Ceramics-Silikáty

High-performance 95 wt.% alumina structural ceramics are key materials for mechanical seals, semiconductor equipment and new energy components. However, their industrial production still faces challenges such as high sintering temperature, large batch-to-batch performance fluctuations and low yield. In this study, the integrated preparation process including powder pretreatment, composite forming and multi-stage gradient sintering was systematically optimized through orthogonal experiments, and the effects of process parameters on phase composition, microstructure and mechanical properties were revealed. The results show that the optimized process achieves low-temperature densification sintering at 1580 °C, and the prepared ceramics have a relative density of 99.6±0.1%, bending strength of 485±12 MPa, fracture toughness of 5.2±0.3 MPa·m ^0.5 and Vickers hardness of 18.2±0.4 GPa, with comprehensive mechanical properties improved by more than 22%. In pilot-scale industrial production, the batch yield increased from 82.3% to 96.7%, the single-piece production cycle was shortened by 31.2%, and the relative standard deviation of flexural strength between batches decreased from 8.7% to 2.1%. This study provides a scientific basis for the stable and efficient industrial production of high-performance alumina structural ceramics.