Grade A Lava (Alumina Silicate)
Grade A lava is an oxide-based engineering ceramic. It can have a moderately low dielectric strength among oxide-based engineering ceramics. In addition, it can have a moderately low tensile strength and a moderately low density.
The properties of grade A lava include two common variations. This page shows summary ranges across both of them. For more specific values, follow the links immediately below. The graph bars on the material properties cards further below compare grade A lava to other oxide-based engineering 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
76 to 170 MPa 11 to 25 x 103 psi
Flexural Strength
28 to 69 MPa 4.0 to 10 x 103 psi
Tensile Strength: Ultimate (UTS)
6.9 to 21 MPa 1.0 to 3.0 x 103 psi
Thermal Properties
Maximum Temperature: Corrosion
1150 °C 2100 °F
Maximum Temperature: Mechanical
650 to 1130 °C 1200 to 2060 °F
Specific Heat Capacity
840 J/kg-K 0.2 BTU/lb-°F
Thermal Conductivity
2.0 W/m-K 1.2 BTU/h-ft-°F
Thermal Expansion
2.5 to 3.3 µm/m-K
Electrical Properties
Dielectric Constant (Relative Permittivity) At 1 MHz
5.3 to 5.8
Dielectric Strength (Breakdown Potential)
3.2 to 3.9 kV/mm 0.12 to 0.15 V/mil
Otherwise Unclassified Properties
Density
2.3 to 2.5 g/cm3 140 to 160 lb/ft3
Water Absorption At Saturation
2.5 %
Common Calculations
Strength to Weight: Axial
0.77 to 2.5 points
Strength to Weight: Bending
3.2 to 7.3 points
Thermal Diffusivity
1.0 mm2/s
Followup Questions
Further Reading
Springer Handbook of Condensed Matter and Materials Data, W. Martienssen and H. Warlimont (editors), 2005
CRC Materials Science and Engineering Handbook, 4th ed., James F. Shackelford et al. (editors), 2015