Introduction

As an element of extraordinary hardness, toughness and resistance to abrasion, diamond has been given employment in many industrial operations, either as a rectifier and stone turner, powder or agglomerated with other products, metallic or polymer such as grinding wheel.

Due to high demand that the diamond was after the second world war, it had to start thinking about making it, now becoming a typical laboratory, with the general designation of superabrasive.

Globally and in Western markets, the principles of this manufacture were designed in South Africa by De Beers and in the United States by General Electric.

Diamond synthesis

The diamond is synthesized by accelerating the process of Nature.

The natural diamond creation process begins with sedimentation of organic material. The pressure that the earth exerts and the high temperatures that prevail in its interior gradually transform these sediments, changing them first into carbon, and then to graphite, the penultimate stage before becoming diamond. As the pressure and temperature become even more intense, the graphite changes its crystalline structure to transform into diamond.

Diamond synthesis in laboratories begins with graphite. This is subjected to high pressure and temperature to produce a reaction from which small crystals are obtained. In early trials, some of the crystals oxidised in the presence of oxygen, while others remained unaltered. These were subjected to characterisation tests that included both crystallographic analysis, in which their octahedral structure was established, and refraction tests, in which results equivalent to natural diamond were obtained. The synthesised crystals were, therefore, identified as diamonds. The diamond powder obtained was stronger than natural diamond, and had a better geometric formation.

Classification by grain size

Before using this diamond powder, it is first necessary to classify it by grain size in order to be able to use it to produce the different finish grades required on machined parts. This selection is performed by screening. Currently, two mesh scales are used – FEPA and US Standard Mesh (the less precise DIN 848 standard has now become obsolete).

The unit of weight used in marketing diamond is the carat (ct), which is equivalent to 0.200 g, and, contrary to popular belief, is not a measure of diamond quality; it is exclusively a measure of weight..

MAIN INDUSTRIAL CONSUMERS OF DIAMOND

Industrial consumers of diamond are innumerable. Nevertheless, it is worth highlighting the following sectors as regular consumers of diamond products.