| Sapphire Crystal structure Mechanical properties Optical Properties Thermal properties Electrical properties Chemical resistance |
| Crystal
structure: |
|
| Chemical composition: | Al2O3 |
| Molecular weight: | 101.96 |
| Crystal system: | Rhombohedral
systems(R3c) Click to enlarge |
| Lattice constant: | a=4.765A/c=13.001A* A=10 nm |
| Density (specific gravity): | 3.98 g/cm3 |
| Cleavability: | (1011), (1120), imperfect |
|
Mechanical
properties:
|
|
| Hardness: | [Mohs]
9(*Diamond=10, quartz=7) [Knoop] 15.0 to 16.3GPa (perpendicular to the c axis) 16.4 to 19.6GPa (parallel to the c axis) [Vickers] 2300 |
| Young's modulus: | 34 to 37 GPa |
| Crushing strength: | 2000 Mpa |
| Tensile strength: | 2250 Mpa |
| Compression strength: | 2950 Mpa |
| Bending strength: | 450 to 690 Mpa |
| Destruction coefficient: | 490 to 690 Mpa |
| Bulk modulus of elasticity: | 250 GPa |
| Shearing modulus: | 140 Gpa |
|
Optical
Properties
|
|
| Transmittance: |  Click to enlarge |
| Optical Transmission Range, (80%): | 350-5500 |
| Refractive index: | 1.83
at 0.26 mm 1.76 at 0.63 mm 1.58 at 5.57 mm |
| Thermal Coefficient of Refractive Index: | bo=(0.88...1.28)
x 10 -5 bc= (0.99...1.39) x 10 -5 |
