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

A technology of alumina ceramics and light transmittance, applied in the field of preparation of transparent ceramic materials, can solve the problems of difficult repeatability, long sample prefabrication stage, high cost, and achieve the effect of high reliability

Inactive Publication Date: 2008-11-19
王昕
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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 pressi

Method used

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

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0027] Al with a purity of 99.99% and an average particle size of 300nm 2 o 3 The powder is loaded directly into graphite moulds. Control the furnace temperature to rise to 600°C within 3 minutes, then heat to 1150°C for 5 minutes and keep at this temperature for 5 minutes. During the sintering process, keep the pressure at 80MPa, then cut off the power supply and cool down. When the furnace temperature drops to 200°C, take out the graphite mold as a sample . Then, without high-temperature oxidation treatment, the ceramic sheet was directly polished on both sides to a thickness of 0.8 mm to test the optical properties.

[0028] The relative density of the sintered ceramic sample is 99.7%, the average grain size is 0.5 micron, and the linear light transmittance of the material is 56.7% when the wavelength is 640nm. The Vickers hardness of the material is 21.3GPa, the bending strength is 770MPa, and the fracture toughness is 3.2MPam 1 / 2 . The transparent ceramic sheet is as...

Embodiment 2

[0030] Taking alumina as 100%, weigh MgO with a mass percentage of 0.02%, and then Al with a purity of 99.99% and an average particle size of 400nm 2 o 3 The powder was put into a ball mill jar and milled with water and high-purity alumina balls as the medium for 1 hour, and the pH value was adjusted to 3 with 0.1M nitric acid solution before ball milling. After ball milling, vacuum-dry at 80°C for 4 hours and pass through a 60-mesh sieve. Dry press the sieved powder with a steel mold at 50 MPa, and then press at 200 MPa to obtain a green body. Then put the biscuit into the graphite mold, control the furnace temperature to rise to 600°C within 3 minutes, then heat it to 1280°C for 6 minutes and keep it at this temperature for 7 minutes. During the sintering process, keep the pressure at 50 MPa, then cut off the power supply to cool, and the furnace temperature drops When the temperature reaches 200°C, take out the graphite mold as a sample. Afterwards, it was treated under ...

Embodiment 3

[0033] Taking alumina as 100%, weigh 0.3% of Y by mass 2 o 3 , and then with the quotient Al with a purity of 99.99% and an average particle size of 300nm 2 o 3 The powder was put into a ball mill jar and milled with water and high-purity alumina balls as the medium for 1 hour, and the pH value was adjusted to 3 with 0.1M nitric acid solution before ball milling. After ball milling, vacuum-dry at 80°C for 4 hours and pass through a 60-mesh sieve. Dry press the sieved powder with a steel mold at 50 MPa, and then press at 200 MPa to obtain a green body. Then put the biscuit into the graphite mold, control the furnace temperature to rise to 600°C within 3 minutes, then heat it to 1200°C for 6 minutes and keep it at this temperature for 10 minutes, keep the pressure at 50MPa during the sintering process, then cut off the power supply to cool, and the furnace temperature drops When the temperature reaches 200°C, take out the graphite mold as a sample. Afterwards, it was treate...

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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...

Claims

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Application Information

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IPC IPC(8): C04B35/10C04B35/622
Inventor 赵喆王昕
Owner 王昕
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