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MACOR®

Machinable Glass Ceramic (MGC)

Special Properties

  • Machineable glass-ceramic material that can be processed with conventional metalworking equipment
  • No glass processing machines required
  • The coefficient of thermal expansion is close to many metals and sealing glasses
  • High-temperature resistance
  • Non-porous
  • Dimensionally stable
  • No outgassing
  • Odorless opaque white material
  • Sealing with fusing glass is possible
  • Good insulator
  • Available as semi-finished rod, bar, and sheet materials

Typical Applications

  • Flight and aerospace industry
  • Substrates for field ion microscopes
  • Ultra-high vacuum and continuous vacuum applications
  • Medical equipment
  • Electrical contact holders
  • Laser cavity components
  • Welding nozzles
  • Bushing tubes
  • Mounting brackets
  • Laser adjustment components
  • High precision workpieces

Related ceramic products and pages

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An exceptional material that can be machined,

almost like metal

MACOR® machinable glass-ceramic from CORNING is a white-appearing odorless, and opaque material. It is composed of 55 % MIKA and 45 % borosilicate glass. You can find the detailed material composition in this spec sheet.

MACOR® is an advanced high-performance Small machined parts made of MACOR® glass ceramic from CORNING glass ceramic that offers exceptional properties for a broad range of workpiece designs in the industry. It allows the rapid production of complex shapes and precise workpieces with tight tolerances. MACOR glass-ceramic material is CNC-machined with conventional HSS equipment used for metal processing. Hence, expensive glass processing machinery and diamond tools are usually not required to process MACOR. Learn more about handling and processing MACOR® correctly in our processing instructions.

 

Finished glass ceramic part made of MACOR®
nullspacer Fig.: Finished mechanical component machined from MACOR® glass-ceramic.

 

MACOR® high-tech glass ceramic goes to the limits

The possible long-term use at 800°C and an allowed load-free peak temperature of up to 1.000°C of MACOR facilitate various sophisticated industrial applications. Corning's unique glass ceramic has zero porosity and is non-wetting. MACOR® does not deform or outgas and allows use in vacuum environments. The glass-ceramic material is an excellent insulator for high voltages at various frequencies, even at a high operating temperature. MACOR sets an industrial standard for machinable glass ceramics that other materials can hardly outperform. Therefore, it is ideal for aerospace applications, medical and semiconductor technology, and other demanding tasks.

 

From semi-finished material to finished workpieces

MACOR glass-ceramic raw materials are available from stock in sheets, square bars, and round rods at a short lead time (see table). These semi-finished products allow machining to very complicated shapes.

 

Components of MACOR® glass ceramic nullspacer You are welcome to request a quotation for a custom-finished workpiece made of original MACOR® glass ceramic.


To send an inquiry for any semi-finished standard MACOR® rod, bar, or sheet glass-ceramic product or a finished MACOR® workpiece with individual shapes and dimensions, please click the button below:


Request for Quotation

 

Specifications & Properties


Semi-Finished Standard Products:

MACOR® Rods, Bars, and Sheets

MACOR® Rods
Rod Diameter
(mm)		 Rod lengths
(mm)
3 70
4 70
6 70
8 70
12,5 70
19 75, 150, 300
25 75, 150, 300
30 75, 150, 300
38 75, 150, 300
50 75, 150, 300

MACOR® Bars
Bar Dimension
(mm x mm)
Bar lengths
(mm)
12,5 × 12,5 75, 150, 300
19 × 19 75, 150, 300
25 × 25 75, 150, 300
30 × 30 75, 150, 300
50 × 50 75, 150, 300

MACOR® Sheets
Sheet size
l x w
(mm)		 Sheet thickness
(mm)
75 × 75 12,5, 19, 25, 30, 50
150 × 150 12,5, 19, 25, 30, 50
300 × 300 12,5, 19, 25, 30, 50

The typical lead time for the standard MACOR® glass-ceramic rods, bars, and sheets listed above is approximately one week or less. The lead time can be longer for the large rod, bar, and sheet materials. Please send us your request.

 

MACOR® Glass Ceramic Machining Guidelines

Density

  • 2,52 g/cm3

Coefficient of Thermal Expansion

  • 74 × 10-7 / °C (-200–25 °C)
  • 93 × 10-7 / °C (25–300 °C)
  • 114 × 10-7 / °C (25–600 °C)
  • 126 × 10-7 / °C (25–800 °C)

Thermal Characteristics

  • Continuous operating temperature: 800 °C
  • Max. operating temperature: 1.000 °C (no load)
  • Thermal Diffusivity (25°C): 7,3 × 10-7 m2/s
  • Thermal Conductivity (25°C): 1,46 W/m°C
  • Specific Heat (25°C): 0,79 KJ / kg°C

Mechanical Characteristics

  • Porosity: 0 %
  • Young's Modulus (25 °C): 66,9 GPa
  • Poisson's Ratio: 0,29
  • Shear Modulus (25 °C): 25,5 GPa
  • Knoop Hardness (100 g): 250
  • Modulus of Rupture (25 °C): 94 MPa
  • Compressive Strength: 345 MPa
  • Fracture Toughness: 1,53 MPa m0,5

Electrical Characteristics

  • Dielectric Constant (25°C): 6,03 (1 kHz)
  • Dielectric Loss Tangent (25 °C): 4,7 x 10-3 (1 kHz)
  • Dielectric Strength (25 °C): 40 kV / mm
    (at 0,254 mm thickness)
  • Volume Resistivity: >1016 Ω-cm
Very small work pieces of MACOR® glass ceramic nullspacer MACOR® machinable glass ceramic materials from CORNING allow the design of tiny and intricate parts that require machining with high precision. If you have any questions, please contact us.


Composition of MACOR Glass Ceramic

Substance approximate weight
percentage
Silicon Oxide (SiO2) 46
Magnesium Oxide (MgO) 17
Alumina (Al2O3) 16
Potassium oxide (K2O) 10
Boron oxide (B2O3) 7
Fluorine (F) 4

Chemical Properties

Medium

pH

Time
(h)

Temp.
(°C)

Weight loss
(mg/cm2)
5 % HCL
0,1
24 h
95 °C
ca. 100
0,002 N HNO3
2,8
24 h
95 °C
ca. 0,6
0,1 N NaHCO3
8,4
24 h
95 °C
ca. 0,3
0,02 N Na2CO3
10,9
6 h
95 °C
ca. 0,1
5 % NaOH
13,2
6 h
95 °C
ca. 10
H2O (water)
7,6
24 h
95 °C
ca. 0,01

All details and specifications provided here are mean reference values and are not guaranteed. Also, please consider our "Notes on specifications".

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