ASME-Landmark:GE's Ultra High Pressure Apparatus for the Production of Diamonds


In 1941, General Electric (GE) made an agreement with Norton and Carborundum to develop diamond synthesis. And while these companies were able to heat carbon to about 3,000 C under a pressure of 3.5 gigapascals (510,000 psi) for a few seconds, World War II soon interrupted the project. But it was resumed at 1951 at GE's Schenectady laboratories with a high-pressure diamond group consisting of Francis P. Bundy, H.M. Strong, and Tracy Hall, among others.

The GE team used tungsten carbide anvils within a hydraulic press to squeeze the carbonaceous sample held in a catlinite container, with the finished grit then being squeezed out of the container into a basket. Hall achieved the first commercially successful synthesis of a diamond on December 16, 1954, thanks to his breakthrough of using a "belt" press, which was capable of producing pressures above 10 gigapascals (1,500,000 psi) and temperatures above 2000 C. The press used a prophyllite container in which graphic was dissolved within molten nickel, cobalt, or iron, these metals acting as a solvent-catalyst that dissolved carbon and accelerated its conversion into diamond.

These diamonds were found to have the same crystal structure, composition, and characteristics as naturally-occurring diamonds, though the first synthetic diamonds were considerably smaller. Diamonds of up to one-tenth of a carat were, however, ideal for industrial applications.

This process became the basis of industrial-diamond production, demonstrating the fundamentals of producing and containing very high pressures, as used in all comparable apparatus that followed. See ASME website for more information