[ALUMINIUM NETWORK] Aluminum alloys have many obvious characteristics in terms of physical properties compared with most steel and cast iron materials: strength, hardness, and purity are much higher than those of pure aluminum, but they have lower strength and hardness than steel, cutting Small force, good thermal conductivity. Because the aluminum alloy is soft and plastic, it is easy to stick to the knife during cutting, and the built-up edge is formed on the cutting tool. During high-speed cutting, welding may occur on the cutting edge, which causes the cutting tool to lose its cutting ability and affect the machining accuracy and surface roughness. In addition, the coefficient of thermal expansion of the aluminum alloy is large, and the heat of cutting easily causes the thermal deformation of the workpiece and reduces the processing accuracy. First, the choice of aluminum alloy cutting fluid In summary, the selection of aluminum alloy machining cutting fluid is very important, must ensure good lubricity, cooling, filtration and rust resistance, therefore, for aluminum alloy machining cutting fluid and general cutting fluid is different, choose A suitable cutting fluid is very necessary. According to the different requirements of processing conditions and machining accuracy, different cutting fluids should be selected. Due to high-speed machining, a large amount of heat can be generated, such as high-speed cutting, drilling, etc. If the generated heat cannot be taken away by the cutting fluid in time, the sticking knife phenomenon will occur, and the built-up edge will appear, which will seriously affect the workpiece. Processing roughness and tool life, while the heat will also cause the workpiece to deform, seriously affecting the accuracy of the workpiece. Therefore, the choice of cutting fluid must consider its own lubrication, but also consider its cooling performance. For grinding, grinding debris is very fine, and a lot of heat is generated during the grinding process. Therefore, when selecting the cutting fluid, it is necessary to consider both lubrication and cooling performance, and also to consider the filterability of the cutting fluid. If the viscosity of the selected cutting fluid is too large and the chips cannot be deposited or filtered out in time, the cutting surface will be scratched as the cutting fluid is circulated to the processing area, thereby affecting the finish of the machining surface. Therefore, for low-viscosity or ultra-fine grinding, choose low-viscosity anti-friction grinding oil or semi-synthetic antifriction cutting fluid. In terms of the choice of cutting fluid, in addition to considering the properties of the cutting fluid such as lubricity and cooling properties, it is also necessary to consider the properties of the cutting fluid such as rust resistance, cost, and ease of maintenance. Cutting oil is easy to use the base oil with relatively low viscosity to add anti-friction additives, which can not only achieve lubrication and friction reduction, but also have good cooling and easy filtration. However, the cutting oil has the problems of low flash point, heavy smoke during high-speed cutting, high risk factor, quick volatility, and high user cost. Therefore, as far as conditions permit, water-soluble cutting fluid is used as much as possible. For aqueous cutting fluids, it is more important to consider its rust resistance. The commonly used waterborne aluminum rust inhibitors are silicates and phosphate esters. For workpieces with long storage time between processes, it is easy to use cutting fluids with phosphate type rust inhibitors during processing because silicon and aluminum are long. Corrosion in time can cause black silicon spots. The pH of the cutting fluid is maintained at 8 to 10, and if the rust resistance is not good, aluminum can be easily corroded under this alkaline condition. Therefore, the water-soluble cutting fluid must have good aluminum anti-rust properties. Second, the use and maintenance of aluminum alloy machining cutting fluid The preparation and use of aluminum alloy machining cutting fluid is basically the same as that of ordinary cutting fluid, but it is more stringent in the choice of dilution water. Because many ions in the water will have a corrosive effect on aluminum, if the content of these ions is too much, it will reduce the anti-rust performance of the cutting fluid, especially in the anti-rust between processes, such as chloride ions, sulfate ions and heavy metal ions. In addition, some of the ions will react with the aluminum rust inhibitor in the cutting fluid to reduce the rust resistance and stability of the cutting fluid, such as calcium and magnesium ions. Therefore, try to select the dilution water with less hardness, or the diluted water after ion exchange softening to ensure the use effect and service life of the cutting fluid. In addition to the daily maintenance of ordinary cutting fluids, the maintenance of aluminum alloy machining cutting fluids needs to pay attention to the following points: 1, filter Because the aluminum alloy reacts easily under alkaline conditions to produce aluminum soap and damages the stability of the cutting fluid, the cut aluminum chips should be filtered out immediately to prevent the aluminum chips from reacting with the cutting fluid and affecting the use of the cutting fluid. Effects and service life. In the grinding process, the scraped aluminum scraps are small and light, and it is difficult to settle. If not filtered or filtered, the aluminum scraps will be brought to the processing area along with the cutting fluid circulating system to scratch the workpiece surface. , affect the gloss of the machined surface. 2, pH value Because the aluminum material is very sensitive to the pH of the cutting fluid, it is necessary to regularly test the pH value of the aluminum alloy cutting fluid. If an abnormality is found, it should be adjusted in time. The use of pH control in the 8 to 9, in order to avoid excessive high pH value of the corrosion of the workpiece or the pH value is too low to make bacteria multiply and affect the stability and performance of the cutting fluid. 3, regularly add new liquid It not only guarantees the good lubrication of the cutting fluid, but also guarantees the good anti-rust performance and bactericidal anti-corrosion performance of the cutting fluid so as to prolong the service life of the cutting fluid. Third, the conclusion The selection of cutting fluid for aluminum alloy machining is very important. It is necessary to ensure the good lubricity and rust resistance of the cutting fluid, as well as good stability, filterability and easy maintenance. Only in this way can the products meet the requirements. To reduce the use of cutting fluids to a great extent.