Fine-crystal transparent alumina ceramic of high straight-line luminous transmittance and method for preparing same

Abstract

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.

Description

technical field [0001] The invention relates to the preparation of transparent ceramic materials, in particular to a fine-grained transparent alumina ceramic with high linear light transmittance and its preparation method under the condition of the presence of a pulse electric field. Background technique [0002] Since the publication of the first transparent alumina ceramic patent US3026210, the application of transparent alumina ceramics in high-pressure sodium lamps has always been dominant. In order to improve the light transmittance of transparent alumina ceramics, most patents focus on the selection of additives, and MgO is the most widely used main additive. MgO and Y are used in the patent US3377176 2 o 3 Compound doping to improve light transmittance, while the patent EP134195 uses MgO and La 2 o 3 The composite doping, more patent CN86101452 uses MgO, Y 2 o 3 , La 2 o 3 and ZrO 2 quaternary doping system. No matter what kind of additives are used, all the...

AI Technical Summary

Problems solved by technology

However, these hot isostatic pressing processes require a relatively long sample prefabrication stage, including biscuit molding and low-temperature pre-firing, plus the final hot isostatic pressing treatment often takes at least 24 hours.

The complex process of the hot isostatic pressing process determines that the technology is difficult to repeat in actual operation, and the cost is high

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