Page 53 - Iscars_World_Brochure_2018

Most cemented carbides used for producing cutting
tools integrate wear-resistant coating and are known
as “coated cemented carbides”. Applying a thin-
layer coating to a cemented carbide considerably
improves the carbide’s working characteristics and
the coating may be one- or multi-layer, depending
on the number of coating materials. These include
3
TiC, alumina (Al 2 O ), titanium carbo-nitride (TiCN),
and titanium aluminum nitride (TiAlN). Post-coating
treatment processes are applied to already coated
cemented carbide, for example, to the rake surface
of an indexable insert.

Coating Processes
Two methods may be utilized for coating: Chemical
Vapor Deposition (CVD) and Physical Vapor
Deposition (PVD). CVD coating is based on chemical
reactions in a vaporized medium and PVD uses
material sputtering. Technology development
allows both methods to be combined for coating
cemented carbides, as a means of controlling
coating properties. For example, ISCAR’s carbide
grade DT7150 features a tough substrate and a
dual MT CVD (Medium Temperature CVD) and TiAlN
PVD coating. The grade was originally developed to
improve machining special-purpose hard cast iron.

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