Corrosion of Silicon Carbide Kiln Furniture in Gas-Fired Sintering Furnaces

Corrosion of Silicon Carbide Kiln Furniture in Gas-Fired Sintering Furnaces: A Complex Process

The corrosion of silicon carbide kiln furniture in gas-fired sintering furnaces is a complex process influenced by multiple factors, including gas composition, sintering temperature, furnace atmosphere, and the intrinsic properties of the silicon carbide material itself.

### Key Factors Contributing to Silicon Carbide Corrosion in Gas-Fired Sintering Furnaces

1. Gas Composition:

Certain components in the fuel gas, particularly sulfur-containing compounds and chlorides, can chemically react with silicon carbide at high temperatures, leading to surface corrosion. These reactions may produce volatile substances that gradually erode the silicon carbide material.

2. Sintering Temperature:

Sintering temperature is a critical factor in silicon carbide corrosion. Excessively high temperatures accelerate chemical reactions between silicon carbide and gas components, intensifying corrosion. Therefore, sintering temperatures in gas-fired furnaces must be strictly controlled to prevent thermal damage to silicon carbide materials.

3. Furnace Atmosphere:

The composition and stability of the furnace atmosphere significantly impact silicon carbide corrosion. Excess oxygen or other oxidizing gases can exacerbate oxidative corrosion of silicon carbide. Additionally, humidity within the furnace must be considered, as water vapor at high temperatures may react with silicon carbide, promoting corrosion.

4. Material Properties of Silicon Carbide:

The purity, crystal structure, and microscopic defects of silicon carbide directly affect its corrosion resistance. High-purity silicon carbide generally exhibits superior resistance to corrosion, while materials with intact crystal structures and fewer microscopic defects demonstrate enhanced durability against degradation.

II. Impact of Silicon Carbide Kiln Furniture Corrosion on Product Quality

1. Product Quality Issues

- The corrosion of kiln furniture leads to surface irregularities, which may leave scratches or uneven impressions on the products, severely compromising their aesthetic quality.

- Dimensional and shape changes caused by corrosion can result in non-uniform temperature and pressure distribution during sintering. This may lead to defects such as cracks, porosity, or structural inhomogeneity in the final products.

- Impurities released during corrosion (e.g., metallic contaminants) may infiltrate the products, altering their chemical properties and degrading performance characteristics. This contamination can also compromise the intended functionality or application of the materials.

II. Impact on Production Efficiency

2. Reduced Production Efficiency

- Corrosion accelerates wear on kiln furniture, shortening its lifespan and requiring more frequent replacements. This increases downtime for production lines.

- Corrosion may trigger equipment malfunctions or operational instability, necessitating additional maintenance and adjustments, further reducing production efficiency.

III. Increased Production Costs

3. Increased maintenance and replacement of kiln furniture raise material and labor costs for manufacturers.

- Due to unstable product quality and reduced efficiency, manufacturers may need to invest more resources in rework, sorting, or quality control, increasing labor and quality assurance costs.

Conclusion

Carbonization of silicon carbide kiln furniture has significant impacts on product quality and production efficiency. Manufacturers must prioritize corrosion issues and implement effective measures to mitigate these effects, ensuring stable product quality and operational performance.

Recommended Mitigation Strategies

1. Optimize Fuel Gas Composition: Use low-sulfur and low-chloride gas to minimize chemical reactions with silicon carbide.

2. Precise Sintering Temperature Control: Maintain optimal sintering temperatures to avoid thermal degradation of silicon carbide materials.

3. Adjust Furnace Atmosphere: Stabilize furnace conditions by reducing oxidizing gases and humidity, slowing corrosion rates.

4. Select High-Quality Silicon Carbide Materials: Choose silicon carbide with high purity, intact crystal structures, and minimal microscopic defects to enhance corrosion resistance.

5. Regular Maintenance and Inspection: Periodically inspect gas-fired sintering furnaces to identify and address corrosion issues promptly, ensuring long-term durability of silicon carbide components.