Translucent Alumina Ceranmic Prepared by Two-Step Pressureless Sintering in a Hydrogen Gas Atmosphere

The translucent alumina ceramic with high density and fine grain size was fabricated by a two-step pressureless sintering process in a hydrogenolysis gas atmosphere. The results show that the first-step sintering temperature(T1) was 1 650-1 750 ℃ and the second-step sintering temperature(T2) was 1 600-1 650 ℃. The mechanical properties of the sample prepared by two-step pressureless sintering (T1=1 750 ℃, T2=1 650 ℃) were far more improvement than that of the sample prepared by one-step sintering, and its opitical properties met the general requirements of the lamp.