Wheel performance and the efficiency of the grinding operation are determined to a large extent by the correct choice and the careful manufacture of the bond, as well as by the quality of the abrasive and the grit size. To account for the virtually infinite variety of different grinding processes and their ever-increasing demands, we continuously optimize and supplement our range of bonds. Depending on the conditions of use, DIAMETAL grinding tools are used with the following bond types:
|Metal-vitrified bonds||MV (VC / V2)|
The bond properties are essentially characterized by the bond agent used, as shown by the table below:
Basic properties of the bond systems
The bond characteristics can also be varied by adding different fillers, grinding grit and bond agents. Essentially, their purpose is:
|Supporting fillers:||Supporting the grinding grits and anti-wear protection|
|Metallic fillers:||Thermal leak-off and better grit retention|
|Reducing the friction heat and better chip removal|
|Poren-forming fillers:||Coolant transport and reducing the contact surface|
Today, with the wide variety of combination options involving grinding grit, fillers, concentration and substrate material, there is always the right kind of grinding tool to meet the requirements of any modern grinding process. Thanks to our wealth of experience combined with ongoing developments, our product offering provides an unmatched variety of different bonds.
Spread over the various bond systems, DIAMETAL today offers more than 80 standard bonds, with new ones being added almost daily. This unique choice allows us to offer solutions for virtually any grinding task. And if things get really tight, we even go as far as modifying a standard bond specially for a customer.
Resin bonds - "B"
The usual bonding agents in resin bonds include phenol and imide resins. The short-term thermal load capacity of these bonds is between 250°C and a maximum of 350°C. Resin-bonded grinding tools have an excellent cutting capacity and a cool cut, designed for use in a wide variety of applications both with Diamond and in CBN. Certain bonds can also be used for dry grinding.
Due to economies of scale and the low press temperature, grinding tools with Resin bond are usually the best bargain among the various systems. As a result of their limited mechanical strength, resin-bonded grinding tools tend to reach the end of their stability of shape somewhat quicker than, for instance, metal or metal-vitrified bonds.
But, if the grinding process demands very fine surfaces, resin-bonded grinding tools are perfectly efficient and adequate for the job.
Metal bonds - "M"
The bond agents used in metal bonds include various different bronze alloys. The thermal load capacity of these bonding systems can be as high as 600°C. Due to their superb grit retention power, metal-bonded grinding tools have an excellent stability of shape - a decisive point when grinding profiles, for instance. The ability of leaking off grinding heat much better makes these bond systems the ideal choice for flute grinding (mills, drills, etc.), with enhanced productivity.
Metal-vitrified bonds "MV" (VC for Diamond / V2 for CBN)
As in classic vitrified bonds, the bond agents used in metal-vitrified bonds includes various glass grades. They differ from classic vitrified bonds only in their manufacturing process. Classic vitrified bonds are “pressure-free sintered“, i.e. stoved in the furnace without pressing. Similar to metal bonds, metal-vitrified bonds are pressed under high temperatures. The thermal load capacity of these bond systems is similar to that of metal bonds (approx. 600°C). Typical applications for metal-vitrified bonds are internal grinding, cutting sapphire and oxide ceramic, honing tools and - for CBN - purling and flute grinding.
Vitrified bonds "V"
We are now talking of the classic ceramic or vitrified bond, made with glass and without pressing. The thermal load capacity of this bond system is between 600°C and 700°C. Vitrified bonds have an excellent dressing capacity, allowing these grinding tools to return to their original shape easily once they lose their grinding rim geometry. This also allows for a reproducible dressing process capable of being automated, as a rule on the machine.
Another advantage of vitrified bonds is the controllable porousness of the grinding rim during production, ranging from a closed to a very open rim structure. No other bond system allows a similar range.
High porousness enhances the coolant transport, improves chip removal and reduces the contact surface / the grinding force and therefore the process heat. These benefits are particularly pronounced in material removal grinding operations. The main applications for vitrified bonds are found in steel machining (CNB wheels), particularly in flat, external, internal and tool grinding.
Dressing is an element deserving special attention in vitrified bonds. A few notes on this subject may therefore be of interest:
- use rotating dressing tools whenever possible
- always make small feeds (0.002 to max. 0.01 per overrun)
- never run over the grinding wheel without feed control
- dress with cooling, whenever possible
Depending on machine options, the following dressing tools are commonly used today:
- Diamond dressing (form) roller
- PCD wheels
- vane-type dressers with Diamond cup weehl
- Crushier wheels
- Silicon carbide wheels
- MKD tiles
- multigrit Diamonds
Electroplated bonds - "G"
For these bond systems, please refer to our special catalog Electroplated Precision Grinding Tools in Diamond and CBN.