Exploring influence of sintering temperature on the structure and technical characteristics of ATZ ceramic composites

• With a rise in alumina content, apparent density and volume shrinkage decrease, while apparent porosity, compressive strength, and Vickers hardness increase. • With a rise in sintering temperature, apparent porosity decreases, but apparent density, volume shrinkage, compressive strength, and Vickers hardness increase. • The spinel (Mg-Al 2 O 4 ) phase is formed after progressively sintering at 1400 or 1500 °C, however this reaction does not occur while sintering at 1600 °C. • Higher temperature sintered ceramics exhibit larger pores and a more homogeneous pore morphology. • With a rise in sintering temperature, both the size of the pore openings (the pore throat) and the number of these pore openings decrease. The current research intended to investigate the impact of sintering temperatures on the phase composition, pore morphology, physical and mechanical properties of porous ceramic composites. Porous zirconia-alumina-magnesia ceramic composites were successfully prepared using the starch consolidation casting and then sintered at three distinct temperatures (1400, 1500, and 1600 °C). Increasing sintering temperature reduce the apparent porosity (%) and increase the apparent density, volume shrinkage, hardness and compressive strength. With a rise in alumina content, apparent density and volume shrinkage decrease, while apparent porosity (%), hardness and compressive strength increase. The primary advantage of alumina is its capacity to enhance compressive strength by acting as a deterrent to fracture propagation. The XRD pattern illustrate that monoclinic zirconia is the main phase that is generated during sintering. Furthermore, at sintering temperatures of 1400 and 1500 °C, the spinel (Mg-Al 2 O 4 ) phase is produced by a reaction between the alumina and magnesia, but around 1600 °C, this reaction does not occur. In comparison to the microstructures sintered at 1400 °C or 1500 °C, porous ceramics sintered at 1600 °C exhibit larger pores and a more uniform pore morphology. The SEM results showed that when the sintering temperature rose from 1400 °C to 1600 °C, the ceramic grains grew, connection between the grains improved, and micro-voids among the grains diminished. To summarize, porous-structured ceramics sintered at 1600 °C are appropriate for use in porous bone replacement applications due to their high porosity (51–57 %), pore size (>100 μm), larger pore openings size, with better hardness and mechanical compressive strength. It may be suitable for use in cancellous bone replacement in regions such as the spine, pelvis, or cranial bones.