CBN Abrasive: A Guide to Cubic Boron Nitride

Cubic boron nitride (CBN) is a superb abrasive material designed specifically for advanced wear-resistant characteristics. It is a comparatively recent material innovation which has been earmarked as one of the greatest technological advancements of all time for abrasives. But what makes CBN abrasives so useful in roughing applications?

What is Cubic Boron Nitride?

Cubic boron nitride, henceforth abbreviated to CBN, is a synthetic crystalline material that is second only to diamond in terms of hardness. It is structurally analogous to diamond too, with a complex cubic/sphalerite structure composed of interpenetrating face-centred cubic lattices.

Essentially, CBN abrasive grains are composed of short, covalent boron—nitrogen bonds which form extremely tight three-dimensional (3D) matrices. These structures are inherently resistant to abrasion, corrosion, and thermal deformation, which makes CBN abrasives ideal for grinding applications.

CBN Abrasives: Common Applications

Although marginally softer than diamond, CBN abrasives are relatively inert and boast exceptional thermal stability under intense working conditions. They will not react when lapping ferrous metals. Nor are they prone to oxidation when grinding steel alloys. These combined properties make CBN grains the abrasive of choice for high-performance grinding wheels tasked with cutting or roughing cast iron, nickel-based alloys, and a wide range of steel grades.

Types of CBN Grinding Wheels

• Metal bond CBN grinding wheels where a mesh of electroless nickel-coated particles are sintered directly on the wheel to yield an extremely robust tool.
• Resin bond wheels compose semi-blocky CBN abrasive grains with finely-tailored friability for non-ferrous grinding applications.
• Vitrified grinding wheels comprise synthetic bonding systems and either micron or mesh CBN grains, depending on the intended use.

Key Properties for CBN Abrasives

Despite the fact that CBN grains are a relatively recent addition to the fold of abrasive materials, a range of chemistries and forms already exist. When selecting CBN abrasives, you should consider the same basic parameters that you would with any intermediary grain for superabrasive applications. These include:

• Particle size distribution (PSD)
• Morphology
• Aspect ratio
• Toughness index (Ti)
• Purity
• Percentage coating by weight (if a metal coating is applied)

 CBN Abrasive Products from Saint-Gobain

Saint-Gobain Surface Conditioning is an industry leader in abrasive grain engineering, with decades of expertise producing precision solutions for grinding applications. We offer a highly selective range of CBN abrasive materials under five product lines: cBN B1 CS, KB, W and V. We also offer finely-tailored electroplated products with enhanced adhesive properties for longer-lasting cutting surfaces.

If you have any questions that we haven’t answered in this brief guide, refer to our FAQs on our individual product pages for deeper insights into their specifications and performance parameters. Or, if you would like to speak with a member of the team, simply contact us today.