Synthetic diamond is used as a super abrasive in many industries from electronics to medical applications. These industries as well as others require cleanliness of the base product as paramount to a quality end product. One should understand some basic facts about synthetic diamond in order to grasp a better understanding of its abrasive application within the industrial sector. The following is a rudimentary narrative of the synthetic diamond synthesis process.

SYNTHETIC DIAMOND
In synthetic and natural diamond, impurities exist and are known as inclusions. They appear as dark spots, dispersed clouds, or opaque sections and are composed of many basic elements, such as hydrogen, nitrogen, oxygen, boron, magnesium, aluminum, silica, calcium, and other trace elements. Impurities that occur in synthetic diamonds are elements resulting from other metal catalysts used in production. Main catalysts are a combination of nickel, iron, and cobalt. Other impurities in synthetic diamonds are mainly from the high temperature, high-pressure (1,800 °C at 25–30 GPa) reaction chamber and post-processing.

Elements that are commonly monitored in synthetic diamond are aluminum, calcium, cadmium, cobalt, chrome, copper, iron, potassium, magnesium, manganese, sodium, nickel, silica, tantalum, vanadium, zirconium, zinc, and boron. Each of these elements play a role in the end use of the synthetic diamond and the quantity of impurities allowed — dependent on the intended end use. It should be noted, however, that the intended use is as critical as the materials that are being used in part of the overall manufacturing process. In many cases, the base material — synthetic diamond —can cause downstream processing problems for manufacturers. In simplistic terms, it is never goodto eat from a dirty plate.

Let us look at some of the reasons why the purity of a diamond surface isimportant.

CLEANED MESH OR MICRON DIAMOND
The need for surface-cleaned mesh or micron diamond is paramount to post-processing and for final products. The reasons for this can briefly be described as follows. Surfaces that contain certain levels of iron or other magnetic metal impurities can create problems in a nickel or copper-electroplating operation. Synthetic diamond containing too much iron will make it magnetic, which in turn will result in the diamond attaching to itself instead of to the plating chemical. The final result is the formation of clusters or agglomerates that decrease yields or cause an oversize condition on the final product. Bothare undesirable.

Diamond that contains too much of a calcium impurity will leave calcium deposits in a lapping operation that will be difficult to remove. The deposit may require an additional cleaning removal step — resulting in unnecessary cost increases. Diamond that contains too much manganese will cause computer read-write heads to depolarize pole tips in a lapping operation,rendering them useless.

Other synthetic diamond particles that are based on surface attraction forces from upstream processing can easily adhere to one another. This adherence can form agglomerates that can be connected by a network of interconnected pores or surface ions. Agglomerates will create processing problems if they are used in suspensions because they distort the distribution of particles and create unwanted artifacts as scratches on polished surfaces or voids in solid pieces. A medical prosthesis, such as a hip ball, needs to be a solid piece. Tiny voids created by these agglomerates can cause stress fractures that can lead to hip replacement failures. There are numerous other examples where control-of-surface impurities are necessaryfor proper control of a process or product quality.