Fused Silica is an amorphous silica material produced by electrically fusing high-purity silica and rapidly cooling the melt to prevent crystallization.
Due to its extremely low thermal expansion, excellent thermal shock resistance, and high refractoriness, fused silica is widely used in investment casting, refractory linings, foundry applications, and electronic industries.
Fused Silica is classified into different grades based on chemical purity and impurity control, among which A Grade and B Grade are the most commonly used industrial grades.
The table below compares the chemical composition of Fused Silica A Grade and B Grade:
| Component | Fused Silica A Grade | Fused Silica B Grade |
|---|---|---|
| SiO₂ | 99.9% min | 99.8% min |
| Fe₂O₃ | ≤ 100 ppm | ≤ 200 ppm |
| Al₂O₃ | ≤ 200 ppm | ≤ 200 ppm |
| Na₂O | ≤ 100 ppm | ≤ 200 ppm |
| K₂O | ≤ 100 ppm | ≤ 100 ppm |
| MgO | ≤ 200 ppm | ≤ 200 ppm |
| CaO | ≤ 100 ppm | ≤ 100 ppm |
| Magnetic Impurities | ≤ 50 ppm | ≤ 100 ppm |
This controlled impurity level ensures stable performance under high-temperature and thermal cycling conditions.
Both Fused Silica A and B Grade share similar physical characteristics due to their amorphous glass structure:
| Property | Value |
|---|---|
| Bulk Density | 2.18 – 2.20 g/cm³ |
| pH Value | ~6 |
| Melting Temperature | 1750°C |
| Softening Temperature | 1650°C |
| Linear Thermal Expansion (20–700°C) | 5 × 10⁻⁷ /°C |
| Thermal Behavior | Extremely low thermal expansion, excellent thermal shock resistance |
Key Advantage: The extremely low thermal expansion coefficient (5 × 10⁻⁷ /°C) makes fused silica ideal for rapid heating and cooling environments where dimensional stability is critical.
Fused silica is supplied as grains and powders, suitable for casting sands, flours, ramming masses, and refractory formulations.
| Phase | Content |
|---|---|
| Amorphous Glass | > 99% |
| Cristobalite / Crystalline Phase | < 1% |
The high amorphous content ensures near-zero expansion behavior and long service life at elevated temperatures.
1000 kg / 1250 kg
25 kg bags
25 kg bags on pallets
Export-standard packaging is available for global shipment.
Contact our technical team for detailed specifications, custom particle sizes, or material samples.