CoroMill 790 dedicated for aluminium.
The machinability of aluminium differs primarily depending on the Si-content. Hypo-euthectic is the most common type, with a Si-content below 13%.
The ISO N material group includes not only aluminium, but also magnesium, copper and zinc based alloys.
Aluminium with Si-content below 13%
Material Classification: N1.1-3
- The dominant wear criteria are built-up edge/smearing on the edges, leading to burr formation and surface finish problems.
- In cast aluminium sand inclusion can sometimes be a problem.
- Good chip formation and evacuation are crucial for avoiding scratch marks on the component surface.
Suitable cutter concepts
Cutters developed primarily for milling of aluminium are:
- CoroMill Century
- CoroMill 790
- CoroMill Plura R216.32, R216.33 and R216.42
Most other CoroMill cutters can be used in aluminium simply by choosing a dedicated insert geometry and grade.
Choose positive insert geometries with sharp edges
- Use uncoated carbide grades (H13A, H10) when Si-content is below approx. 8%
- When the Si-content is above approx. 8%, PCD-inserts (CD10) normally provide better machining cost efficiencies.
CoroMill Century for face milling of aluminium.
PCD-tipped insert, CoroMill Century
- Unlike most other milling applications, cutting fluid should always be used in aluminium to avoid smearing on the insert edges and to improve surface finish.
- A higher cutting speed generally improves the performance and does not negatively effect tool life.
- A hex value of 0.10-0.20 mm is recommended. Values that are too low can lead to burr formation.
Warning: Make sure that the maximum rpm for the cutter is not exceeded
- Due to the high table feeds, a machine with ”look-ahead” function should be used to avoid dimensional errors.
- Tool life is always limited by the burr formation or surface finish on the component. Wear on the insert is difficult to use as a tool life criteria.