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 mm2/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