John P. Dismukes

Economic Assessment of CVD Diamond Synthesis Technologies

Abstract Chemical Vapor Deposition (CVD) synthesis of diamond was discovered at almost the same time as the commercialization of the High Pressure - High Temperature (HPHT) synthesis of diamond grit. However, it took two decades to show feasibility of growing pure CVD diamond at practical rates. From about 1980 to the present, CVD diamond science and technology has undergone an explosive period of investigation, leading to the development of a number of CVD diamond techniques, including H-Atom-Plasma and Chemical Methods in the H-C, H-C-O and H-C-F systems. Because these CVD diamond technologies are either developmental or only recently in production, there are still numerous uncertainties in the eventual manufacturing costs attainable with CVD. To estimate CVD diamond manufacturing costs, and to compare them with those of commercial HPHT diamond synthesis, we employ a computer based Technical Cost Modeling (TCM) approach which has the flexibility to structure and evaluate model factories with a variety of unit processes representing the different CVD diamond synthesis techniques. A generic approach is first presented to calculate the cost of CVD diamond coatings, which allows future update of cost estimates by incorporating advances in equipment and plant size, process technology, and yield and deposition rate. The general case also provides a basis for assessing factors which influence the cost of depositing CVD diamond powder, or grit. Sensitivity analysis is then applied to the Microwave and Filament CVD methods to understand the dependence of CVD diamond costs upon growth rate, layer thickness, yield, and production volume. The polycrystalline CVD diamond X-ray window is an example of a high systems value commercial product already successful at small scale of manufacture. CVD diamond optical coatings and electronic components are potential specialty products which possess the capability of becoming commercially viable at low production volumes. At high volume manufacture, Microwave and Filament CVD diamond technologies appear economical for large area deposition of thin polycrystalline coatings for use in cutting tool inserts, at add-on costs below

Economic Assessment of HPHT Diamond Synthesis Technology

150/carat. With advances in technology, thick diamond coatings for cutting tool inserts and thermal management components could ultimately become available at add-on-costs below

Nanoporous ceramics with catalytic functionality

5/carat. Low process gas-to-diamond yield and high energy usage are the chief factors that limit the cost competitiveness of CVD diamond powder with HPHT diamond grit.

Method for fabricating fracture-resistant diamond and diamond composite articles

Abstract The High Pressure - High Temperature (HPHT) diamond synthesis technology, commercialized in the 1950s to manufacture diamond grit, represents the benchmark for many industrial cutting and wear applications, such as abrasives, cutting tools and wear resistant surfaces. Here we assess grit manufacturing cost and price trends, so as to better appreciate the technologys history, and to assess its future potential in view of the new CVD diamond synthesis. To estimate manufacturing costs of HPHT diamond grit, we have employed a unique computer based Technical Cost Modeling (TCM) approach, which provides a systematic basis for capturing individual cost elements for each unit operation in a model facility for diamond grit production. Sensitivity analysis was applied to understand the dependence of cost upon equipment size, yield, plant size and annual throughput for diamond grit and compacts. To estimate price trends, published information from the U.S. government was employed. Technology for producing synthetic diamond grit has progressed significantly over the past 35 years, resulting in scale driven decreases in production costs(1989

Trends and market perspectives for CVD diamond

) from about

Fullerene-polymer compositions

4,40 in 1963 to approximately

Chemical Synthesis of Microporous Nonoxide Ceramics from Polysilazanes

0.14 in 1989. Over the same period, worldwide grit synthesis has increased from about 5 million carats in 1963 to about 340 million carats in 1989. In a characteristic experience curve behavior often observed as industrial markets grow and mature, synthetic grit prices (1989

Synthesis of microporous ceramics

) followed production costs, decreasing from about

Pyrolysis of ceramic precursors to nanoporous ceramics

11.50/carat in 1963 to about

Synthesis of preceramic polymer-stabilized metal colloids and their conversion to microporous ceramics

0.74/carat in 1989. For the year 2000, our cost model projects that HPHT grit costs could fall below