PCD (polycrystalline diamond)
Element Six polycrystalline diamond (PCD) is used in tools that provide the end-user with unsurpassed levels of productivity and workpiece quality.
Element Six provides a wide range of polycrystalline diamond (PCD) products to meet the demands of the precision cutting, oil & gas and hardrock mining industries.
PCD consists of micron-sized synthetic diamond powders bonded together by sintering at high pressures and temperatures.
Monocrystalline diamond exhibits different properties on different crystallographic planes in different crystallographic directions, whereas the polycrystalline form is 'isotropic' - exhibiting uniform properties in all directions.
The varying orientation of the constituent micron-sized synthetic diamond grains also provides a greater resistance to cleavage and is therefore, a stronger material.
PCD is produced on a cemented carbide substrate, so as to provide a source of 'solvent metal catalyst' to aide sintering, typically cobalt. Under extreme pressures and temperatures, the cobalt from the cemented carbide substrate infiltrates through the layer of micron synthetic diamond powder, causing neighbouring grains to grow together. Not only does the small residue of cobalt provide significant toughening, it also renders the material electrically conductive. As such, PCD may be electric-discharge machined - a critical attribute for the hardest known material. The integrally bonded carbide substrate also renders the composite brazeable, another critical attribute given that the major part of a cutting tool or drill bit is used solely for clamping, with the PCD material only located where it is used for cutting.
PCD discs for cutting applications
Every tool material must combine sufficient toughness with wear resistance. However, features with increased toughness will invariably have lower wear resistance. As a result, materials must be engineered to meet the demands of specific applications. In the case of PCD, the properties of the composite are engineered partly by modifying the size of the constituent synthetic diamond grains. As the grain size increases, so too does the wear resistance, albeit at the expense of strength. By reducing the grain size to one micron or less, the wear resistance and strength may both be increased beyond what is possible with slightly coarser materials and this, for example is exploited in the grade CMX850. Finer grain size materials are easier to mechanically grind and electric-discharge machine, and also provide a better workpiece surface finish in precision machining applications. For example, the grade CTM302 exhibits the highest wear resistance but due to a proprietary coarse-to-fine multi-modal grain size distribution, does not present the drawbacks of conventional coarse grain materials.
The benefits of Element Six PCD are appreciated by the majority of tooling companies around the world. In consultation with our expert engineering team, customers can select from the widest possible range of superhard materials for drilling and defined-edge cutting tools. These tools provide the end-user with unsurpassed levels of productivity and workpiece quality. Our processes and materials are subject to exacting control and assurance procedures, and our products are distributed with industry-leading service levels.
The Element Six polycrystalline diamond product range includes:
• PCD precision cutting tool materials
• Polycrystalline diamond compact (PDC) cutters for oil & gas
• Polycrystalline diamond compact (PDC) cutters for hardrock mining
• CVD (chemical vapour deposition) diamond grades, CDM and CDE.