Synthetic Diamonds

What is it ?

Synthetic diamonds are man-made materials that have the same chemical composition, crystal structure, and properties as natural diamonds. Diamond simulants are materials that look like diamonds but have different chemical compositions and physical properties.

Many companies have been successful at producing synthetic diamond suitable for industrial use. Today, most of the industrial diamond consumed is synthetic, with China being the world leader with a production of over 4 billion carats per year.

High-pressure and high-temperature (HPHT) method is the most widely used as it is comparatively low cost. In this method, there are three main press designs that are used to supply the pressure and temperature required to produce synthetic diamond – the belt press, the cubic press and the split-sphere (BARS) press. These presses can weigh hundreds of tons to produce a pressure of 5 GPa at 1500°C (2732°F).

The chemical vapor deposition (CVD) method is used to grow synthetic diamond from a hydrocarbon gas mixture. This method is preferred in laboratory research as it is simple and flexible to setup. The other advantages of this method are the possibility of growing synthetic diamonds over large areas and on different substrates, and the precise control over the chemical impurities. The CVD method does not require as much pressure as the HPHT method.

The ultrasound cavitation method is primarily used to manufacture micron-sized diamond crystals. Micron-sized diamond crystals can be created from a suspension of graphite in organic liquid at atmospheric pressure and room temperature using ultrasonic cavitation.

Properties of Synthetic Diamonds

The major consumers of industrial diamond are computer chip production,
construction, machinery manufacturing, mining services (drilling for mineral, natural gas,
and oil exploration), stone cutting and polishing, and transportation systems
(infrastructure and vehicles).

Mechanical Properties

+ Incredible hardness
+ Very low coefficient of friction
+ High precision

Optical Properties

The widest spectral band of any material,
extending from UV to far infrared
and the millimetre- wave microwave band.

Thermal Properties

The highest known resistance to thermal shock
The highest known thermal conductivity
Low thermal expansion

Electronic Properties

Very good electrical insulator properties
Can carry very low current even under high voltages

Acoustic Properties

Excellent acoustic properties allow unmatched
clear and transparent sound reproduction

Electrochemical Properties

Chemically and biologically inert
Can be used in extreme chemical,
physical, and radioactive
Possibility of efficient oxidation
of organicand inorganic compounds
Ozone production on a scale that is appropriate
for homes, hotels, and hospitals