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Machinable Glass Ceramic ( SiO2 46/Al2O3 16/MgO 17/K2O 10/B2O3 7 )

Material Information

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Common Brand Names:
MACOR®
 
General Description:  

This Machineable Ceramic is a white ceramic which can be machined with ordinary steel or carbide tools. It has been used extensively in the Space Shuttle Orbiter. It can be used continuously up to 800C and is a good electrical and thermal insulator. Outgassing in ultra-high vacuum environments can be eliminated, if degassed before use. MACOR® is non-wetting and can be bonded to itself as well as to various metals, if the MACOR® surfaces are first metallized.

   

Chemical Resistance

Acids - concentrated Poor
Acids - dilute Fair
Alkalis Fair

Electrical Properties

Dielectric constant 5.9
Dielectric strength ( kV mm-1 ) 40
Volume resistivity @25C ( Ohmcm ) >1014

Mechanical Properties

Compressive strength ( MPa ) 345
Hardness - Vickers ( kgf mm-2 ) 400
Tensile modulus ( GPa ) 67

Physical Properties

Apparent porosity ( % ) 0
Density ( g cm-3 ) 2.52

Thermal Properties

Coefficient of thermal expansion @20-1000C ( x10-6 K-1 ) 13
Specific heat @25C ( J K-1 kg-1 ) 790
Thermal conductivity @20C ( W m-1 K-1 ) 1.5
Upper continuous use temperature ( C ) 800-1000

Buy Machinable Glass Ceramic on-line

Standard products are available in these forms
Bar Rod Sheet
Bar Rod Sheet

Choose a form to search our on-line catalog  

Index