Ceramic samples with open porosity were manufactured from powders of various sizes and shapes. The porosity value varied within 20–50%, while the bending strength reached 130 MPa. The influence of the morphology of Al2O3 nanopowders on the structure and strength of porous ceramics made from them was studied, and the possibility of increasing the specific strength by filling open pores with epoxy resins was established. A method for obtaining composite materials with low specific gravity (2–2.5 g/cm3) was developed. The objective of the experiment was to obtain a composite in which each component would have a continuous structure. Samples of polymer-ceramic composites with an Al2O3 matrix were made, combining the advantages of both materials, which led to an increase in specific strength. The materials of the article were presented at the International Scientific and Practical Conference "Advanced Engineering Technologies AET 2022" held in St. Petersburg on November 21–25, 2022.