Machining/Grinding Sapphire

CiDRA® Precision Services, LLC has years of experience manufacturing micron level tolerance products from Sapphire. We leverage our in-depth dicing, drilling, milling, grinding, and polishing capability to manufacture the highest quality Sapphire products. For those applications with exacting optical requirements, CiDRA® Precision Services, LLC has the ability to clean, polish, and apply coatings.

Whether you need prototypes or volume production, CiDRA® Precision Services, LLC is here to help. Please contact us to discuss your applications.

About Sapphire

Sapphire Crystal Orientation Explanation

Synthetic Sapphire (Al2O3) is a visibly clear crystalline form of Alumina Oxide that is manufactured in large crystal boules.  All crystalline planes are defined relative to the C-axis (the basal plane) since this is the plane of physical and optical symmetry.  There are three A-planes, all of which are perpendicular to the C-plane, as well as R-planes and N-planes located at 57.6 and 51 degrees relative to the C-plane.  For simplicity, the drawing shows only the C and R planes.  Sapphire’s remarkable properties, including its high use temperature, hardness, optical clarity, flexural strength, and chemical resistance make it an increasingly popular material choice.  Given its crystalline form, many key material properties are anisotropic.  Engineers must be cognizant of the crystalline orientation when designing thermomechanical or optical components.    For example, the strength, hardness and most thermal properties vary considerably depending on the crystal orientation.                                                                

Sapphire Applications

  • Barcode scanner windows
  • Flow separators
  • Harsh environment optics
  • Heater substrates
  • Micro-bushings
  • Optical concentrator arrays
  • Optical wedge for a spectroscopic diagnostic instrument

Sapphire Properties

 

Units

Perpendicular to
the C-axis

Parallel to
the C -axis
Melting Point C 2050 2050
Max Use Temperature in Air C 2000 2000
Max Use Temperature
(Non-oxidizing)		 C 2000 2000
Thermal Shock (Quenching) C 200 200
Thermal Conductivity W/(m K) 23 - 40 26 - 40
Specific Heat  J/(K kg)
Coefficient of Thermal Expansion 1/C (x10^-6) 4.3 - 5.7 5.3 - 6.7
Color Transparent Transparent
Moh Hardness 9 9
Knoop Hardness kg/mm^2 1900-2200 1525-1800
Density g/cm^3 3.97 3.97
Porosity % of nominal 0 0
Compressive Strength MPa 2000-2940 2000-2940
Tensile Strength MPa 250 - 400
Flexural Strength MPa 1540 1035
Fracture Toughness (KIC) MPa m^1/2 1.9 1.89
Young's Modulus GPa 435-490 435-490
Poisson's ratio 0.27 - 0.3 0.27 - 0.3
Dielectric Strength kv/cm 48 48
Dielectric Constant (@1MHz) 9.3 11.5
Dielectric Loss Tangent 0.00003 0.000086
Resistivity ohm cm 5x10^18 2x10^19
Usable Transmission Range um 0.18 - 5.5 0.18 - 5.5
Refractive Index 1.768 1.760
The information provided in this table is for room temperature only, and is a compilation of publicly available data.  This information is provided for comparison purposes only, and is not intended to be warrantable.   Further, CiDRA® Precision Services, LLC disclaims any and all liability from errors, inaccuracies, or omissions.

 

Please contact us if you would like to discuss your Sapphire dicing, drilling, milling, grinding, polishing or any other machining applications.