The cutting fluid is selected correctly, and the precision and tool life are "doubled"
January 30, 2023
In order to adapt to different processing requirements, there are many kinds of cutting fluids, which can be divided into water-based cutting fluids and oil-based cutting fluids according to chemical composition and state.
Generally, the cutting fluid diluted with water is called water-based cutting fluid, and the cutting fluid used without water dilution is called oil-based cutting fluid. Water based cutting fluid Anti rust emulsion Compared with oil-based cutting fluid, emulsion has the advantage of good cooling effect. Generally, the water solution diluted at 5%~10% has low cost and is safe to use. The biggest disadvantage of emulsion is its poor stability, easy to be eroded by bacteria and mold, and short service life Anti rust lubricant and emulsion It has good lubricity, but the disadvantage is that these animal and vegetable fats or long-chain unsaturated fatty acids are easy to be decomposed by microorganisms and molds, and the service life is very short. Extreme pressure emulsion It has strong extreme pressure sliding property, and can be used for heavy cutting such as tapping, broaching, and tape cutting, as well as processing difficult to cut materials such as stainless steel and heat-resistant alloy steel. Oil based cutting fluid Grease anti oil (or oily additive)+mineral oil Grease oil proof has strong adsorption performance on metal surface and good lubrication performance. Its disadvantage is that it is easy to be oxidized and deteriorated, and it forms a mucous membrane on the surface of the machine tool that is difficult to clean (i.e. "yellow gun"). It is generally used for precision cutting such as fine turning soft rod, gear hobbing and gear making. Active extreme pressure cutting oil It has good anti sintering performance and extremely long lubrication, can improve the service life of the tool under high temperature and high bed conditions, and has strong control ability to the tool chip buildup. It is mainly used for cutting materials easy to gnaw and difficult to machine materials. Non active extreme pressure cutting oil Good extreme pressure lubricity, non corrosive to nonferrous metals. It is easy to use and widely used in various cutting processes. Composite cutting oil The use of oil-based additives, such as high-grade fatty acids and fatty oils, can produce physical and chemical adsorption on the metal surface, forming a molecular film adsorption layer, which can reduce the friction resistance during cutting, maintain good lubrication in a wide temperature range, and is suitable for multi station cutting and cutting of various materials. Select cutting fluid according to the tool Knowing the types and characteristics of cutting fluid, how can we match it with our daily tools? High speed steel cutter This material is a high-grade alloy steel based on chromium, nickel, tungsten, molybdenum and vanadium (some also contain aluminum). Their heat resistance is obviously higher than that of tool steel, and the maximum allowable temperature can reach 600 ℃. It has high toughness and is suitable for workpieces with complex geometry and continuous cutting, and high-speed steel has good machinability and is easily accepted in price. High speed steel cutter
Due to poor red hardness of high-speed steel tools Cutting fluid is required 1. Oil based cutting fluid or emulsion is recommended for low and medium speed cutting. 2. In high speed cutting, due to the large amount of heat, it is appropriate to use water-based cutting fluid. 3. During finishing, extreme pressure emulsion or extreme pressure cutting oil is used to reduce friction, improve surface quality and accuracy, and extend tool life. If oil-based cutting fluid is used, more oil mist will be generated, which is easy to cause workpiece burns, reduce processing quality and increase tool wear. In addition, extreme pressure aqueous solution or extreme pressure emulsion is recommended for rough machining. Carbide cutter Cemented carbide is composed of tungsten carbide (WC), titanium carbide (TiC), tantalum carbide (TaC) and 5%~10% cobalt. Its hardness is much higher than that of high-speed steel. The maximum allowable working temperature can reach 1000 ℃. It has excellent wear resistance. When processing steel materials, it can reduce the adhesion between chips. Solid carbide tool
Hard alloy tool has good red hardness When processing general materials
Generally, dry cutting is adopted without cutting fluid 1. In dry cutting, the temperature rise of the workpiece is relatively high, which makes the workpiece prone to thermal deformation and affects the machining accuracy of the workpiece. Therefore, when selecting cutting fluid, the sensitivity of cemented carbide to sudden heat should be considered, and the tool should be heated evenly as far as possible, otherwise it will lead to edge collapse. 2. For high-speed cutting, large flow cutting fluid should be used to spray the cutting area, so as to avoid uneven heating of the tool and blade collapse, and also reduce the soot pollution caused by evaporation due to excessive temperature. Ceramic cutter This material is made of aluminum oxide, metal and carbide sintered at high temperature. Its high-temperature wear resistance is better than that of cemented carbide, so it is generally dry cutting. Ceramic cutter
Considering uniform cooling and avoiding excessive temperature, water-based cutting fluid is also often used, but it is better to pour continuously and fully without interruption. Diamond cutter Diamond tools have very high hardness and are generally used for dry cutting. In order to avoid high temperature, like ceramic materials, water-based cutting fluid is used in many cases. Diamond cutter
The reasonable selection of cutting fluid according to different tool materials can not only improve the surface quality and machining accuracy of the workpiece, but also reduce the thermal deformation of the workpiece and the wear of the tool, improve the durability of the tool and reduce the production cost. It is not easy to find a cutting fluid that fits the tool exactly.
