Man-Made Diamonds

Hollomon s ethos, combined with his ferocious energy and determination, and his sustained determination to recruit only the best researchers to join his group, over the next 15 years led to a sequence of remarkable innovations related to materials, including man-made diamond, high-quality thermal insulation, a vacuum circuit-breaker, products based on etched particle tracks in irradiated solids, polycarbonate plastic and, particularly, the Lucalox alumina envelope for a metal-vapour lamp. (Of course many managers besides Hollomon were involved.) A brilliant, detailed account of these innovations and the arrangements that made them possible was later written by Guy Suits and his successor as director, Arthur Bueche (Suits and Bueche 1967). Some of these specific episodes will feature later in this book, but it helps to reinforce the points made here about Hollomon s coneeption of broad research on materials if I point out that the invention of translucent alumina tubes for lamps was... 

By February 15, 1955, diamonds had been produced in about 100 separate runs in the General Electric Research Laboratory. On this date a press conference was held and the fact that diamonds had finally been made by man was announced to the world. However, details concerning the synthesis were not released. On October 22, 1957, the company announced that diamond production had successfully been carried through the pilot plant stage—more than 100,000 carats (carat = 0.200 g) having been produced up to that time. Thus, less than three years following the successful conclusion of a 100-plus years search for a method to convert ordinary black carbon into diamond, man-made diamonds became a commercial product. Details of apparatus and methods of synthesis were finally released in the fall of 1959. 

Yarnell, A. The many facets of man-made diamonds. Chem. Eng. News 2004, 82 (5), 26. 

Bundy, F.P., Hall, H.T., Strong, H.M., and Wentorf, R.H. (1955) Man-made diamonds, Nature 176, 51. First description of diamond synthesis. Hazen (1999) indicates that synthetic diamonds may have been made prior to this publication from GE. 

Reports on man-made diamond obtained by HPHT synthesis were first published in 1955 by General Electric [4]. Usually, metals able to dissolve carbon under HPHT conditions are used as catalysts and increase growth rates. Diamond crystals of several millimeters in size can be obtained in this way, but usually small grains for abrasives are produced. Direct conversion of graphite to diamond without catalyst in HPHT apparatus is possible, but uneconomical for industrial application. Direct transformation can be done by the detonation method and produces nanosized powders of diamond and diamond-like carbon [5]. 

A synthetic or man-made diamond material is now available which is extremely tough with a hardness approaching that of natural diamond. A layer of this synthetic diamond material is bonded to a tough shock-resisting base of cemented carbide for use in the form of tips. The range of application is on non-ferrous metals such as aluminium alloys, magnesium alloys, copper, brass, bronze and zinc alloys and non-metallic materials such as ceramics, porcelain and plastics. This material will also machine fully sintered tungsten carbide. 

There are two types of diamonds, synthetic and natural. Synthetic diamonds are man made and are used in PDC STRATAPAX type bit designs. STRATAPAX PDC bits are best suited for extremely soft formations. The cutting edge of synthetic diamonds are round, half-moon shaped or pointed. 

Diamond, J. M., W. Bower, and D. Gruber. 1993. Use of man-made impoundment in mitigating acid mine drainage in the North Branch Potomac River. Environ. Management 17 225-238. 

Living plants or other subject matter were considered not patentable uner the general patent law until recently. In accordance with the 1980 decision of the Supreme Court in Diamond v. Chakrabarty 447 U.S. 303 (1980), the general patent law does not exclude the patenting of man-made living matter. 

As mentioned above, only the minerals diamond and natural graphite are found in nature. All other carbon products are man-made and derive from carbonaceous precursors. These synthetic products eu e manufactured by a number of processes summarized inTable 1.2. Each process will be reviewed in the relevant chapters. 

And first we hear it in every mans mouth, and in many good Authors we reade it. That a Diamond, which is the hardest of stones, and not yielding unto Steele, Emery, or any thing, but its own powder, is yet made soft, or broke by the bloud of a Goat ... 

He discovered wonderful stories, also, about jewels. According to the great alchemist, Pierre de Boniface, the diamond rendered a man invisible, and the agate of India made him eloquent. The cornelian appeased anger, and the... 

---