Diamond Synthesis: The Russian Connection

Abstract

Several 40-year anniversaries of the modern area of the synthesis of diamond at high pressures and temperatures (HPHT) have come and gone. If you are a proponent of the Norton Company, this first synthesis would be somewhere between 1948 and 1950. ASEA's Feb. 15, 1953, accomplishment was noted at an international meeting in 1993 on high pressure (AIRAPT) with a small session that included papers by ASEA and General Electric (GE) representatives. The GE success in the Hall experiment of Dec. 16, 1954 (announced in February 1955), was marked only in the personal memories of the remaining members of that diamond team. DeBeers recognizes the ASEA date, but if it celebrates the 40th anniversary of its own in-house accomplishment, it will do so late in 1998; the Russians will do so on or about the year 2000. In any case, the basic, muchcopied GE HPHT process is repeated thousands of times each day at sites all over the world (Figure 1) to make a product that has replaced 90% of natural diamond as an abrasive and has given to technology new superhard products in forms unavailable from the earth (Figure 2). All manufacturers are in fierce competition for a total business that probably is in the range of $1 billion per year, and engineers spend their time primarily in finer tuning for faster growth, greater yields, lower costs, and higher quality crystals. The HPHT process seems to have survived the threat of the low-pressure chemical vapor deposition (CVD) process with respect to abrasive grain and gem-quality stones. However, the low-pressure process has some unique capabilities that obviously cannot be achieved by HPHT, and the product is finding niches in specialized applications (Figures 3 and 4).