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Ceramic foam filter technology exchange


Ceramic foam filter technology since the beginning of the 1970s, after 30 years of rapid development, the product range has a lot, such as: silicon carbide, zirconia, alumina, etc., are also filtered from the initial application of liquid aluminum to cast iron, bronze, steel and other fields (as shown in FIG. 1 is a heat riser gate Cup used to make ceramic foam filters and filter EPC). Currently in the domestic ceramic foam filters are mainly used in auto parts, diesel engine parts, compressors, wind power castings, castings and other high-end machine, and greatly improve the quality and competitiveness of our castings, while increasing the profits of the foundry business .

1. Filtering mechanism of ceramic foam filter

(1). Rectification. Turbulent liquid metal through the filter becomes smooth laminar flow state to avoid liquid metal coerced gas, reducing the liquid metal to the cavity erosion, slag play gating system function, to avoid secondary oxidation residue.

(2). Mechanical sieving. There are a lot of liquid metal oxide inclusions, slag and other impurities in chunks, by appropriate choice of pore ceramic foam filters can be sieved out a large number of inclusions.

(3). Mechanism of cake. Since the ceramic foam filter device having a three-dimensional structure, slag can be efficiently machinery, many larger than the filter pore size inclusions are trapped in the filter inlet. With the increase in the number of inclusions captured in the filter entrance formed by a large mixed composition of the "cake." The liquid flow thin filter cake, which is smaller than the filter pore size of inclusions is also partly captured in the "cake" on.

(4). Adsorption mechanism. Ceramic foam filter has a large surface area, is conducive to absorb large amount of fine particle inclusions, such adsorption mainly physical adsorption between molecules of gravity.

2. Ceramic foam filter performance requirements

(1). Filters should have good temperature strength, not the dregs during transport and operation;
(2). It has a certain high temperature strength, thermal shock resistance and resistance to liquid metal erosion capacity;
(3). Has good chemical stability, does not react with the liquid alloy;
(4). Having an appropriate pore size, good permeability alloy liquid filtration capacity and the ability to non-metallic inclusions; had good appearance quality: no distortion, small size deviation, and no uniform pore clogging phenomenon.

3. Economic application of ceramic foam filter

(1). Using filters can greatly reduce inclusions such defects;
(2). Grain refinement to improve the mechanical properties of the casting;
(3). Casting machinability improvement;
(4). Improve casting internal, external quality;
(5). Simplified gating system, improve casting yield;
(6). Reduce the allowance, to reduce repair costs.