At present, most of the metal cutting processing is carried out in the wet method mainly using cutting fluid, because the cutting fluid has the functions of cooling, lubrication, cleaning and chip removal, which plays an important role in prolonging the service life of the tool and ensuring the processing quality. , but in recent years, as people pay more and more attention to environmental protection, a series of negative effects brought by cutting fluid have also attracted much attention. In order to protect the environment and reduce processing costs, dry cutting is a method of consciously not using cutting fluid and performing cutting operations without cutting fluid. However, dry cutting is not simply to stop the use of cutting fluid, but to ensure high efficiency, high product quality, high tool durability and reliability of the cutting process while stopping the use of cutting fluid, which requires excellent performance. Dry cutting tools, machine tools and auxiliary facilities replace the role of cutting fluid in traditional cutting to realize dry cutting in the true sense.
Dry Cutting Features 1. There will be no safety accidents and quality accidents related to cutting fluid. 2. The chips are clean and pollution-free, easy to recycle and handle, and will not cause environmental pollution. 3. The separation device for cutting fluid and chips and the corresponding electrical equipment are omitted. The machine tool has a compact structure and reduces the floor space. 4. The cutting fluid transmission, recovery, filtration and other devices and corresponding costs are omitted, the production system is simplified, and the production cost is reduced.
Tool material selection 1. Ultrafine carbide material. Superfine cemented carbide can improve the toughness of ordinary cemented carbide, has good wear resistance and high temperature resistance, and is suitable for dry machining of milling and drilling. 2. Ceramic materials. It has good red hardness, but poor thermal toughness, so it is suitable for dry turning, not dry milling. 3.CBN material. High hardness, good thermal conductivity, good high temperature chemical stability, can be replaced by turning grinding. 4. PCD material. With very high hardness and good thermal conductivity, it is more suitable for dry machining of copper, aluminum and aluminum alloy workpieces.
Dry Cutting The key to the role of dry cutting in machining is to find an alternative to cooling and lubrication. There are two successful dry cutting methods: high-speed dry cutting and low-temperature cold air cutting. High-speed dry cutting The processing method is to use a high cutting speed for cutting without the action of cooling and lubricating agents. Dry cutting must select appropriate cutting conditions. First, use a high cutting speed to minimize the contact time between the tool and the workpiece, and then use compressed air or other similar methods to remove chips to control the temperature of the work area. Since it eliminates the oil chip separation process, no cooling oil tank and oil chip separation device and corresponding electrical equipment, the machine tool is compact. And this method greatly improves the processing environment; the processing cost is also greatly reduced. In order to further prolong the life of the tool and improve the quality of the workpiece, 10-1000ml of lubricating oil per hour can be used for micro-lubrication during the dry cutting process. The chips produced by this method can be considered as dry chips, and the precision, surface quality and internal stress of the workpiece are not negatively affected by trace amounts of lubricating oil.
Low temperature cold air cutting The cutting method is a processing method in which cooling and lubricating agent cooling are replaced with cold air at -10 to -100°C and a very small amount of vegetable oil. The study found that in the process of metal cutting, if only a very small amount of vegetable oil with good lubricating effect and not oxidized is provided to the processing point, the processing point will lose lubricity due to high temperature. If cold air (-10～-100℃) is supplied to the processing point, the high temperature of the processing point can be prevented, and the above situation can be avoided. The cutting performance is greatly improved during cold air cutting. The test shows that the performance of cold air cutting and grinding is more than 2 times higher than that of oil cutting and grinding.
