Machine Tool
Into the machining field a
cutting tool is a tool that remove material from the work piece by a shear
deformation. One of the most important qualities that a cutting tool must
possess is that it retains its hardness at the high temperatures generated
during the cutting process. The most common cutting tool materials used in CNC
applications are:
- HSS
- Cemented carbides
- Ceramics
- Diamond
HSS is alloy of steel containing
between 5% and 20% tungsten. It is known by its ability to maintain a cutting
edge at the elevated temperatures encountered during machining. Others
high-carbon steels can have the same hardness as HSS, but they lose their
hardness at the elevated temperatures found at the cutting edges.
Cemented Carbide is another
common cutting tool material. Carbides are extremely hard materials and are
able to handle a great amount of heat during long periods. Due its hardness
carbides must be machined by either grinding or electrical discharge machining.
They cost considerably more than their HSS counterparts, but when the
productivity gains are measured against cost, carbides are the best choice.
Ceramic cutting tool materials
are formed from sintered aluminum oxides. This material present great
performance at higher cutting speeds than cemented carbides and exhibit better
wear resistance. This is primarily due to the lower temperatures generated at
the tool tip. Its popularity is probably reduce due its deficient capacity for
work with intermittent cutting.
Diamond is natural material with
extremely good wear-resistance properties. It resists compression forces twice
as well as tungsten carbide and expand very little with heat. For these reasons
it can hold very close tolerances during machining and produces an extremely
high-quality surface finish.
When machining ferrous components, chemical
reaction at high cutting temperatures can cause diamond to revert to its
original graphite form. For this reason the cutting tool material is limited to
the machining of non-ferrous and non-metallic materials. Polycrystalline
diamond is a synthetic diamond mostly used in CNC application due to its
super-hard constituents.
Contact ALNO
