Why Switch To A Vitrified Superabrasive Grinding Wheel?

How a grinding wheel performs is dictated as much by the bond as the abrasive. Superabrasives, which can be either diamond or cubic boron nitride (CBN) have four types of bond: metal, plated, resin and vitrified. Of these, vitrified may be the least well-known, yet it’s attracting attention, thanks to the improved performance and lower costs that it offers.

WHAT IS A VITRIFIED WHEEL?

In a vitrified wheel superabrasive grit is mixed with a type of glass or ceramic and then pressed before firing in a kiln. This creates a porous, glass-like structure that holds the grit in a rigid matrix.

Unlike a plated wheel where the abrasive is just a single layer, a vitrified wheel can have considerable depth. This means the wheel can wear and go through repeated dressing. Wear rates are very low as the vitrified bonds must fracture to release worn grit and expose fresh edges. It’s also possible to put a form into the wheel to allow grinding of complex profiles, (although this does complicate dressing.)

BENEFITS OF VITRIFIED DIAMOND AND CBN WHEELS

The open, porous structure ensures the grit stands proud of the bond surface, creating a wheel that’s described as ‘free cutting.’ This means good space for chip clearance, which:

  • increases material removal rate

  • lessens dressing frequency

  • reduces wear

  • carries coolant through the grinding zone

  • lowers grinding forces, thus creating less heat and less work piece damage

As an additional benefit, these last five points result in lower temperatures at the interface and reduced risk of workpiece burning in metals and less microcracking in ceramic and hard materials.

Lower temperatures help maintain control over final size, as does the very rigid nature of the wheel. With minimal wheel deflection due to grinding forces and low thermal growth very high tolerances can be maintained throughout a production run.

APPLICATIONS

High volume production are ideal applications for vitrified grinding wheels. Low wear rates, combined with a free-cutting nature and ‘dressability’ mean very high material removal rates and less downtime for wheel changes.

Vitrified cubic boron nitride grinding wheels are preferred for grinding hard ferrous workpieces like crankshafts and camshafts as well as tool steels. Vitrified diamond grinding wheels are good in non-ferrous applications such as shaping ceramics and carbides.

THE HIGH-VOLUME WHEEL

Of the four main bond types, the vitrified wheel is best suited for high volume, extended production run applications. The rigid, porous structure delivers high material removal rates and extended life, helping lower manufacturing costs.

Call the engineers at CDT at 800-443-6629 to talk over your specific application and determine if a custom vitrified grinding wheel would benefit your manufacturing process.

ProductsStacy ViggianoVitrified Bond Grinding Tools