Engineering Porcelain vs. Machinable Glass-ceramic
Engineering porcelain belongs to the oxide-based engineering ceramics classification, while machinable glass-ceramic belongs to the glass and glass-ceramics. There are 25 material properties with values for both materials. Properties with values for just one material (2, in this case) are not shown.
For each property being compared, the top bar is engineering porcelain and the bottom bar is machinable glass-ceramic.
Metric UnitsUS Customary Units
Mechanical Properties
| Compressive (Crushing) Strength, MPa | 590 | |
| 310 |
| Elastic (Young's, Tensile) Modulus, GPa | 67 to 150 | |
| 67 |
| Flexural Strength, MPa | 43 to 160 | |
| 96 |
| Fracture Toughness, MPa-m1/2 | 2.0 | |
| 2.5 |
| Knoop Hardness | 600 | |
| 250 |
| Poisson's Ratio | 0.17 | |
| 0.29 |
| Shear Modulus, GPa | 34 | |
| 26 |
| Tensile Strength: Ultimate (UTS), MPa | 130 | |
| 84 |
Thermal Properties
| Maximum Temperature: Mechanical, °C | 1170 | |
| 760 |
| Specific Heat Capacity, J/kg-K | 600 to 1000 | |
| 790 |
| Thermal Conductivity, W/m-K | 1.8 to 6.5 | |
| 1.2 |
| Thermal Expansion, µm/m-K | 2.0 to 6.6 | |
| 21 |
Electrical Properties
| Dielectric Constant (Relative Permittivity) At 1 Hz | 5.0 to 10 | |
| 6.0 |
| Dielectric Constant (Relative Permittivity) At 1 MHz | 6.5 | |
| 6.4 |
| Dielectric Strength (Breakdown Potential), kV/mm | 11 to 25 | |
| 27 |
| Electrical Dissipation At 1 Hz | 0.0043 to 0.028 | |
| 0.0049 |
| Electrical Dissipation At 1 MHz | 0.00043 to 0.013 | |
| 0.0050 |
| Electrical Resistivity Order of Magnitude, 10x Ω-m | 9.0 to 12 | |
| 14 |
Otherwise Unclassified Properties
| Density, g/cm3 | 2.3 to 3.0 | |
| 2.7 |
Common Calculations
| Stiffness to Weight: Axial, points | 16 to 29 | |
| 14 |
| Stiffness to Weight: Bending, points | 49 to 65 | |
| 51 |
| Strength to Weight: Axial, points | 12 to 16 | |
| 8.8 |
| Strength to Weight: Bending, points | 19 to 25 | |
| 16 |
| Thermal Diffusivity, mm2/s | 0.73 to 3.9 | |
| 0.56 |
| Thermal Shock Resistance, points | 11 to 53 | |
| 4.3 |