Effect of Sintering Temperature on the Densification of Al2O3

Alumina powder compacts sintered at various temperatures were isostatically hot-pressed. The specimens sintered to the closed-pore state can be densified further by hot isostatic pressing. If the open pores are eliminated during sintering, sintering at a low temperature is desirable to achieve a full densification after hot-pressing. Sintering at high temperatures causes pores to be trapped inside the grains; these pores are difficult to eliminate by subsequent hot-pressing.