Engineering Porcelain vs. Alumina

Both engineering porcelain and alumina are oxide-based engineering ceramics. There are 25 material properties with values for both materials. Properties with values for just one material (3, in this case) are not shown.

For each property being compared, the top bar is engineering porcelain and the bottom bar is alumina.

Engineering Porcelain Alumina (Aluminum Oxide, Al₂O₃)

Metric UnitsUS Customary Units

Mechanical Properties

Compressive (Crushing) Strength, MPa		590
Compressive (Crushing) Strength, MPa		1920 to 2750

Elastic (Young's, Tensile) Modulus, GPa		67 to 150
Elastic (Young's, Tensile) Modulus, GPa		220 to 370

Flexural Strength, MPa		43 to 160
Flexural Strength, MPa		260 to 430

Fracture Toughness, MPa-m^1/2		2.0
Fracture Toughness, MPa-m^1/2		3.7 to 7.2

Knoop Hardness		600
Knoop Hardness		960 to 1660

Poisson's Ratio		0.17
Poisson's Ratio		0.22 to 0.24

Tensile Strength: Ultimate (UTS), MPa		130
Tensile Strength: Ultimate (UTS), MPa		210 to 290

Thermal Properties

Maximum Temperature: Mechanical, °C		1170
Maximum Temperature: Mechanical, °C		650 to 1730

Maximum Thermal Shock, °C		170 to 290
Maximum Thermal Shock, °C		200 to 300

Specific Heat Capacity, J/kg-K		600 to 1000
Specific Heat Capacity, J/kg-K		870 to 940

Thermal Conductivity, W/m-K		1.8 to 6.5
Thermal Conductivity, W/m-K		14 to 30

Thermal Expansion, µm/m-K		2.0 to 6.6
Thermal Expansion, µm/m-K		6.7 to 8.2

Electrical Properties

Dielectric Constant (Relative Permittivity) At 1 Hz		5.0 to 10
Dielectric Constant (Relative Permittivity) At 1 Hz		8.0 to 9.0

Dielectric Constant (Relative Permittivity) At 1 MHz		6.5
Dielectric Constant (Relative Permittivity) At 1 MHz		7.8 to 11

Dielectric Strength (Breakdown Potential), kV/mm		11 to 25
Dielectric Strength (Breakdown Potential), kV/mm		8.9 to 12

Electrical Dissipation At 1 Hz		0.0043 to 0.028
Electrical Dissipation At 1 Hz		0.00031 to 0.0011

Electrical Dissipation At 1 MHz		0.00043 to 0.013
Electrical Dissipation At 1 MHz		0.00049 to 0.0013

Electrical Resistivity Order of Magnitude, 10^x Ω-m		9.0 to 12
Electrical Resistivity Order of Magnitude, 10^x Ω-m		6.2 to 14

Otherwise Unclassified Properties

Density, g/cm³		2.3 to 3.0
Density, g/cm³		3.4 to 4.1

Common Calculations

Stiffness to Weight: Axial, points		16 to 29
Stiffness to Weight: Axial, points		35 to 53

Stiffness to Weight: Bending, points		49 to 65
Stiffness to Weight: Bending, points		57 to 62

Strength to Weight: Axial, points		12 to 16
Strength to Weight: Axial, points		14 to 23

Strength to Weight: Bending, points		19 to 25
Strength to Weight: Bending, points		19 to 28

Thermal Diffusivity, mm²/s		0.73 to 3.9
Thermal Diffusivity, mm²/s		3.7 to 10

Thermal Shock Resistance, points		11 to 53
Thermal Shock Resistance, points		4.9 to 14