Xindeco Ltd.

ARTIFICIAL CORUNDUM MATERIAL


Uses of Artificial Sapphire
The synthetic corundum is an ideal monocrystal material. It has advantages of heat-resisting and anti-radiation besides its good mechanical, electrical and optical properties, and therefore are widely used for jewel bearings in instruments and meters and for wear-resisting components in precision machinery. It is also suitable to make orifice jewels, that are useful for synthetic fibre, dye and food industries, infrared-ray-transmitting windows, bases for IGFET (insulated-gate field- effect-transistor), output windows for high power microwave tube, substrates for IC (integrated circuit), etc.

Uses of Synthetic Ruby

Ruby can be used for orifice jewels, insulators and laser working-material, as well as for jewel bearings in instruments and timepieces and for wear-resisting parts in precision machines.

Uses of Natural Agate

Agate can be used for bearings in instruments, knife-edge of balances. Also it can be manufactured as ornament.

Specifications

1. The angle between 60o-75o for sapphire; growth and optical axes: 55o-65o for ruby.
2. Corundum should be strictly inspected according to the standard concerned; any blisters, impurity and cracks within the material are not allowed.
3. The sapphire boule have the length from 40-60mm, and the diameter from 18-23

Hole ring stoneJewel packing ring
Sapphire insulatorJewel thread guide
Agate bearing with conical recessPen point
Jewel measuring-headCorundum contact tip
Corundum ballY-shape molybdum wire positioner
TECHNICAL DATA OF CORUNDUM

Chemical formula a-Al2O3 monocrystal
Hardness Mohs' scale number, 9
Microhardness, HV>=5691 N/mm2
Melting-point 2030oC
Chemical resistance Not attacked by acids or by NaOH at normal temperature.
Attacked by HF at temperature of 300oC
Friction coefficient Coefficient of dry friction on steel, 0.14
Compressive strength 2.1 GPa
Tensile strength 0.19 GPa
Resistivity 1X1016/cm(25oC); 1X1011/cm(500oC); 1X106/cm(100oC)
Dielectric Constant 8.5~11(300KHz~1GHz)
Breakdown field strength 48000V/cm
Coefficient of expansion c: 6.5X10-6oC-1(50oC); 9X10-6oC-1(1000oC)
c: 3X10-6oC-1(50oC); 8.3X10-6oC-1(1000oC)
Thermal conductivity 33w/MooC(20oC); 25w/MooC(100oC); 8.4w/MooC(700oC)
Index of refraction c:1.769; c: 1.760 (=5893)
Transmission of infrared rays Larger than 85%
Anti-radiation property After the accumulated radiation of 1012 protons/cm2, no change in transmissivity below 3000

1. Olive hole ring stone with one recess
Applicated in precision timers, automatic recorders, precision measuring tools and other instruments as cylinder supports.
D: 1.2-3.2mm; H; 0.30-1.2mm; d:0.20-1.2mm.

2. End Stone
Applicated in varieties of precision measuring tools, hydralicy76 gauges and other instruments and meters as end supports in their moving mechanism.
D: 1.0mm-5.omm.; H: 0.25-0.50mm.

3. Jewel with spherical recess
Applicated in the moving mechanisms of the electrical in- struments and meters, heat engineering meters and single- phase and three-phase watt-hour meters.
D: 1.8-5.0mm; H:1.2-3.0mm; h:0.30-0.50mm; R:0.65-3.00mm.

4. Agate bearing with conical recess
Applicated in the moving mechanisms of electrical, heat en- gineering, aviation, navigation and meteorological instruments and meters.
D: 1.0-2.5mm; H:0.8-2.5mm; h:0.30-0.6mm.

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