The influence of water bath temperature on the co-precipitated MgAl2O4 precursors and transparent ceramics

Water bath temperature plays a critical role in regulating the crystallization and growth kinetics during the co-precipitation process. In this work, MgAl 2 O 4 precursors were synthesized via co-precipitation route under gradient water bath temperatures, and the resulting transparent MgAl 2 O 4 ceramics were fabricated by hot isostatic pressing (HIP). The results indicate that lower water bath temperatures promote the formation of low-crystallinity granular precursors, whereas higher temperatures facilitate crystal growth and lead to rod-like precursors with higher crystallinity. The morphology of the calcined powders closely reflected that of the corresponding precursors. The HIP process eliminated the vast majority of pores, producing transparent ceramics. Subsequent annealing in air further improved the transmittance. Notably, the sample prepared at 30 °C exhibited high transmittance in the visible region and low defect density.