Hexoloy® SE SiC Material
Material Properties
Hexoloy® SE SiC is an excellent alternative to metals, superalloys, graphite, and other ceramics. It is highly suited for applications in heat exchangers, chemical processing, high temperature furnaces, and other demanding, severe environments. Hexoloy® SE SiC offers a full range of exceptional properties in one package, including:
- Extreme hardness
- High strength
- Virtually universal corrosion resistance
- High temperature stability
- High thermal conductivity
Hexoloy® SE SiC is produced by the pressure-less sintering of submicron silicon carbide powder in a proprietary extruding process. The sintering process results in a self-bonded, single phase, fine grained (less than 10 μm) SiC product.
Customized Hexoloy® SE SiC extruded components can supplied to meet customer specifications.
Hexoloy® SE SiC is one of the hardest, high performance materials available. It is 50% harder than tungsten carbide, its density is in excess of 95% theoretical and it is completely impervious, even without the use of an impregnate.
This is especially beneficial in high purity applications where contamination is a key issue.
How Saint-Gobain Performance Ceramics & Refractories manufactures its precision engineered Hexoloy® sintered silicon carbide products?
Saint-Gobain Performance Ceramics & Refractories pioneered the technology to manufacture a pressureless sintered silicon carbide material - Hexoloy® - in the late 1970s.
Forming Options
Economical forming is determined by shape, quantity volume and tolerances of the final part.
Dry pressing to size is the most economical forming method for volumes of 300 pieces or more, which helps justify the initial expense of tooling designed specifically for each part.
Isostatic pressing is best suited to low volumes and prototype items.
Pre-Sinter (Green) Machining
Machining in the pre-sintered, or green, state is desirable because it allows manufacturing of complex finished shapes without expensive grinding of sintered material.
Green machining is accomplished using conventional processes. Stock removal can be accomplished 15 times faster in the green state than in the sintered state.
Green machining provides parts to tolerances of 0.5% to 1.0% of their final dimensions. Typical green machined surface finishes range between 32 and 64 µin.
Grinding and Finishing
Precision grinding capabilities have been developed to meet the exacting specification requirements required by the automotive, aerospace and nuclear industries.
Saint-Gobain Performance Ceramics & Refractories has the expertise to grind to close tolerances on most shapes (.0005").
Typical ground parts hold finishes of 16 µin or better. When surface finishes are critical in improving friction and wear performance, finishing operations can improve surfaces up to 4 µin providing surface flatness to one helium light band.
Quality Assurance
Saint-Gobain Performance Ceramics & Refractories maintains the highest level of quality by leveraging state-of-the-art, non-destructive evaluation equipment for final quality inspections of internal structures.
These techniques include bulk and surface wave ultrasonics, fluorescent dye penetrant, radiography, acoustic emission, and photomicrography.
Specifications
| Property | Typical Values |
| Maximum Use Temperature | 1,900°C |
| Flexural Strength (MPa) | |
| @ Room Temp | 280 |
| @ 1,450°C | 270 |
| @ 1,600°C | 300 |
| Density (g / cc) | 3.05 |
| Apparent Porosity (%) | |
| Modulus of Elasticity (GPa) | |
| @ 20°C | 420 |
| @ 1,300°C | 363 |
| Thermal Conductivity (W / mK) @ 1,200°C | 34.8 |
| Coefficient of Thermal Expansion | 4.02 x 10-6 / °C |
