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Machinable Glass-Ceramic

Machinable glass-ceramic is a glass-type material. It has the highest fracture toughness among the glass and glass-ceramics in the database. The graph bars on the material properties cards below compare machinable glass-ceramic to other glass and glass-ceramics (top) and the entire database (bottom). A full bar means this is the highest value in the relevant set. A half-full bar means it's 50% of the highest, and so on.

Mechanical Properties

Compressive (Crushing) Strength

310 MPa 44 x 103 psi

Elastic (Young's, Tensile) Modulus

67 GPa 9.7 x 106 psi

Flexural Strength

96 MPa 14 x 103 psi

Fracture Toughness

2.5 MPa-m1/2 2.3 x 103 psi-in1/2

Knoop Hardness

250

Poisson's Ratio

0.29

Shear Modulus

26 GPa 3.7 x 106 psi

Tensile Strength: Ultimate (UTS)

84 MPa 12 x 103 psi

Electrical Properties

Dielectric Constant (Relative Permittivity) At 1 Hz

6.0

Dielectric Constant (Relative Permittivity) At 1 MHz

6.4

Dielectric Strength (Breakdown Potential)

27 kV/mm 1.0 V/mil

Electrical Dissipation At 1 Hz

0.0049

Electrical Dissipation At 1 MHz

0.0050

Electrical Resistivity Order of Magnitude

14 10x Ω-m

Other Material Properties

Density

2.7 g/cm3 170 lb/ft3

Maximum Temperature: Mechanical

760 °C 1400 °F

Specific Heat Capacity

790 J/kg-K 0.19 BTU/lb-°F

Thermal Conductivity

1.2 W/m-K 0.68 BTU/h-ft-°F

Thermal Expansion

21 µm/m-K

Common Calculations

Stiffness to Weight: Axial

14 points

Stiffness to Weight: Bending

51 points

Strength to Weight: Axial

8.8 points

Strength to Weight: Bending

16 points

Thermal Diffusivity

0.56 m2/s

Thermal Shock Resistance

4.3 points

Followup Questions

Further Reading

CRC Materials Science and Engineering Handbook, 4th ed., James F. Shackelford et al. (editors), 2015