltd.