NanoPak is NDP’s Thermally Stable Polycrystalline (TSP) product for high temperature wear applications. NanoPak is a composite structural ceramic consisting predominantly of synthetic micron diamond bonded together under very high pressures and temperatures with silicon carbide (SiC) to form a very hard, thermally stable solid body. NanoPak is available with a range of diamond distributions and bond derivatives to provide an optimised balance between wear and toughness.
In particular, the use of fine micron diamond in conjunction with coarser sizes reinforces the softer SiC binder phase, significantly reduces the mean free path of the diamond particles and maximises the diamond fill of the composite. It has been shown to significantly improve wear resistance , particularly in erosive and abrasive sliding wear applications.
In all other respects, the characteristics of NanoPak parallel those of other conventional TSP materials:
- It has an inert binder phase so that there are no chemical incompatibilities with other metals present
- It has a diamond content of 80-85 % by volume
- It is thermally stable up to 1200°C
- It can be manufactured in a variety of shapes and sizes to meet the exact requirements of the application
Due to its excellent thermal stability, NanoPak segments can be sintered directly into metal matrix composites, such as the tungsten carbide – cobalt bit bodies used for PDC bits.
Because of the presence of some free silicon in the matrix, NanoPak materials can be difficult to fix onto surfaces. For this reason, NDP has also developed a range of metallic coatings that can be applied to the segments to allow for brazing or “pseudo” welding onto surfaces.