Ceramic Sand for Investment Casting: Advantages and Applications
Investment casting (also known as lost-wax casting) is a precision casting process that requires high-quality refractory materials to produce complex, near-net-shape metal parts. Ceramic sand ( ceramic beads) is increasingly used as a molding material in investment casting due to its superior properties compared to traditional silica sand or zircon sand.
Key Advantages of Ceramic Sand in Investment Casting
1. High Refractoriness & Thermal Stability
Extreme heat resistance (≥1800°C), making it ideal for superalloys (e.g., Inconel, titanium, stainless steel).
Low thermal expansion (only ~10% of silica sand), reducing shell cracking and deformation during casting.
2. Spherical Shape for Superior Mold Quality
Smooth surface finish – minimizes metal penetration and improves casting surface quality.
High packing density (68-72%) – reduces binder usage while maintaining shell strength.
Excellent flowability – ensures uniform coating in slurry dipping processes.
3. Reduced Defects in Castings
Lower gas porosity – inert material prevents gas generation during pouring.
Minimized veining & cracking – low thermal expansion prevents mold failure.
Less metal penetration – dense structure prevents molten metal from seeping into the mold.
4. Cost Efficiency & Reusability
High recyclability (up to 90% reuse rate) – lowers material costs over time.
Less binder required – due to high packing density, reducing shell-making expenses.
5. Environmental & Health Benefits
No free silica (SiO₂) – eliminates silicosis risk for workers.
Chemically inert – no reactions with molten metal, reducing slag and inclusions.
| Sieve | 10# | 20# | 30# | 40# | 50# | 70# | 100# | 140# | 200# | 270# | PAN | AFS |
| um | 1700 | 850 | 600 | 425 | 300 | 212 | 150 | 106 | 75 | 53 | PAN | |
| 20-40# | 15-40% | 30-55% | 15-35% | ≤3% | 15-25 | |||||||
| 30-50# | ≤10% | 25-45% | 35-55% | 5-15% | ≤5% | ≤2% | 25-29 | |||||
| 40-70# | ≤10% | 25-45% | 20-40% | 5-25% | ≤7% | ≤5% | 35-39 | |||||
| 40-100# | ≤3% | 10-25% | 25-40% | 25-45% | 10-25% | ≤10% | ≤5% | 45-55 | ||||
| 50-100# | ≤10% | 10-30% | 30-50% | 15-35% | ≤15% | ≤5% | ≤2% | ≤1% | 55-65 | |||
| 50-140# | ≤8% | 10-25% | 20-45% | 20-45% | 5-20% | ≤7% | ≤2% | ≤1% | 60-70 | |||
| 70-140# | ≤10% | 10-25% | 25-45% | 15-35% | ≤15% | ≤5% | ≤2% | 75-85 | ||||
| 100-200# | ≤3% | 10-35% | 35-55% | 15-35% | ≤10% | ≤5% | 95-115 | |||||
| 140-270# | ≤5% | 5-25% | 40-60% | 25-40% | ≤15% | 155-175 | ||||||
| 6-20# | LOST FOAM CASTING | |||||||||||
Applications in Investment Casting
Ceramic sand is particularly suitable for:
✔ High-temperature alloys (turbine blades, aerospace components).
✔ Precision castings (medical implants, automotive parts).
✔ Complex thin-walled parts (where dimensional accuracy is critical).