Vit-CBN abrasive tools have been used successfully for around 25 years and with a steadily growing share of the market. The key to the success of this by now most important bond system for CBN is in the outstanding abrasive properties of these largely porous structures, its controlled receptiveness to contouring and dressing and the high stock-removal volumes which its good wear properties can achieve.
Meister has developed all of the ceramic bond systems for CBN and diamond in-house since the 1980's, a long tradition that will ensure its further development and worldwide technological leadership going forward.
The structure of the vitrified abrasive wheel can be classically characterised in a ternary system by the following elements:
- the abrasive (or its chemical and physical properties)
- the bond
- the resulting microstructure
The available grades of CBN crystals offer a wide range of cutting properties and are selected for specific applications.
Vitrified bonds are usually made from frits, feldspar, kaolin and different clays. The vitrified bonds mostly contain the following cations: Al3+, Fe 3+,Ti4+, Ca2+, Mg2+, K+ and Na+ and less commonly, Li+. Modern bond systems are lead-free for health and applications reasons.
Their chemical and physical properties are determined ultimately by the combination of raw materials, the grit sizes that are used and the firing cycle, i.e. vitrification.
The microstructure is a function of the relative proportions of the abrasive grits (usually with a secondary grit in the case of CBN/diamond), bond content and residual pore volume, and is an essential precondition for an efficient tool.
The HPB bond and HPC technology are current further developments of vitrified bonding technology.