Zirconia-Toughened Alumina (ZTA)
ZTA is a grade of alumina. It has the highest strength compared to the other variants of alumina. The graph bars on the material properties cards below compare ZTA 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
2750 MPa 400 x 103 psi
Elastic (Young's, Tensile) Modulus
360 GPa 51 x 106 psi
Flexural Strength
430 MPa 63 x 103 psi
Fracture Toughness
7.2 MPa-m1/2 6.5 x 103 psi-in1/2
Knoop Hardness
1660
Poisson's Ratio
0.24
Tensile Strength: Ultimate (UTS)
290 MPa 42 x 103 psi
Thermal Properties
Maximum Temperature: Mechanical
1530 °C 2780 °F
Maximum Thermal Shock
300 °C 580 °F
Melting Onset (Solidus)
2040 °C 3700 °F
Specific Heat Capacity
870 J/kg-K 0.21 BTU/lb-°F
Thermal Conductivity
25 W/m-K 14 BTU/h-ft-°F
Thermal Expansion
8.2 µm/m-K
Other Material Properties
Density
4.1 g/cm3 260 lb/ft3
Dielectric Constant (Relative Permittivity) At 1 MHz
11
Dielectric Strength (Breakdown Potential)
8.9 kV/mm 0.35 V/mil
Electrical Dissipation At 1 MHz
0.00050
Electrical Resistivity Order of Magnitude
13 10x Ω-m
Common Calculations
Stiffness to Weight: Axial
48 points
Stiffness to Weight: Bending
57 points
Strength to Weight: Axial
19 points
Strength to Weight: Bending
24 points
Thermal Diffusivity
6.9 mm2/s
Thermal Shock Resistance
7.1 points
Followup Questions
Further Reading
Ceramic and Glass Materials: Structure, Properties and Processing, James F. Shackelford and Robert H. Doremus (editors), 2008
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