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Mica-Containing Glass-Ceramic (IEC 60672 Type GM-120)

GM-120 glass ceramic is a glass-type material. It has a moderately low dielectric strength among the glass and glass-ceramics in the database. The graph bars on the material properties cards below compare GM-120 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.

Thermal Properties

Maximum Thermal Shock

110 °C 230 °F

Thermal Conductivity

3.0 W/m-K 1.7 BTU/h-ft-°F

Thermal Expansion

9.5 µm/m-K

Electrical Properties

Dielectric Strength (Breakdown Potential)

11 kV/mm 0.45 V/mil

Electrical Resistivity Order of Magnitude

10 10x Ω-m

Other Material Properties


2.5 g/cm3 150 lb/ft3

Elastic (Young's, Tensile) Modulus

56 GPa 8.1 x 106 psi

Flexural Strength

57 MPa 8.3 x 103 psi

Common Calculations

Stiffness to Weight: Axial

13 points

Stiffness to Weight: Bending

52 points

Followup Questions

Further Reading

IEC 60672-3: Ceramic and glass-insulating materials - Part 3: Specifications for individual materials

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