Potassium Chloride (KCl) Optical Material
Potassium chloride is a non-glass, inorganic optical material. It has the lowest density among the non-glass optical ceramics in the database. The graph bars on the material properties cards below compare potassium chloride to other non-glass optical 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
Elastic (Young's, Tensile) Modulus
28 GPa 4.0 x 106 psi
Poisson's Ratio
0.18
Shear Modulus
8.5 GPa 1.2 x 106 psi
Thermal Properties
Melting Onset (Solidus)
780 °C 1440 °F
Specific Heat Capacity
690 J/kg-K 0.16 BTU/lb-°F
Thermal Conductivity
6.5 W/m-K 3.8 BTU/h-ft-°F
Thermal Expansion
36 µm/m-K
Electrical Properties
Dielectric Constant (Relative Permittivity) At 1 MHz
4.6
Electrical Dissipation At 1 MHz
0.00010
Otherwise Unclassified Properties
Density
2.0 g/cm3 120 lb/ft3
Light Transmission Range
0.21 to 20 µm
Refractive Index
1.6
Common Calculations
Stiffness to Weight: Axial
7.7 points
Stiffness to Weight: Bending
51 points
Thermal Diffusivity
4.7 mm2/s
Followup Questions
Further Reading
Handbook of Optical Materials, Marvin J. Weber, 2003
Handbook of Optical Constants of Solids, Edward D. Palik (editor), 1998