Fused Silica B Grade for Investment Casting
Fused Silica B Grade is a high-purity silica material specifically developed for investment casting shell systems, particularly for backup layers and structural reinforcement layers. With excellent thermal stability, low thermal expansion, and controlled particle size distribution, it ensures consistent shell strength and dimensional accuracy during casting.
This grade is widely adopted by foundries producing carbon steel, alloy steel, stainless steel, and superalloy components, especially where thermal shock resistance and shell integrity are critical.
Technical Specifications
Purity
- SiO₂ (Grains): ≥ 99.8%
- SiO₂ (Powders): ≥ 99.7%
High silica purity ensures minimal interaction with molten metal and reduces the risk of chemical contamination during pouring.
Chemical Composition (Typical)
Low alkali and iron content improves refractoriness, thermal stability, and shell cleanliness, making it suitable for demanding investment casting applications.
Particle Size Distribution (PSD – 6–50)
Grains
- +2.0 mm: 2–8%
- +1.0 mm: 40–60%
- +0.5 mm: 30–50%
- +0.212 mm: 2–8%
120F Powder
- +0.063 mm: 15–30%
- −0.063 mm: 60–80%
This optimized grain-to-powder ratio provides:
- Excellent shell permeability
- Strong mechanical bonding
- Uniform layer thickness
- Stable shell buildup
Application in Investment Casting
Fused Silica B Grade is mainly used in:
- Backup layers of ceramic shells
- Structural reinforcement layers
- Support layers for complex or large castings
Its controlled granulometry allows foundries to achieve:
- High shell strength
- Reduced cracking during drying and firing
- Improved resistance to thermal shock
- Stable performance during metal pouring
This makes it an ideal material for medium to large castings and high-temperature alloys.
Key Advantages
- High SiO₂ purity
- Low impurity levels
- Excellent thermal shock resistance
- Consistent particle size distribution
- Reliable shell strength and stability
Conclusion
Fused Silica B Grade is a proven and reliable material for investment casting backup layers, delivering consistent performance, strong shell structure, and excellent thermal behavior. It is a cost-effective solution for foundries seeking stable quality and repeatable casting results.