The invention relates to a preparation method of an aluminum oxide sintered body. The preparation method includes the steps that aluminum oxide powder, deionized water and binder rho-aluminum oxide are evenly mixed and stirred and placed in a bag, stand still for 12-15 h in a sealed mode, and are placed in a die in a filled mode and subjected to pressure maintaining for 60-150 s at the pressure of 50-80 MPa, preformed cakes are subjected to vacuum sealed packaging and then placed on an isostatic cool pressing machine for isostatic cool pressing, finally, the cakes obtained after isostatic cool pressing are placed in a microwave sintering furnace for vacuum sintering, and then the aluminum oxide sintered body is obtained. The density of the sintered body is larger than 3.75 g/cm , and the purity of the sintered body is larger than 5 N. According to the method, the purity of powder can be effectively controlled, cost is low, industrial production is easy, and high practical application value is achieved.

Preparation method of aluminum oxide sintered body

A black alumina ceramic powder and processes for producing a black alumina ceramic body The powder comprises Al 2O 3; a pigment composed of Fe 2O 3, NiO, MnO 2 and Co 2O 3; and an additive selected from the group consisting of SiO 2, TiO 2 and La 2O 3 and combination thereof

A black alumina ceramic powder, a black alumina ceramic body made of it and a process for producing the black alumina ceramic body

The invention provides a preparation method of a high-temperature ultra-low sodium alumina powder material. Firstly, industrial aluminum hydroxide is subjected to a drying pretreatment; secondly, an appropriate amount of mineralizer and a seed crystal are added to the pretreated aluminum hydroxide for high-temperature roasting; thirdly, the high-temperature roasting product is subjected to washingwith dilute acid; finally, the washed alumina powder is ball-milled to a certain particle size, and the high-temperature ultra-low sodium alumina powder material is obtained. By adopting the method,the sodium oxide content of industrial alumina can be can effectively reduced, and the thermal shock resistance, electrical insulation, hardness and strength of the alumina powder material can be remarkably enhanced.

Preparation method of high-temperature ultra-low sodium alumina powder material

The invention discloses a black alumina ceramic, a preparation method thereof and an alumina ceramic device. The black alumina ceramic comprises components in percentage by mass as follows: 90%-95% of Al2O3, 2.5%-9% of a black toner and 1%-2.5% of a sintering aid. The heat expansion coefficient of the black alumina ceramic is close to that of a glass device, wettability for the black alumina ceramic and the glass device is improved, the difference of the heat expansion coefficients is reduced, the yield of sealing between the black alumina ceramic and a glass sealing piece in an application process is increased, and the black alumina ceramic has a uniform pure black color; according to the preparation method, the sintering temperature is low, the dimensional stability is realized, and the finished product ratio is high. The black alumina ceramic device is prepared from the black alumina ceramic.

Black alumina ceramic, manufacturing method thereof and alumina ceramic device

The utility model provides a preparation method of calcined alumina powder for black ceramics and relates to a preparation method of calcined alumina powder suitable fore preparing bright high alumina black ceramics. The preparation method of the calcined alumina powder is characterized by comprising the following preparation steps: mixing activated alumina with salt solution of black oxide in proportion, drying and adding an additive capable of refining a crystal grain and uniformly mixing, adding mixed power into a crucible and adding into a high-temperature furnace for calcining to obtain black calcined alumina; and grinding the black calcined alumina to obtain the calcined alumina powder for the black ceramics. Through the method, as the activated alumina is uniformly mixed with the salt solution of the black oxide, the reaction area is increased, and the reaction activity is increased. Meanwhile, the additive capable of refining the crystal grain is added and is calcined into black powder at a proper temperature, the alumina and the black oxide form discontinuous solid solution, and the discontinuous solid solution can stably exist in the ceramic sintering process and is uniformly colorated. The preparation method is high in sintering activity, is suitable for low-temperature sintering and is convenient to operate.

Jin Wang

Papers

Preparation method of calcined alumina powder for black ceramics