Sapphire Crystal

HT sapphire crystal is synthetic hexagonal structure crystal growing by high-temperature melting and crystallizing of high-purity alumina (Al2O3) with a purity over 99.999% in a crystal growth furnace. Sapphire crystal has remarkable characteristics of high sound velocity,heat resisting, corrosion resisting, high hardness, high light transmittance and extremely high melting point(2050℃). So sapphire crystal has been widely used for optical components, optoelectronics components, IR facilities, high-strength laser films and photomask.

DESCRIPTION

HT provides both HEM sapphire crystal and KY sapphire material with several advantages:

-Sapphire boules’s shape is regular.

-Sapphire quality is stable.

-Sapphire product utilization is high.

HT sapphire crystal properties

Mechanical Properties	-	Optical Properties	-
Density	3.97g/cm³	UV	>70%
Vickers hardness	22GPa	Visible ~ near mid-infrared	>87%
Tensile strength	413.79MPa	Refractive index	1.83@255nm
			1.76@630nm
			1.58@5570nm
Compressive strength	2068.97MPa	-	-
Young's Modulus	74×10⁶psi	-	-
Poisson's Ratio	0.28	-	-

Electrical Properties	-	Thermal properties	-
Conductivity	@25℃>1018ohm cm @500℃>1012ohm cm	Melting Point	2050℃
Dielectric Constant	(⊥)C 9.3 (KHz-I GHz, 25°)	Thermal Conductivity	32W/Mk (@258℃)
Dielectric Constant	(∥)C 11.5 (KHz-I GHz, 25°)	Thermal Conductivity	32W/Mk (@258℃)
Dielectric Strength	480,000v/cm	Specific Heat	1.99 J/cm³°C

Item	Parameter	Testing Equipment
EPD	<1000/cm²	Leatz (Polarizing microscope)
(Rocking Curve)FWHM	<15”	X'TRA
Purity	>99.999%	GDMS

HT Sapphire Crystal’s Orientation Difference

Sapphire Crystal Orientation	Hardness (kg/mm2)	Flexural Strength (MPa)	Dielectric Constant	Different Orientation Performance
C	2200	350	11.5	Isomorphism
A	1800	500	9.3	Isomerism
M	1800	500	9.3	Isomerism

HT Sapphire Crystal Sizes

	Weight	Diameter	Height	Crystal orientation
115kg grades	100-120kg	380-400mm	210-260mm	A orientation
130kg grades	120-140kg	380-400mm	250-300mm	A orientation
165kg grades	140-170kg	440-460mm	260-300mm	A orientation
200kg grades	200-260kg	500-520mm	280-300mm	A orientation