Polycrystalline CVD Diamond
CVD diamond is a non-oxide engineering ceramic. It has the highest tensile strength among non-oxide engineering ceramics. In addition, it has the highest thermal conductivity and a very low heat capacity. The graph bars on the material properties cards below compare CVD diamond to other non-oxide 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
Elastic (Young's, Tensile) Modulus
1050 GPa 150 x 106 psi
Fracture Toughness
5.5 MPa-m1/2 5.0 x 103 psi-in1/2
Poisson's Ratio
0.1
Tensile Strength: Ultimate (UTS)
750 MPa 110 x 103 psi
Thermal Properties
Specific Heat Capacity
500 J/kg-K 0.12 BTU/lb-°F
Thermal Conductivity
1900 W/m-K 1100 BTU/h-ft-°F
Thermal Expansion
1.0 µm/m-K
Electrical Properties
Dielectric Constant (Relative Permittivity) At 1 MHz
5.7
Electrical Dissipation At 1 MHz
0.00020
Electrical Resistivity Order of Magnitude
13 10x Ω-m
Otherwise Unclassified Properties
Density
3.5 g/cm3 220 lb/ft3
Light Transmission Range
0.22 to 100 µm
Refractive Index
2.4
Common Calculations
Stiffness to Weight: Axial
170 points
Stiffness to Weight: Bending
96 points
Strength to Weight: Axial
59 points
Strength to Weight: Bending
52 points
Thermal Diffusivity
1080 mm2/s
Thermal Shock Resistance
51 points
Followup Questions
Further Reading
Ceramics and Composites: Processing Methods, Narottam P. Bansal and Aldo R. Boccaccini (editors), 2012
Springer Handbook of Condensed Matter and Materials Data, W. Martienssen and H. Warlimont (editors), 2005