Aluminum processing-intelligent milling aluminum

Aluminum is a common machining material because of its excellent processability and is therefore the material of choice in most manufacturing industries.

Aluminum as a material offers some interesting thermal and mechanical properties. In addition, aluminum metal is relatively easy to form, especially during drilling, such as in CNC aluminum machining. In fact, we value aluminum alloys more than other light metals such as magnesium and titanium alloys.

Compared with other materials, the processing of aluminum is very simple, at least it looks much easier than steel. Nonetheless, there are still some mistakes that can be made when processing this material, including choosing the wrong tool can affect productivity.

Grinding aluminum seems to be a very easy process. Often misunderstandings arise from people who are not directly involved in aluminum processing. They believe that as long as a balanced, sharp, polished tool is used and rotated at maximum speed, and set at a medium feed speed, the material will cut like butter.

Compared to machining steel, the cutting forces required for aluminum and its alloys are much smaller, so the mechanical load on the cutting edge of the milling cutter is relatively low.

Why is aluminum challenging?

Although the processing of aluminum is simple, it also has certain challenges. The main challenge in efficiently processing aluminum is how to achieve maximum material removal without explosion.

If there is too much heat, the aluminum will melt and melt onto the tool. So even if it cuts like butter, it won't last long if the aluminum sticks to the tool, and you end up with friction stir welding instead of machining.

The main tools considered when machining aluminum are: minimizing the tendency of aluminum to adhere to the cutting edge of the tool; ensuring good chip evacuation from the cutting edge; and ensuring that the core strength of the tool is sufficient to withstand cutting forces without breaking.

Using the wrong cutting tool may also affect the evacuation of aluminum shavings. If the chip flute (groove) of the tool is insufficient, long chips during aluminum milling can clog the tool.

From the viewpoint of workability, aluminum is not a uniform material. Alloying elements (especially silicon), material type (forging, casting) and processing methods all affect cutting performance. Various other factors, such as the shape of the machine parts, working conditions and operating requirements (precision, roughness, etc.) also increase their own limitations, which must be considered when selecting processing strategies and selecting tools. Therefore, in many cases, it is often not easy to process aluminum, especially milled aluminum.

Materials, coatings, and geometries are three elements that are interrelated in tool design to minimize these issues. If these three elements cannot be used simultaneously, high-speed milling cannot be performed successfully. In order to succeed in high-speed machining of aluminum, all three elements must be understood.

The right combination of geometry, materials and processing

Tool manufacturers consider the special features of milling aluminum when developing tools. The keys to success are the right combination of cutting geometry, tool material and tool handling, and options to provide the best coolant supply.

When considering the application of milling aluminum, think of large aircraft components such as wings, doors or window frames. Usually, these parts are produced from a single block, usually weighing several tons, and it is usually necessary to remove 80-85% of the weight of the entire block to produce the final required part shape. In contrast, the global automotive industry is also a large consumer of aluminum, and its components have introduced various hard cast aluminum grades. The increased abrasiveness of these parts can negatively affect tool wear.

The metalworking industry produces large and small aluminum parts, and in many cases requires more sized milling cutters. The size of these tools is not suitable for indexable inserts, and solid carbide tools have obvious advantages. In addition, the high precision of the solid carbide end mill makes it incomparable when used for the finishing of large parts.