Lithafrax® Fillers

Lithium Aluminum Silicate Based Powder

Saint-Gobain Performance Ceramics & Refractories’ near zero thermal expansion inorganic fillers are a compound of lithium alumino-silicate materials.

Lithafrax® powders are thermally stable and ROHS compliant crystalline compounds of the formula LiAlSixOy with near zero thermal expansion coefficients. They are designed to be added as a filler for lowering the coefficient of thermal expansion (CTE) of a matrix.

Lithafrax® powders have provided the foundation for proven solutions in the aerospace, military, electronics, automotive, labware, and sustainable building and habitat markets for over 10 years.

These fillers have been successfully employed in lowering thermal expansion of thermoset resins, including epoxy and urethanes, frits and glasses, and specialty adhesives used in bonding and encapsulation of microelectronics, and as potting compounds.

Features and Benefits

  • Near zero thermal expansion
  • Low density
  • High loading potential
  • Aerospace
  • Semi-conductor Packaging
  • Coatings on Glassware
  • Electronics
Chemical Properties

Typical Chemical Properties of Lithafrax®

Chemical Grade 2121 Grade 2122
Li2O 11 - 13 3 - 5
Al2O3 35 - 40  15 - 20 
SiO2 45 - 50 75 - 80
Physical Properties

 Typical Physical Properties of Lithafrax®

  Cream White
Sieve -140 mesh -140 mesh
Particle Size 95% 325 mesh (-) 95% 325 mesh(-)
Horiba PSA D50 (light scattering) 2.8 +/- 1.0µm 2.8 +/- 1.0µm
Bulk Density (lbs./cu.ft.)    
Free Fall 40 42
48 50
True Density (g/cc) 2.37 to 2.43 2.40 to 2.47
Thermal Stability to 2,300°F to 2,300°F
Coefficient of Thermal Expansion (ppm/°C)    
50° - 200°C -2.2 x 10-6 1.2 x 10-6
50° - 500°C -3.6 x 10-6 N/A
pH 9.0 - 10.5 7.5 - 8.0


Why are low thermal expansion fillers needed?

Low thermal expansion fillers serve a very useful purpose of modifying properties of resins, frits, glasses, and coatings. These engineered materials are oftne used as potting compounds or adhesives. As such, low thermal expansion is key to improve the physical stability of the bond when application temperature changes.

What makes Saint-Gobain Performance Ceramics & Refractories’ low thermal expansion fillers unique?

Saint-Gobain Performance Ceramics & Refractories’ low thermal expansion fillers offer some of the lowest thermal expansion available in the market. For example, Lithafrax® 2121 actually has a negative coefficient of thermal expansion up to 200°C.

What are the other advantages of Lithafrax®?

Compared to other commonly used fillers, Lithafrax® fillers are lower density, higher purity crystalline materials. They can be used for high loading without significantly altering the properties of a matrix.