MACOR®

Machinable Glass Ceramic

MACOR® is a white, non-wetting, zero porosity, extremely machinable ceramic material for technical and industrial applications. Unlike ductile materials, MACOR® will not deform. It is an excellent insulator at high voltages, various frequencies and high temperatures.

MACOR’s® composition comprises 55% fluorophlogopite mica and 45% borosilicate glass. Corning's unique production process results in MACOR’s® microstructure that is key to its versatile properties.

Thermal:

Coefficient of Expansion                     

CTE -100^oC to 25^oC                               81 x 10⁷/^oC

CTE 25^oC to 300^oC                                90 x 10⁷/^oC

CTE 25^oC to 600^oC                                112 x 10⁷/^oC

CTE 25^oC to 800^oC                                123 x 10⁷/^oC

Specific Heat, 25^oC                                                       0.79 kj/kg^oC

Thermal Conductivity, 25^oC                                        1.46 W/m^oC

Thermal Diffusivity, 25^oC                                             7.3 x 10⁷ m³/s

Continuous Operating Temperature    800^oC

Maximum No Load Temperature          1000^oC



 Mechanical:

Density                                       2.52 gm/cm³

Porosity                                       0%

Young’s Modulus, 25^oC            66.9 GPa

Poisson’s Ratio                         0.29

Shear Modulus, 25^oC               25.5 GPa

Knoop Hardness, 100 gm        250 kg/mm³

Flexural Strength, 25^oC            94 MPa (minimum average value)

Compressive Strength             345 MPa (up to 9000 MPa after polishing)



Electrical:

Dielectric Constant, 25^oC (1 kHz)            6.01

Dielectric Constant, 25^oC (8.5 GHz)        5.64

Loss Tangent, 25^oC (1 kHz)                      0.0040

Loss Tangent, 25^oC (8.5 GHz)                  0.0025

Dielectric Strength (AC) average            45 kV/mm (25^oC, under 0.03 mm thickness)

Dielectric Strength (DC) average            129 kV/mm (25^oC, under 0.03 mm thickness)

DC Volume Resistivity, 25^oC                    10¹⁷ Ohm.cm



Chemical:

                                            Weight Loss

Solution                     pH         Time         Temp.       Gravimetric (mg/cm²)

5% HCl                         0.1         24 hrs          95^oC          ~100

0.002 N HNO₃            2.8         24 hrs          95^oC              ~0.6

0.1 N NaHCO₃            8.4         24 hrs          95^oC              ~0.3

0.02 N Na₂CO₃         10.9          6 hrs          95^oC               ~0.1

                                   5% NaOH                   13.2          6 hrs          95^oC              ~10



Product Keys:

• Easily machinable
• Withstands high temperatures
• Low thermal conductivity   
• Holds tight tolerances         
• Electrical insulator 
• Zero porosity and no outgassing
• Strong and ridged   
• Highly polishable
• Can be soldered to a wide range of materials   
• Radiation resistant   
• lead free

Applications:

• Constant and ultra-high vacuum environments
• Laser technology   
• Semiconductor and Electrical
• Aerospace and Space Sciences
• Medical and Laboratory Equipment
• Fixtures
• Chemical
• Automobile
• Military
• Nuclear

Forms:

MACOR® Machinable Glass Ceramics are available in slab and rod forms. It can be custom machines in many precision parts.

Macor® is manufactured by the Corning Incorporated, Specialty Materials Division.