3d Printing of Porous Glass Products Using the Robocasting Technique

3D printing of porous SiO2-Al2O3-Fe2O3-MgO-CaO-Na2O glass products with use of the robocasting technique was comprehensively studied. Features in the preparation of glass-based pastes with gelatin or agar for 3D printing were established and recommendations on the printing of porous glass products employing a ZMORPH 3D printer equipped with a thick paste extruder were developed. The method of preparing glass/gelatin and glass/agar pastes for 3D printing was tested experimentally. Mixtures with different contents of gelatin or agar, glass, and water were analyzed, and conditions for their storage from the time the paste components were mixed to the time they were loaded into the 3D printer were determined. The optimal 3D printing parameters were chosen with the Voxelizer software for the ZMORPH 3D printer with a thick paste extruder. A modification to the ceramic module for printing with pastes was proposed. The heat treatment process at 160 and 260 degrees C and sintering at 600-650 degrees C for the printed samples were studied. The temperature threshold at which a powdered glass material sintered without transiting to the molten state was found experimentally by choosing optimal temperatures and holding times. Heat treatment resulted in glass samples of complex shape. The samples reached 49% porosity. The mechanical properties and microstructure of the sintered porous glass samples were analyzed. The wear resistance and fracture of the samples were examined by repeated scratching with a conical diamond indenter.