Effect of plant waste materials as pore-forming agents on the preparation and characterization of macroporous cordierite–mullite–zirconia ceramic composites

Porous ceramic materials have generated significant attention and played pioneering roles in a variety of industries. This work aims to prepare porous ceramic composites based on cordierite, mullite, and tetragonal zirconia (t-ZrO₂), which are considered one of the most effective materials in several applications. Nanoparticles were synthesized using sol-gel and co-precipitation methods and then characterized using X-ray diffraction (XRD), transmission electron microscope (TEM), and surface area measurements. The tetragonal form of the prepared nano zirconia was stabilized using ceria. To prepare the cordierite-mullite-t-ZrO₂ macroporous ceramics, nano t-ZrO₂ was added in various ratios from 0 to 30 wt% at the expense of nano mullite, while nano cordierite was added at a 70 wt%. Plant waste materials (bagasse ash and sawdust ash) were recycled and used as pore-forming agents in the fabrication of porous ceramic materials at a constant amount of 10 wt% to increase porosity and reduce environmental pollution problems. The prepared samples were sintered at three different temperatures: 1375, 1400, and 1350 °C. The densification characteristics (bulk density and apparent porosity), cold crushing strength (CCS), phase composition, microstructure, pore size distribution, and contact angle of sintered porous ceramics were studied. The results showed that the bulk density, apparent porosity, and cold crushing strength ranged from 1.42 to 1.95 g/cm³, 46 to 56%, and 3.26 to 31.35 MPa, respectively.