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MACOR®

Machinable Glass Ceramic (MGC)

Special Properties

  • Machinable with conventional metalworking equipment
  • The coefficient of thermal expansion is close to that of many metals and sealing glasses
  • High-temperature resistance
  • Non-porous
  • Dimensionally stable
  • No outgassing
  • Odorless, opaque, white material
  • Excellent electrical insulation
  • Available as semifinished rod, bar, and sheet materials

Typical Applications

  • High-precision workpieces
  • Contact holders, bushings, and feedthroughs
  • Flight and aerospace industry
  • Substrates for field ion microscopes
  • Ultra-high vacuum and continuous vacuum applications
  • Medical equipment
  • Laser cavity components
  • Insulator for connectors in electronics
  • Welding nozzles
  • Bushing tubes
  • Mounting brackets
  • Laser adjustment components

Related ceramic materials

  • SHAPAL™ Hi M-soft
    (machinable aluminum nitride ceramic)
  • Al2O3
    (alumina high-performance ceramic)

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MACOR® machinable glass ceramic made by CORNING is a white-appearing, odorless, and opaque material composed of 55 % MIKA and 45 % borosilicate glass. The high-performance Small machined parts made of MACOR® from CORNING glass ceramic offers ideal properties for a broad range of workpiece designs in the industry. MACOR® allows the manufacturing of complex shapes and precise workpieces with tight tolerances. The glass ceramic can be CNC machined using conventional HSS tools commonly used for machining metal. Hence, expensive specialized machinery and diamond tooling is usually not required to process MACOR® material. Learn more about the processing parameters of MACOR® in our machining guidelines.

 

Finished part made of MACOR® MGC
nullspacer Fig.: A finished component with tight tolerances machined from MACOR® MGC

 

MACOR® can be used long-term at up to 800 °C and withstands a load-free peak temperature of up to 1000 °C. Moreover, CORNING's unique glass ceramic has zero porosity and is non-wetting. MACOR® does not deform or outgas allowing it to be used in vacuum environments. The material is an excellent insulator for high voltages at various frequencies, even at high temperatures. MACOR® sets an industrial standard for machinable glass ceramics that other MGC materials can hardly outperform. It is ideal for a wide range of applications in the aerospace, medical, and semiconductor industries.

 

Semifinished raw materials

We stock MACOR® material as semifinished products in the form of sheets, rods, and round bars (see table) with short delivery times. These semifinished products are the starting material for complex shaped workpieces.

 

Components of MACOR® glass ceramic nullspacer

Request customized parts made of original MACOR® machinable glass-ceramic according to your requirements.

 

To get a quote for semifinished MACOR® materials or a finished MACOR® part with customized shape and dimensions according to your drawing, please click on the button below:


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Specifications and Properties


Semifinished MACOR® raw material:

MACOR® Rods

Diameter
(mm)
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

Dimension
(mm × mm)
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

Size
l × w
(mm)
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 MACOR® materials listed above are available approximately within one week or less. It can take longer for the largest dimensions. Please send us your inquiry.

 

MACOR® MGC 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: 1000 °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® nullspacer MACOR® machinable glass ceramic from CORNING allows the design of such tiny and intricate parts that require a high precision. If you need supplemental information, please get in touch.


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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Last update: 15.02.2024