In the production of ceramic grinding tools the following abrasives are used:
White aluminium oxide (over 99% Al2 O3), polycrystalline, cutting well and easily revealing cutting edges, heating the treated surface to a relatively small extent. It is used to treat different types of steel: most commonly carbon and alloy with the content of C> 0.5% and hardness above 62HRC.
- CrA chrome aluminium oxide, coloured pink due to a small amount of chromium oxide. it is relatively more resistant to chipping of the cutting edges and is used for machining various steels including the hardened ones.
- Brown aluminium oxide 95A (approx. 94.5% Al2 O3) used for initial and efficient processing of different types of steel: most commonly carbon steels C<0.5%; cast steels, malleable cast iron; non-ferrous metals.
- Grey-brown semi-precious aluminium oxide 97A (approx. 97.5% Al 2 O 3) with intermediate properties between aluminium oxides 99A and 95A. It is characterized by a lower content of titanium oxide than plain aluminium oxide. It is used for different types of steel: carbon steel and alloy steels with the content of C> 0.5% and hardness to 62HRC.
- Aluminium oxide CerPass-XTL (SG) (approx. 95% Al2 O3) having a light blue colour is a highly efficient abrasive, finely crystalline, particularly suitable for wet grinding. It is mainly used for various types of stainless steel and alloys of the titans, chromium and nickel.
- 99C green silicon carbide, which is used for machining high-speed steel and tool steel, cemented carbides, ceramics and plastics.
- 98C black silicon carbide, which is used for machining grey and hardened cast iron, cemented carbide, ferrous metals, plastics, leather and rubber.
An extremely resistant abrasive material used in the production is borazon (CBN). It is used primarily in grinding, where precision and smoothness of the machined surface are crucial. Due to its characteristics, CBN gives its users the opportunity to shorten the processing time and relatively lowers the temperature of grinding, which allows to minimize the risk of damage to the ground surface.
Borazon grinding wheels (CBN) are used for the treatment of:
- High-speed steels
- Tool steels
- Case-hardened steel
- Heat-resistant steel
- Stainless steels with hardness
HARDNESS OF THE GRINDING WHEELS
There are three basic degrees of the wheels hardness:
- Soft: I, J, K
- Medium: L, M, N
- Hard: O, P, R, S
Soft wheels are used for grinding large surfaces, where it is forbidden to produce high temperature abrasion. In contrast, the high-hardness grinding wheels are used for profiled grinding and using a coolant or wet grinding.
The abrasive tools produced are adjustable in hardness and structure, which means that per unit volume in each of the wheel the amount of the abrasive and the binder are indicated. In this way it is possible to adjust the parameters of abrasive tools produced to, sometimes specific, customer requirements.