Optical Materials
  Optical Glass
  Low Expansion Materials
  IR Materials
Micro-Optical Components
Fiber Optic Components
Light Sources & Photodiodes

Miscellaneous Low Expansion Materials

Other low expansion materials include ultra low expansion (ULE®) titanium silica glass and VYCOR® brand glass form Corning Incorporated, and CLERACREAM®-Z glass ceramic from OHARH.

Corning titanium silica glass has the unique characteristics of a low thermal expansion coefficient, light density and excellent resistance to chemical attacks. These properties have made it the material of choice in applications ranging from machine tool reference blocks to solid and lightweight mirror blanks for larger astronomical telescopes and space satellite applications. The 2.4-meter primary mirror for the Hubble space Telescope is made from Corning ULE glass.

  Mean Coefficient of Expansion
°C to 35 °C (/°K)
  Thermal Conductivity (W/m·°C) 1.31
  Strain Point (°C) 890
  Annealing Point (°C) 1000
  Softening Point (°C) 1490
  Density (g/cm3) 2.21  
  Young's Modulus (GPa) 67.6
  Poisson's Ratio 0.17
  Shear Modulus (GPa) 29
  Knoop Hardness 460
  Table 1:Coring Titanium Silica Glass Properties

Both VYCOR brand porous glass 7930 and VYCOR 7913 have low thermal expansion and excellent resistant to thermal shocks. VYCOR glass 7930 is an open cell, porous glass which exhibits excellent absorbing properties. The open-cell network allows permeability on a selective basis and the glass 7930 is often used for filtration and separation of compounds. VYCOR 7913 can be used at continuous temperatures up to 900°C. This feature permits the use of fluctuating thermal sources, such as arc lamps and other high-intensity sources.

  Coefficient of Expansion
°C to 300 °C (/°C)
  Strain Point (°C) 890
  Annealing Point (°C) 1020
  Softening Point (°C) 1530
  Density (g/cm3) 2.18  
  Young's Modulus (GPa) 66.2
  Poisson's Ratio 0.19
  Shear Modulus (GPa) 27.9
  Knoop Hardness 487
  Table 2:VYCOR Glass Properties

CLEARCERAM-Z (CCZ) is glass ceramic with an ultra-low thermal expansion and offers outstanding thermal, mechanical and chemical properties. There are two versions of CLEARCERAM-Z; CCZ Regular and CCZHS. CCZ Regular offers low thermal expansion across a wide temperature range, while CCZHS offers lower thermal expansion near room temperature. Both materials offer superior thermal shock resistance, mechanical properties and excellent resistance to chemical attacks.


Figure 1: Thermal expansion curves for CLEARCERAM-Z (Temperature Range: 0~50 °C )


Figure 2: Thermal expansion curves for CLEARCERAM-Z (Temperature Range: -60~160 °C )

  Optical Properties
435.83 404.65  
t C' d e F' g h  
  Refractive Index
Regular Grade
1.53499 1.54357 1.54607 1.54841 1.55350
1.55838 1.56300  
  Refractive Index
HS Grade
1.53545 1.54409 1.54662 1.54899 1.55415
1.55913 1.56387  
  Table 3:Optical properties of CLEARCERAM-Z


  Density (g/cm3)
Regular Grade
  HS Grade
  Poisson's Ratio
Regular Grade 0.25
  HS Grade 0.25
  Knoop Hardness
Regular Grade 600
  HS Grade 640
  Young's Modulus (GPa) Regular Grade 90
  HS Grade 90
         Table 4:Mechanical properties of CLEARCERAM-Z  

Low Expansion Materials :  

Copyright © 2016 Precision Micro-Optics Inc. All Rights Reserved.