Silicon has a corrosive effect on cemented carbides. Although aluminum alloys with more than 12% Si are generally referred to as high-silicon aluminum alloys, diamond cutting tools are recommended. However, this is not absolute. The increasing silicon content gradually increases the destructive power of cutting tools. Therefore, some manufacturers recommend the use of diamond tools when the silicon content exceeds 8%.
Aluminum alloys with silicon contents between 8% and 12% are a transition zone. Both ordinary carbide and diamond tools can be used. However, the use of hard alloys should use PVD (Physical Plating) method without aluminum. Elemental, thin film thickness tool. Because the PVD method and the small film thickness make it possible to maintain a sharp cutting edge on the cutting tool (otherwise the cutting of the aluminum alloy is not sharp enough to avoid adequate passivation of the cutting edge to avoid abnormal growth of the film at the cutting edge). , and the film material containing aluminum may make the blade film and the workpiece material affinity and damage the combination of film and tool matrix. Because the ultra-hard coatings are mostly aluminum, nitrogen, and titanium compounds, the chipping may be caused by a small amount of peeling of the cemented carbide substrate as the film peels off.