Buy Online: The properties of Cubic Boron Nitride
Cubic Boron Nitride or CBN is one form of a synthetic material developed in the early 19th century. As boron and nitrogen are elements that are close neighbours to carbon in the periodic table - it is not surprising therefore that boron nitride and carbon exhibit similarity in their crystal structure. In the same way that carbon exists as graphite and diamond, boron nitride can be synthesised in hexagonal and cubic forms.
Thus CBN, the cubic form has the following properties:
- It is the second hardest material known, second only to diamond
- High thermal conductivity
- Excellent wear resistance
- Good chemical inertness
At Element Six, we have developed a range of CBN materials called polycrystalline cubic boron nitride, PCBN, which are used for cutting tools and abrasive components particularly for use with low carbon ferrous metals. In this application, the tools behave in a similar manner to polycrystalline diamond tools but can be used on iron and low carbon alloys without risk of reaction because CBN is chemically inert.
PCBN is made by sintering CBN particles ( between 1 to 10 microns in size) with a variety of different ceramics using the high pressure, high temperature principle that is used to make synthetic diamond. The result is a solid material that is used for cutting tools generally for rough and finishing machining of certain steels, grey cast iron and hard cast irons and or finish turning or sintered irons and powder metallurgy components. Essentially, any ferrous workpiece material, which is either abrasive or hard, is a potential application area for PCBN cutting tools.
Individual grades of PCBN are engineered to provide different property combinations. These are dictated by the size of the CBN particles, the percentage of CBN within the sintered composite, the ceramic binder phases and the manufacturing method.