Hexoloy® SG SiC Material
Hexoloy® SG silicon carbide is a unique electrically conductive version of sintered silicon carbide.
The Hexoloy® SG grade offers a wide variety of useful properties in one package, including:
- Excellent hardness
- High corrosion resistance
- High temperature stability
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.
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.
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.
|Property||Units||Measurement Technique||Typical Values|
|Phases||-||X-ray Diffraction||SiC (6H, 4H, 15R), C|
|Density||gm / cm3||-||3.0|
|Hardness||kg / mm2||Knoop, 100 gm load||2,800|
|Flexural Strength (Room Temperature)||MPa||ASTM C-1161, 4-point||311|
|Weibull Modulus||-||ASTM C-1161, 4-point||18|
|Young's Modulus||GPa||Pulse Echo||376|
|Shear Modulus||GPa||Pulse Echo||161|
|Poisson Ratio||-||Pulse Echo||0.17|
|Fracture Toughness (Room Temperature)||MPa x m1/2||Indentation, 10 kg load||3.9|
|Fracture Toughness (Room Temperature)
RT to 700°C
|mm / mm K||Dilatometry||4.6|
|Mean Specific Heat @ RT||J / g K||Laser Flash ASTM E 1461-92||0.65|
|Thermal Conductivity @ RT||W / m K||Laser Flash ASTM E 1461-92||118|
|Thermal Conductivity @ 200°C||W / m K||Laser Flash ASTM E 1461-92||92|
|Thermal Conductivity @ 400°C||W / m K||Laser Flash ASTM E 1461-92||70|
|Electrical Resistivity||Ohm-cm||-||1.0 - 10.0|