Aluminum is a great material for precision CNC machining, but you may run into problems if you are machining parts to be very thin. Because it radiates heat very well, and it is not too hard, it sometimes causes deformation in the part you are trying to machine. Luckily, a lot of this can be prevented if you take some of the following precautions when CNC machining aluminum.
The most important part is using the cutting tools correctly. If the cutting tools get worn, the project’s cutting surface gets rougher and the cutting temperature rises. When the cutting temperature rises the chance of part deformation increases. When you begin using a new cutter, it is always a good idea to use a fine oil stone to carefully file the front and rear edges to eliminate any burrs. This minimizes heat buildup and cutting deformation. Keeping your cutting tools sharp at all times makes this process efficient and produces high-quality results.
Know the proper angles to approach a project with and how to get the best effect from them. The most important angle is your main deflection angle. Because of the properties of aluminum, you need to have a large capacity for chip space as the milling cutters work. If you have a lower number of cutting teeth on the milling tool, this increases the capacity of this space and helps avoid the deformation of thin-walled parts caused by chips clogging the workspace.
When using a CNC machine to cut aluminum parts it is best to complete a rough cut of the project by cutting away the excess aluminum on the block at the fastest possible cutting speed. When that has been completed, you need to set up the CNC for a finishing pass in order to focus on precision and producing a well-cut surface. As the depth of the cuts get shallower, the pressure that causes deformation of the part is also reduced.
Holes and deeper cavities are a challenge for precision CNC machining because if the cutter works on them from the top and drills down, there is not enough space for the debris to go, so it accumulates in the cutting area. This creates a lot of heat which can easily cause deformation of the part as well as possibly breaking it (or the cutting tool itself).
The best way to address this is to drill a hole in the area where there needs to be a cavity that is slightly larger than the milling cutting tool. Since the cutter has a clear area to move within the cavity, there is more space for debris, less heat buildup, and less stress on the part and the cutting instrument.
At Getec Industrial, we specialize in providing the best CNC machining for aluminum services. We have over 85 milling machines at 12 CNC turning centers in order to provide high-quality aluminum products quickly. Give us a call at 888-999-8499, contact us online, or send us an email at sales@getecna.com to speak to one of our precision CNC machine experts today.
