Struers Discotom-2, Instruction Manual

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Discotom-2
Instruction Manual
12
During the cutting operation the following factors, among others, may
affect the cutting rate of the wheel:

The hardness of the cut-off wheel

The hardness and properties of the specimen

The size of the specimen

The force at which the cut-off wheel is pressed against the
specimen

The quality and condition of the machine (thus, for instance,
worn bearings will cause vibration)
It is very difficult to decide in advance which cut-off wheel to use for a
given specimen. Also, it largely depends on which type of cutting is
desired and on the purpose for which the specimen is being
prepared. For these reasons more than one type of cut-off wheel
should be used. The following properties are determining in the
choice of cut-off wheel:

The ability of the wheel to effect a cutting without deformation of
the specimen surface and without change of the metallographic
structure, e.g. by overheating.

The ability of the wheel for fast cutting.

The ability of the wheel for cutting a wide variety of metals.

The ability of the wheel to resist wear.
These criteria form the basis for Struers program of cut-off wheels. A
general rule applies to the choice of cut-off wheels for specific tasks:

Hard specimens - soft wheels

Soft specimens - hard wheels
Generally, the hardest wheel, producing a flawless cut should be
selected for any given material. At the same time consideration
should be given to the most suitable type of abrasive agent for the
material to be cut.
Diamond cut-off wheels are used for materials too hard for ordinary
cut-off wheels with Al
2
O
3
or SiC grains.
The "Rimlock" type is a metal wheel in which diamond particles are
lodged in small pockets near the periphery. It is a low-cost diamond
wheel, mainly used for mineralogical purposes.
In the "Continuous Rim" type the diamonds are arranged in a soft
metallic or plastic bond forming the periphery of a steel disc. This
type of wheel provides cutting of very high quality and is used for
silicon, germanium, mineralogical and geological materials, etc.
Please refer to the Selection Guide in the
Struers Cut-off Wheels
brochure .
Choice of Cut-off Wheel