Fused quartz crucibles, also called fused silica crucibles or high-purity quartz crucibles, are specialized containers made from amorphous silicon dioxide (SiO₂) engineered for ultra-clean melting and crystal growth at temperatures exceeding 1100°C. They provide a chemically inert, thermally stable vessel where contamination must be eliminated—critical in semiconductor wafer manufacturing, photovoltaic silicon ingot production, and high-purity materials research.
Key Features & Benefits
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High Purity SiO₂: Available in 99.9%–99.99% grades, minimizing metallic impurities and preventing melt contamination in sensitive applications.
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Superior Thermal Shock Resistance: Low coefficient of thermal expansion (approx. 0.54–0.6×10⁻⁶/°C) allows rapid heating/cooling cycles without cracking—even when a red-hot crucible is plunged into cold water.
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High Service Temperature: Continuous use up to 1100–1200°C; short-term exposure up to 1700°C depending on grade.
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Chemical Inertness: Excellent resistance to most acids (except hydrofluoric acid) and corrosive environments, making it ideal for demanding chemical and metallurgical processes.
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Dimensional Accuracy: Precise wall thickness and diameter tolerances ensure reproducible conditions for crystal growth and laboratory applications.
Applications & Common Sizes
Fused quartz crucibles serve critical roles across multiple high-tech industries:
Semiconductor Crystal Growth: Used in Czochralski (CZ) furnaces for growing monocrystalline silicon ingots from high-purity silicon feedstock. The crucible must withstand continuous heating above 1420°C, controlled cooling gradients, and long cycle times (10–50 hours per run).
Solar / Photovoltaic Industry: Essential for producing polysilicon ingots for solar cells. As standard solar cell sizes increase, manufacturers demand larger crucibles with enhanced durability and uniformity.
Laboratory & Research: Used for high-temperature chemical reactions, material synthesis, ash content determination, and precious metals melting (gold, silver).
Jewelry & Metallurgy: Ideal for melting precious metals and specialty alloys due to high purity and thermal shock resistance.
Technical Specifications
| Parameter | Value | Notes |
|---|---|---|
| Material | Fused Quartz (Fused Silica) | Amorphous SiO₂ |
| SiO₂ Purity | ≥99.9% (standard); 99.99% available | Higher purity grades for semiconductor use |
| Density | 2.2 g/cm³ | — |
| Maximum Continuous Use Temperature | 1100–1200°C | Grade-dependent; short-term up to 1700°C |
| Softening Point | 1670–1683°C | — |
| Annealing Point | 1215°C | — |
| Strain Point | 1120°C | — |
| Coefficient of Thermal Expansion | 0.54–0.6 ×10⁻⁶/°C (20–1000°C) | — |
| Thermal Conductivity | 1.4–1.46 W/m·K @20°C | — |
| Apparent Porosity | ≤15% | — |
| Compressive Strength | ~1100 MPa | — |
| Flexural Strength | ≥25 MPa (room temp); ≥28 MPa (high temp) | — |
Standard Dimensions
| Outer Diameter (mm) | Inner Diameter (mm) | Height (mm) | Approx. Capacity (mL) |
|---|---|---|---|
| 25 | 21 | 38 | 14 |
| 55 | 45 | 50 | 78 |
| 62 | — | 66 | 100 |
| 79 | — | 82 | 150 |
| 100 | 88 | 120 | — |
| 120 | 110 | 125 | — |
| 140 | 120 | 130 | — |
Custom sizes and geometries available upon request (cylindrical, tapered, deep-well, large-mouth).
Quality Assurance
Our fused quartz crucibles are manufactured under strict quality control standards. Typical trace impurity levels: Al₂O₃ ≤0.12%, Fe₂O₃ ≤0.02%, TiO₂ ≤0.018%, MgO ≤0.004%, Na₂O ≤0.004%, CaO ≤0.007%, K₂O ≤0.004%.
Test data and material certification available upon request for qualifying orders.
