Page 14 - Iscar Article 2_2017

Milling aluminum appears to be a
remarkably easy process. Often, people not
directly involved in machining aluminum
believe that it’s enough to take a balanced,
sharp, polished tool rotate it at a maximal
speed and set at medium feed - and the
material will cut like butter.
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In comparison with machining steel, aluminum
and its alloys require much less cutting force,
and therefore the cutting edge of a milling tool
experiences relatively low mechanical loading.
Aluminum exhibits high thermal conductivity and
the chips produced when machining aluminum
transfer high levels of generated heat, resulting
in significantly reduced thermal loading of the
cutting edge. Due to these properties, milling
aluminum is characterized by extremely high
cutting speeds and feeds. However, this
does not guarantee that milling aluminum is
quite so simple.
The material characteristics of aluminum result
in the formation of built-up edge (BUE) when
machined. This unwelcome phenomenon
increases the mechanical load on the cutting
edge, making efficient chip flow more difficult to
achieve, affecting the balance of rotating tools
and causing the entire machining process to
be less efficient.
The evacuation of aluminum chips may also be
affected by using the wrong kind of cutting tool.
If the volume of a tool’s chip gullet (flute) is not
sufficient, the long chips during aluminum milling
will clog the tool. Overcoming this obstacle
demands the use of a tool with less teeth or