The invention discloses high-linear light
transmittance fine crystalline transparent
alumina ceramics and a method for making the same under the condition of a
pulse electric field. The transparent
alumina ceramics is sintered within a temperature range of between 1,050 and 1,400 DEG C with the time of the entire
sintering process less than 30 minutes; moreover, the material has a
relative density higher than 99.5 percent, average grain size of between 0.3 and 1 micron, Vickers
hardness more than 20GPa, bending strength of between 700 and 900 MPa,
fracture toughness of between 3 and 4 MPam<1 / 2> and linear light
transmittance more than 50 percent; and the linear light
transmittance of a better material can reach to more than 62 percent. The transparent
alumina ceramics can be pure alumina with the purity more than 99.99 percent, or can be alumina ceramics in which one sort, or any two sorts, or any three sorts of addition agents including 0.01 to 0.5 percent of MgO, 0.01 to 0.5 percent of Y2O3, 0.01 to 0.5 percent of La2O3 and 0.01 to 0.5 percent of ZrO2 are added. The method for making the transparent alumina ceramics has the characteristics of low temperature and quickness; moreover, the technology has high reliability, and the deviation between the
mechanical property and the optical performance of transparent alumina made in different batches is not more than 2 percent.