What are the characteristics of aluminum knife coating?
1. Hardness
The high surface hardness brought about by the coating of aluminum knives is one of the ways to increase the life of the knives. In general, the harder the material or surface, the longer the tool life. The titanium nitride aluminum carbide coating has higher hardness than the titanium nitride coating.
2. Wear resistance
Abrasion resistance refers to the ability of a coating to resist abrasion. While some workpiece materials may not be too hard on their own, the elements added during production and the processes used can cause tool cutting edges to chip or become dull.
3. Surface lubricity
A high coefficient of friction increases cutting heat, which can lead to reduced coating life or even failure. And reducing the coefficient of friction can greatly extend tool life. A finely smooth or regular-textured aluminum knife coating surface helps reduce the heat of cutting, as the smooth surface allows the chips to slide quickly off the rake face to reduce heat generation. Coated tools with better surface lubricity can also be machined at higher cutting speeds than uncoated tools, further avoiding high temperature fusion welding with the workpiece material.
4. Oxidation temperature
Oxidation temperature refers to the temperature at which the coating begins to decompose. The higher the oxidation temperature value, the more favorable it is for machining under high temperature conditions. Although the room temperature hardness of the coating may be lower than that of the coating, it has proven to be much more effective in high temperature processing. The reason the coating retains its hardness at high temperatures is that a layer of alumina forms between the tool and the chip, which transfers heat from the tool to the workpiece or chip.
5. Anti-sticking
The anti-adhesion properties of the aluminum knife coating prevent or mitigate chemical reactions between the tool and the material being machined, preventing workpiece material from depositing on the tool. When machining non-ferrous metals (such as aluminum, brass, etc.), built-up edge (BUE) is often generated on the tool, resulting in tool chipping or workpiece size out of tolerance. Once the material being machined begins to adhere to the tool, the adhesion will continue to expand.
