Preparation method of porous Al2O3 ceramic

Abstract

The invention relates to a preparation method of porous Al2O3 ceramic. The preparation method comprises the steps: adopting sintered-plate shaped alundum powder as raw material, adopting water glass solution as a binding agent, mixing the sintered-plate shaped alundum powder and the water glass solution into suspending liquid, fully stirring, injecting the obtained suspending liquid into a mold, freezing the suspending liquid in a vacuum freeze dryer, carrying out continuous drying thoroughly under vacuum state on the frozen suspending liquid, then demolding the sample, placing the demolded sample into a high-temperature box-type electric furnace, rising the temperature to 1500-1600 DEG C, keeping the temperature for 2 hours, and cooling naturally along the furnace to obtain the porous Al2O3 ceramic. As a vacuum freeze drying technique is adopted, the invention does not add any organic or inorganic chemical harmful substances, does not need special templates, and adopts ice as a hole-making template; and after the ice crystal is sublimated and removed, the ceramic particles obtain a porous microstructure of negative duplicates for growth of the ice crystal. The preparation method better inherits the ice crystal appearance, also does not need the processes of removing the templates, such as calcining, chemical etching and the like, not only has simple technique, but also has unique hole structure, and is easy to obtain a special hole structure.

Description

technical field [0001] The invention belongs to the field of material science, in particular to a porous Al 2 o 3 Methods of preparation of ceramics. Background technique [0002] Porous ceramics combine the excellent properties of pore structure and ceramics, not only have developed specific surface area, low density, low thermal conductivity and low heat capacity, but also have excellent high temperature resistance, wear resistance, weather resistance, corrosion resistance and good It can be used in heat insulation and sound insulation, molten metal filtration, catalyst carrier, automobile exhaust treatment, water purification and other aspects. At present, the application of porous ceramics has been expanded to high-end technical fields such as aviation, medicine and biochemistry. In addition, if different types of nanoparticles are assembled into the pores of porous ceramics, unique optical, magnetoelectric and other properties can appear, and new physical properties ...

AI Technical Summary

Problems solved by technology

Porous ceramics prepared by organic foam impregnation method, the pore size mainly depends on the pore size of the organic foam, the shape and density of the product are not easy to control, and the combustion of organic matter will pollute the environment; the porous ceramics prepared by adding pore-forming agents have poor pore distribution uniformity and are not It is suitable for the preparation of products with high porosity; the foaming method has high requirements for the selection of original components, and the process conditions are not easy to control; the sol-gel method is expensive due to the use of supercritical drying equipment, and the preparation cost is high; the chemical vapor infiltration or deposition method has strict process requirements , the pore shape is not easy to control, and the energy consumption is large; the biomimetic synthesis method mainly uses the natural porous tissue of the plant as a template, and makes porous ceramics through osmosis reaction, but the biological template needs to be removed, and the process is numerous and complicated, so it is not easy to popularize

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