1.From the 1960s---1963, American scientist Schwartzwalder invented the organic foam impregnation method. Porous ceramics were obtained by impregnating ceramic slurry with organic foam skeleton and removing organics at high temperature, laying the core preparation principle for foam ceramics (containing alumina base), which is the technical source of alumina foam ceramic chips.
2.From the 1970s---1978, Mollard FR and Davidson N of the United States developed alumina ceramic foam filter that can be used for aluminum alloy casting filtration by using organic foam impregnation method with alumina and kaolin as the main raw materials, greatly improving the quality of castings and reducing the scrap rate, marking that aluminum oxide foam ceramic chips officially entered the industrial application stage and promoting their large-scale development.
3.In the 1980s---Europe, the United States, Japan and other countries competed in research and development to form foam ceramic filters of various materials and specifications. The production was promoted to mechanization and automation, and the products were serialized and standardized.
China started the research of alumina foam ceramics in the early 1980s. Harbin University of Technology, Shanghai Institute of Machinery Manufacturing Technology and other institutions took the lead in carrying out relevant work, gradually realizing technological autonomy and industrialization, and narrowing the gap with the international market.
The mainstream process is organic foam impregnation and the steps are as follows:
1.Slurry preparation: Mix alumina powder, binder, dispersant, sintering aid and water, stir to make a uniform slurry with high solid content and low viscosity.
2.Impregnation and slurry hanging: immerse the prefabricated organic foam framework (such as polyurethane sponge) into the slurry, and make the slurry adhere to the hole wall of the foam framework evenly through extrusion and rolling to remove the excess slurry.
3.Drying and curing: place the foam body after slurry hanging in the drying oven and dry it at 80 – 120 ℃ to solidify the adhesive, improve the strength of the body and prevent deformation in subsequent treatment.
4.Degreasing and glue discharging: put the dried green body into the sintering furnace and heat it at 400 – 600 ℃ to make the organic foam framework and binder completely decompose and volatilize to form porous alumina green body. At this stage, it is necessary to control the heating rate to prevent the green body from cracking.
5.High temperature sintering: the degreased green body is heated to 1400 – 1600 ℃ for sintering, so that the aluminum oxide particles undergo solid phase reaction, the grains grow up and closely combine, forming a high-strength ceramic skeleton, and finally obtaining aluminum oxide foam ceramic chips.
6.Post processing: Cut, polish, and clean according to requirements to obtain finished products with specified dimensions and precision.
1.High porosity: The porosity is generally between 60% and 90%, and the pore size can be adjusted (from tens of micrometers to a few millimeters), with interconnected pores.
2.Low density: The bulk density is only 0.3-1.2 g/cm ³, much lower than that of dense alumina ceramics (about 3.95 g/cm ³).
3.High temperature resistance: Long term use temperature can reach 1200-1600 ℃, short-term can withstand high temperature of 1800 ℃, without melting or softening.
4.Corrosion resistance: acid and alkali resistance (except for strong alkaline media), chemical solvent resistance, superior to metal porous materials.
5.Good filtration performance: The connected pore structure can efficiently intercept solid particles in the fluid with low fluid resistance.
6.Thermal insulation: High porosity hinders heat conduction and convection, making it an excellent high-temperature insulation material.
7.Moderate mechanical strength: The compressive strength and flexural strength meet the requirements of industrial use, and have a certain degree of toughness, which is not easily brittle.
8.Strong customizability: Different sizes, shapes and PPI can be customized and so it can meet the needs of different applications.
- High temperature filtration field
1.Metal melt filtration: When casting non-ferrous metals such as aluminum, copper, zinc, etc., it filters out oxide inclusions and impurity particles in the melt to improve the purity of the casting.
2.High temperature flue gas filtration: used for high-temperature flue gas dust removal in industries such as metallurgy, chemical engineering, and waste incineration, intercepting dust particles and purifying gases.
- Thermal insulation field
1.Industrial kiln lining: insulation layer for ceramic kilns, metallurgical furnaces, and glass kilns to reduce heat loss and save energy.
2.Aerospace components: As insulation materials for spacecraft and engines, they can withstand high temperature environments.
- Catalytic carrier field
1.Automotive exhaust treatment: Can be loaded with catalysts to replace some metal carriers, used for catalytic conversion of harmful substances in exhaust.
2.Chemical catalysis: As a catalyst carrier in chemical reactions, it increases the reaction contact area and improves catalytic efficiency.
- Other fields
1.Sound absorption and noise reduction: Used as sound-absorbing materials in high-temperature and corrosive environments, such as engine compartments and sound insulation layers in industrial plants.
2.Biomedicine: high-purity alumina foam ceramics can be used as bone tissue engineering scaffolds, with good biocompatibility.
Alinna Wang
Email: alinna@bestpacking.cn
Tel/WhatsApp: +86 17307992122
Wechat: karol1005
Post time: Jan-22-2026