Spinel (MgAl2O4)

Spinel crystal is fabricated by sintering and HIP in (hot isostatic pressure) techniques from high pure ultrafine spinel powder, is non-birefingence. It has excellent mechanical and thermal properties, high abrasion and erosion resistance as well. The spinel material is particularly useful in a wide variety of fields such as optical, electronic and structural applications.

Spinel crystal has high transmittance in the ultraviolet, visible and infrared wavelength regions as sapphire and quartz glass. Spinel is nearly as hard as sapphire, however it is much cheaper than sapphire. Now large size spinel is also a kind of good substitute material for quartz glass which has lower strength and thermal conductivity, and is easier to be corroded by acid and alkli.

Application

--Substrate of luminous faceplate of CRT, Polarimeter for LED. 
--Missile domes, a covering for a tank port, a submarine port, armor etc.
--A valve flap, valve seat, a water-jet cutting flow-shaper, a nozzle for process  fluids.
--Container for nuclear waste, components in a high speed printer and optical   computers.
--High-pressure arc lamp and lens, pressure vessel sight glass, furnace sight glass
--Watch crystal, safety goggles.

Main properties of spinel
Density
3.58 g/cm3
Moh Hardness
8.5 Mohs
Young's modulus
190GPa
Melting point
2135℃
Knoop hardness 1350Kg/mm2
Flexural strength
179MPa
Thermal conducitivity 15 W/m·K
Thermal expansion 7.3×10-6/℃
Transmission ( 0.2 - 6.5μm)                    
≥ 85%
Transmission range
0.17 - 5.5μm
Absorption coefficient
0.3×10-3/cm at 2.4μm