to Alumina ceramics
to Properties of ceramics
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| Sapphire/Ruby, monocrystalline corundum (alpha alumina) | ||||
| Chemical composition: AL2O3 | ||||
| Property | Value in metric unit | Value in US unit | ||
| Density | 3.98 *10³ | kg/m³ | 248.4 | lb/ft³ |
|---|---|---|---|---|
| Modulus of elasticity | 430 | GPa | 62400 | ksi |
| Tensile strength | 414 | MPa | 60000 | psi |
| Compressive strength | 2400 | MPa | 350000 | psi |
| Modulus of rupture | 620 | MPa | 90000 | psi |
| Hardness | 2750 | HV | 2750 | HV |
| Thermal expansion (parallel to C-axis) | 6.7*10-6 | ºCˉ¹ | 3.7*10-6 | in/(in* ºF) |
| Thermal expansion (perpendicular to C-axis) | 5.0*10-6 | ºCˉ¹ | 2.8*10-6 | in/(in* ºF) |
| Thermal conductivity | 38 | W/(m*K) | 261 | BTU*in/(hr*ft²*ºF) |
| Specific heat capacity | 750 | J/(kg*K) | 0.18 | BTU/(lb*ºF) |
| Max. working temperature | 2000 | ºC | 3632 | ºF |
| Dielectric strength (DC) | 48 | KV/mm | 1220 | V/mil |
| Dielectric constant (1MHz) | 10 | - | 10 | - |