The synthesized diamonds microstructure consolidation review

Abstract

Excellent mechanical, optical and thermal properties of diamonds are the advantages for which they are used in many areas and thus in the industrial as well. Considering that natural diamonds are rare and expensive, in order to overcome that, production of synthesized diamonds is a good solution. Hence, investigation of alternative producing methods led to discovery of commercially available chemical vapor deposition – CVD method. Using this method led to creation of microcrystalline diamond (MCD) with grain size larger than 100 nm. Because of some disadvantages of this synthesized diamond, new nanocrystalline (NCD) and ultra-nanocrystalline (UNCD) diamond materials were developed, with average size of grains ranging 5-100 nm and 3-5 nm, respectively. Reactor geometry, filament setup and gas phase conditions are also very important parameters for diamonds growth on silicon wafers, in addition to the mixture composition and pressure of applied gases. The goal of the paper is to present the relation of microstructure and diverse consolidation methods.