PolyDie is NDP’s polycrystalline diamond (PCD) blank for wire-drawing applications. Polycrystalline diamond has long been used for the manufacture of wire drawing dies. The die blank is produced by high temperature, high pressure sintering of micron-sized diamonds to produce a solid disc of diamond within a supportive tungsten carbide ring. The polycrystalline nature of the diamond enhances its wear resistance and, unlike natural diamond, there is no preferred direction of wear or cleavage plane and, as a result of the production process, the material is exceptionally tough.
The polycrystalline diamond is available in a range of grain sizes from 3 micron to 50 micron, depending on the application requirements. A finer diamond grain will allow a higher quality polish to be achieved during die manufacture and hence better surface finish on the drawn wire. In applications where surface finish is not the main criterion, coarser diamond grain structures will extend the die life.
The die blanks can be supplied with or without the tungsten carbide support ring. If unsupported, the blanks can have a cross-section that is either circular or hexagonal.
Supported die blanks are available up to 26.8 mm diameter with a diamond core of 15 mm diameter and 15 mm deep; unsupported circular die blanks have a maximum diamond diameter of 16 mm with a 12 mm depth. The unsupported hexagonal blanks have a maximum diamond width of 5.2 mm with a 3.5 mm depth.