Silicon has a corrosive effect on cemented carbide. Although aluminum alloys exceeding 12% Si are generally referred to as high-silicon aluminum alloys, diamond tools are recommended, but this is not absolute, and the increasing silicon content increases the destructive power of the tools. Therefore, some manufacturers recommend the use of diamond tools when the silicon content exceeds 8%.
Aluminum alloys with a silicon content between 8% and 12% are a transition zone, either ordinary carbide or diamond cutters. However, the use of cemented carbide should use a PVD (physical coating) method, without aluminum, a tool with a small film thickness. Because the PVD method and small film thickness make it possible for the tool to maintain a sharper cutting edge (otherwise, in order to avoid abnormal growth of the film at the cutting edge, it is necessary to passivate the cutting edge sufficiently, the cutting aluminum alloy will not be sharp enough) The aluminum material of the film material may cause the blade film layer to interact with the workpiece material to break the bond between the film layer and the tool substrate. Because the super-hard coating is mostly a compound of aluminum, nitrogen and titanium, it may cause chipping due to a small amount of peeling off of the cemented carbide substrate as the film peels off.
One of the following three types of tools is recommended:
1. Uncoated ultra-fine particle cemented carbide tool
2. Carbide tools with no aluminum plating (PVD) method, such as TiN, TiC, etc.
3. Using diamond cutters
The chip space of the tool should be large. It is generally recommended to use 2 teeth, and the front and rear corners should be large (such as 12°-14°, including the end tooth back angle).
If it is just a general milling surface, it can be used with a 45° lead angle indexable face milling cutter, and a blade specially designed for machining aluminum alloy should be better.
Common aluminum plate thickness: high-grade metal roofing (and curtain wall) system is generally 0.8-1.2mm (compared to the traditional general ≥ 2.5mm).