Preparation method of calcium hexaluminate foamed ceramic with multilayer structure

Abstract

The invention discloses a preparation method of a calcium hexaluminate foamed ceramic with a multilayer structure. The preparation method comprises the following steps: completely immersing a pretreated polyurethane sponge template in slurry I, extruding redundant slurry by rolling, then carrying out high-pressure blast or centrifugal slurry throwing, and drying at 100-120 DEG C for 16-24 hours; then putting the mixture into a muffle furnace at 700-900 DEG C, keeping the temperature for 2-4 hours, and naturally cooling; and completely immersing a calcium hexaluminate foamed ceramic preform in the slurry II, keeping for 3-7 minutes under a vacuum condition, carrying out high-pressure air blowing or centrifugal slurry throwing and natural drying to obtain a calcium hexaluminate foamed ceramic green body, drying for 16-24 hours at 100-120 DEG C, then putting the green body into a high-temperature furnace, carrying out heat preservation for 2-5 hours at 1500-1600 DEG C, and then cooling along with the furnace to obtain the calcium hexaluminate foamed ceramic with the multilayer structure. Through detection, the normal-temperature compressive strength of the prepared microporous multilayer structure calcium hexaluminate foamed ceramic is 3.0-8.0 MPa, the number of times of water cooling circulation is 12-20; and the anti-erosion and anti-scouring capability is excellent.

Description

technical field [0001] The invention belongs to the technical field of materials, and in particular relates to a preparation method of calcium hexaaluminate foam ceramics with a multilayer structure. Background technique [0002] Since the 1970s, foamed ceramics have attracted widespread attention due to their high specific surface area and porosity, good high temperature performance, chemical stability and filtration and adsorption, and they are widely used in metallurgy, chemical industry, environmental protection, light industry And other fields, achieved good economic and social benefits. The traditional preparation methods of foam ceramics include: foaming method, sol-gel method, adding pore-forming agent method and organic foam impregnation method, etc. Among them, the organic foam impregnation method is an effective process for preparing high-porosity foam ceramics. The porous ceramics prepared by this method have an open-pore three-dimensional network skeleton struc...

AI Technical Summary

Problems solved by technology

The main defects of this method are: (1) the cost of raw materials used is high; (2) the sintering temperature is high, and the sintering shrinkage is large, which is not conducive to energy saving and environmental protection and the yield is low; (3) zirconia is prone to crystal transformation with temperature changes, Accompanied by a large volume change, resulting in cracking of the product during firing

This method improves the mechanical properties of the product to a certain extent, but has the following disadvantages: (1) The cost of raw materials is high; (2) The polyurethane foam is hanged by pressing 5 to 10 times, which fails to ensure the hang of the polyurethane foam. The slurry is uniform and the slurry is sufficient; (3) The hollow pore structure produced by the in-situ decomposition of the polyurethane sponge after sintering is not processed, and it is easy to form stress concentration under the action of external stress, resulting in damage to the foam ceramics; (4) The process is complex, And high energy consumption, not suitable for mass production