Conclusion First!!!

Silicon Carbide Ceramic Foam Filter delivers outstanding filtration performance for molten copper!

The feedback information from our Thailand client who is testing our filter!

Silicon carbide ceramic foam filter achieves excellent purification effect on molten copper and copper alloys, and it is the preferred filter media for copper casting production.

Why SiC filter works so well for molten copper?

1. Superb high-temperature & chemical compatibility:

Copper melting temperature reaches around 1100–1200°C. SiC ceramic foam maintains stable physical and chemical properties under this temperature. It will not be corroded, softened or react with molten copper, avoiding contamination of copper liquid. In contrast, many other ceramic filters may suffer surface erosion when contacting copper melt.

2. Compound filtration mechanism for copper melt impurities:

It combines mechanical interception, deep adsorption and flow rectification:

  ● Traps large slag, oxide skin and refractory debris;

  ● Adsorbs fine Cu₂O inclusions and tiny non-metallic particles suspended in molten copper;

  ● Converts turbulent copper flow into smooth laminar flow, reducing secondary oxidation and gas entrapment during pouring.

3. Remarkable casting quality improvement:

It removes most oxide inclusions in copper liquid, effectively eliminating slag holes, porosity and oxide defects in copper castings. The finished copper castings gain better density, higher conductivity and superior mechanical properties. The rejection rate of copper castings can be greatly reduced.

4. Strong thermal shock resistance:

The SiC skeleton can endure sudden thermal shock from direct pouring of high-temperature copper liquid without cracking or shedding filter debris, preventing secondary pollution to molten copper.

5. Recommended PPI grades for copper casting:

  ● 10 PPI / 8 PPI: For large copper castings, high flow demand

  ● 20 PPI: General copper alloy castings, balanced flow & filtration precision

  ● 30 PPI: Precision thin-wall copper castings, ultra-fine inclusion removal

Raw Material of SiC filter!

Silicon Carbide Ceramic Foam Filter is a high-performance porous ceramic filter media, with high-purity silicon carbide (SiC) as the primary raw material, compounded with high-temperature inorganic binders, sintering aids and functional additives.

Its chemical composition is strictly controlled: SiC ≥62%, Al₂O₃ ≤28%, SiO₂ ≤10%, Fe₂O₃ ≤0.5%. The material features outstanding high-temperature stability, superior thermal conductivity, low thermal expansion coefficient and strong chemical inertness. It resists erosion by molten iron, copper alloy and high-temperature slag, and withstands continuous working temperature up to 1500°C.

The filter has an interconnected three-dimensional open-cell sponge skeleton, open porosity reaches 80%–90%, bulk density 0.3–0.5 g/cm³, and room-temperature compressive strength ≥1.0 MPa. Unlike alumina foam filters, SiC material delivers far better thermal shock resistance, surviving repeated rapid heating and cooling cycles without cracking under direct impact of hot molten metal.

Manufacturing Process

We adopt the mature polymer sponge replica method, the mainstream industrial process for reticulated ceramic foam:

1. Raw material batching & slurry mixing:

High-purity SiC powder and additives are fully blended with water to form homogeneous, stable ceramic slurry with controlled viscosity.

2. Polyurethane foam template impregnation:

The open-cell PU sponge is soaked in ceramic slurry, so the foam skeleton is evenly coated with ceramic slurry.

3. Squeezing & excess slurry removal:

Roller extrusion squeezes redundant slurry out, ensuring uniform coating thickness and unblocked pore channels.

4. Low-temperature drying:

Slow drying at controlled temperature to remove moisture and prevent green body cracking.

5. Template burnout & high-temperature sintering:

Heat treatment burns out the PU sponge template completely; sintering at around 1450–1500°C forms rigid, integrated SiC ceramic network structure.

6. Cutting, dimension calibration, full inspection and packaging:

Cut into standard or custom sizes, test pore uniformity, strength and appearance, then pack for shipment.

Pore grades are available in 8 PPI,10 PPI,20 PPI,30 PPI for different casting demands. Square, round, rectangular and custom shapes can be produced according to customer gating system drawings.

Our Advantages!!!

✅Stable raw material formula & consistent quality:

Independent formula development, strict incoming raw material inspection. Each batch undergoes lab tests for thermal shock resistance, compressive strength and pore uniformity to avoid filter breakage or shedding during pouring.

✅Full-size customisation capability:

We supply standard dimensions and tailor-made shapes, thicknesses and PPI grades to match customers’ gating design, low MOQ available for trial orders.

✅Professional metallurgical technical support:

Our foundry filtration team can help customers select the correct PPI grade, filter placement and installation suggestion based on alloy type, pouring temperature and casting weight.

✅Strict batch traceability & full pre-shipment inspection:

Every lot is inspected dimensionally and visually; quality reports can be provided upon request.

✅Reliable export packaging & fast delivery:

Anti-shock export cartons and pallet packaging to prevent damage in sea/land freight. Stable production capacity supports bulk orders and on-time shipment.

✅Competitive pricing for bulk supply:

As integrated manufacturer & exporter, we cut intermediate costs, offer cost-effective filtration consumables for long-term foundry cooperation.