How to choose the cutting fluid for aluminum alloy processing

Compared with most steel and cast iron materials in terms of physical properties, aluminum alloy has higher strength and hardness than pure aluminum.

Jiahangaero said that because the aluminum alloy is soft and has great plasticity, it is easier to stick to the tool during cutting, forming built-up edge on the tool, and welding may occur on the edge of the tool during high-speed cutting, which will cause the tool to lose its cutting ability and affect the machining accuracy and surface roughness. In addition, the thermal expansion coefficient of aluminum alloy is large, and cutting can easily cause thermal deformation of the workpiece and reduce machining accuracy.

Selection of Cutting Fluid for Aluminum Alloy Machining

The choice of cutting fluid for aluminum alloy processing is very important, and must ensure good lubricity, cooling, filterability and rust resistance. Therefore, the cutting fluid used for aluminum alloy processing is different from ordinary cutting fluid, and it is very necessary to choose a suitable cutting fluid.

According to the different requirements of processing conditions and processing accuracy, different cutting fluids should be selected.

Because high-speed machining will generate a lot of heat, such as high-speed cutting, drilling, etc., if the heat generated cannot be taken away by the cutting fluid in time, the phenomenon of sticking to the knife will occur, and even built-up edge will appear, which will seriously affect the quality of the workpiece. Machining roughness and the service life of the tool, at the same time, the heat will also deform the workpiece, which seriously affects the accuracy of the workpiece. Therefore, the choice of cutting fluid should consider not only its own lubricity, but also its cooling performance.

In terms of cutting fluid selection, in addition to the lubricity and cooling properties of the cutting fluid, Jiahangaero said that the rust resistance, cost and easy maintenance of the cutting fluid should also be considered. The cutting oil is selected from base oil with relatively low viscosity and added anti-friction additives, which can not only achieve lubrication and anti-friction, but also have good cooling and easy filterability. However, the problem of cutting oil is low flash point, heavy smoke during high-speed cutting, high risk factor, and fast volatilization, which increases the user cost accordingly. Therefore, if conditions permit, try to use water-soluble cutting fluid.

For water-based cutting fluid, Jiahangaero said that it is more important to consider its rust resistance. The commonly used water-based aluminum rust inhibitors include silicates and phosphate esters. For workpieces that have been stored for a long time between processes, it is easy to use cutting fluids with phosphate ester-type rust inhibitors during processing, because silicon and aluminum are long-lasting. Corrosion occurs with time exposure to produce black "silicon spots". The pH value of the cutting fluid is usually kept at 8-10. If the rust resistance is not good, aluminum is easily corroded under such alkaline conditions. Therefore, the water-soluble cutting fluid must have good aluminum rust resistance.