CBN Abrasive Particles, Precision Engineering
Cubic boron nitride, CBN, is an important supermaterial within the Element Six family of abrasive particles. As the second hardest known material, with only diamond being superior, CBN is a complementary material to diamond abrasive particles. Consequently, it is used in those application areas where diamond is not suitable or where it offers specific benefits such as in the machining of ferrous materials.
As an abrasive material, CBN is characterised by high hardness, abrasion resistance, strength and resistance to thermal and chemical attack. In particular it is able to maintain its hardness advantages over a wide temperature range.
Element Six offers a wide range of uncoated and coated/cladded CBN abrasive particles. These products can be used with all found main bond types: resin, vitrified, electroplated and sintered metals.
Product Range
Uncoated products:
ABN200
This consists of black, friable, irregular shaped particles that is designed to have ‘free cutting’ fracture characteristics. Its strength, thermal stability and sharpness make it suitable to for a wide range of standard vitrified bond applications.
ABN300
Comprising clear amber-coloured, friable irregularly shaped particles, ABN300 offers similar strength to ABN200, with different morphology and fracture characteristics that is typically suitable for use in electroplated tools
ABN600
This is a black, crystalline, high strength particle with good thermal stability. Its ideal use is in sintered and electroplated metal bonds where the impacts loads on the abrasive particles are high. It is also advantageous in certain applications where a strong, blocky particles with a relatively negative rake angle is required.
ABN605
This offers similar characteristics to the ABN 600, black crystalline particles with high strength and thermal stability. It is designed perform well under high impact loads, and where a less angular particle shape is required. Available in coarse sizes between 30/35 and 50/60 US mesh, it is suitable for metal and electroplated bonds.
ABN700
This is an intermediate strength CBN particle with sharp fracturing characteristics with good thermal stability that make it suitable for vitrified bonds. ABN700 has been designed for strength and thermal stability between those of ABN200 and ABN800.
ABN800
This is a dark brown, angular, high strength particle with high thermal stability suitable for vitrified bonds applications. Its truncated tetrahedral morphology provides an angular particle shape and its overall properties make it suitable for the most demanding application areas.
Coated and clad product ranges:
For the products, the cladding is electroless or electrolytic (P) nickel, accounting for 60 % of the mass of the particle. The cladding improves particle retention (through its spiky form) and improves the dissipation of the heat from grinding operations, for example. Products available clad for use in resin bonds:
ABN 260 and ABN 260P
These are the clad versions of the ABN200 and through its combination of high particle strength and sharp cutting characteristics is idea for demanding high performance resin bond applications.
ABN760P is primarily designed for use in high performance resin bond tools, where the combination of intermediate strength for good metal removal rates and sharp cutting characteristics for free-cutting is required.
ABN860 which is the clad version of the ABN800 combines high particle strength with sharp cutting characteristics so making this product suitable for efficient use in demanding high performance resin bond applications
Metal bonds
ABN615 is the clad version of the ABN600 and is available coated for use in metal bonds. In this product the thin titanium coating chemically links to the CBN particle and simultaneously alloys with the metal matrix. This enhances particle retention in application, increasing particle protrusion, grinding rate and/or tool life.
Micron+ABN
This product consists of irregular shaped particles graded into discrete size ranges and is suitable for grinding, lapping and finishing of hard ferrous materials.
- Product Literature
- Applications
- Parameters
- Material Safety
More information on our CBN Abrasive Particles, Precision Engineering is available in our Product Brochures and Announcement Sheets:
Fine CBN abrasive particles offer high productivity compared to conventional abrasives when used for grinding, honing and fine finishing hardened ferrous and difficult-to-machine alloys. Some typical workpiece materials are:-
- Hardened carbon steels
- Alloy tool steels
- Bearing steels
- Cast irons
- Superalloys
- Hard stainless steels
Major application areas for fine CBN diamond abrasives are in tool and cutter grinding of high speed steels though other applications such as production grinding in the engineering, automotive and aerospace industries are now well-established.
ABN200 applications include:
- Grinding of HSS flutes in the tool and cutter industries
- Double disc grinding of piston rings
- Centreless grinding of rollers for bearings
- Surface grinding of mould and tool steels
ABN300 is typically used in electroplated tools and application areas include:
- High tolerance gear grinding
- Outer diameter roughing operations on crank and transmission shafts
ABN 605 Application areas include honing operations
ABN 700 Application areas include:
- Double disc grinding
- Outer diameter operations in the cam and crank industries
ABN800 application areas include:
- Outer diameter operations for cast irons and forged steels
- Inner diameter grinding of bearing rings
- Creep feed grinding of tool and die steels
Particle Strength
Average particle strength is one of the determinants used by the toolmaking industry for abrasive selection. ABN200 and ABN300 have similar particle strengths, but their crystal morphologies and fracture characteristics differ. Under impact loading, both products exhibit a controlled breakdown characteristic ensuring that a sharp cutting action is maintained. However, the fragments which break away from particles of ABN200 are smaller than those breaking away from ABN300.
ABN600 and ABN800 have similar particle strengths, but their crystal morphologies differ. In common with most CBN materials, ABN200, ABN300 and ABN600 exhibit some measurable and controlled reduction in strength when exposed to elevated temperatures. By contrast, ABN800 has a very high thermal stability and shows no significant reduction in impact strength after heating to a temperature of 1100°C.
Crystal Morphology
For many years Element Six has used a simple system of crystal identification to describe the morphology of diamond and CBN particles - the Morphology Index. This index describes the range of crystal forms which can be produced dependent upon the growth conditions prevailing during synthesis. The selected conditions influence the relative growth rates of the different crystal faces or planes, which determine the final morphology and shape. The final form influences both the physical and chemical properties of the particle, and hence its behaviour during use. The morphology of CBN is more complex than that of diamond. Diamond crystal morphologies range from pure cubic to octahedral, depending on the relative rates of growth of the main crystal faces, In the case of CBN, the crystal morphology can also range between these two extreme forms and, in addition, under suitably controlled synthesis conditions, tetrahedral forms can be produced. Element Six has selected four different domains in the morphology chart in which to produce its four ABN products. They each therefore exhibit differences in fracture mechanism and surface chemistry, in addition to the differences in other physical properties of, for example, impact strength at both low and elevated temperatures, colour and overall crystal shape.
Our product sheets contain all the relevant information covering the application and safe use of our products. You can download the information by clicking on the link below but if you would like more information about a particular issue please contact us: info@e6.com