Metal cutting fluids play an important role in metal cutting and grinding processes. The selection of a suitable metal cutting fluid can reduce the cutting temperature by 60-150 ° C, improve the surface quality by 1 to 2, reduce the cutting resistance by 15% to 30%, and double the service life of the tool and the grinding wheel. The chip and ash can be washed away from the cutting zone, thus improving production efficiency and product quality. Therefore, it is widely used in machining. As global environmental awareness increases and environmental regulations become more stringent, the negative impact of cutting fluids on the environment is becoming more apparent. According to statistics, 20 years ago, the cost of cutting fluid was less than 3% of the cost of the workpiece. At present, in high-productivity production enterprises, the supply, maintenance and recycling costs of cutting fluid account for about 15% of the manufacturing cost of the workpiece. And the tool costs only account for 2% to 5%. About 22% of the total cost associated with cutting fluids is the processing cost of cutting fluid. It is estimated that if 20% of the cutting process uses dry machining, the total manufacturing cost can be reduced by 1.6%. Green manufacturing that is environmentally friendly is considered a modern manufacturing model for sustainable development. Dry cutting without any cutting fluid in the process is a green manufacturing process to control the source of environmental pollution. It can obtain clean, non-polluting chips, eliminating the need for cutting fluid and its processing, etc., which can be further reduced. Cost of production. Therefore, the direction of future machining is to use or use as little cutting fluid as possible. With the development of high temperature tool materials and coating technology, dry machining has become possible in the field of machine building. Under such a historical background, dry cutting technology emerged as the times require, and it has developed rapidly since the mid-1990s. Although its development history is not long, it is a frontier research topic of today's advanced manufacturing technology. 2. Dry cutting technology Dry cutting is a processing method that does not use cutting fluid during processing. Dry cutting is not simply to stop using the cutting fluid, but to ensure high efficiency, high product quality, high tool life and reliability of the cutting process while stopping the use of cutting fluid. This requires the use of dry cutting tools with excellent performance. Machine tools and auxiliary facilities replace the role of cutting fluid in traditional cutting to achieve true dry cutting. First of all, to understand the role of cutting fluid in the traditional cutting process, the general cutting fluid has three main functions: 1 cooling, taking away the heat generated by cutting, reducing tool wear and preventing oxidation of the workpiece surface. 2 Lubrication, reduce friction, reduce cutting force, and ensure smooth cutting. 3 chip removal, quickly take away the chips on the surface of the workpiece and prevent the chips from scratching the surface of the workpiece. From the perspective of environmental protection, the negative effects of cutting fluid are more and more obvious, mainly in the following aspects: 1 The high temperature generated during processing causes the cutting fluid to form a misty volatilization, pollute the environment and threaten the health of the operator. 2 Certain cutting fluids and adhesive tapes The cutting fluids of the cutting fluid must be treated as toxic and hazardous materials, and the processing cost is very high. 3 Leakage and overflow of cutting fluid have a great impact on safe production. 4 cutting fluid additives (such as chlorine, sulfur, etc.) will cause harm to the operator's health and affect the quality of processing. Dry cutting technology puts higher demands on machine tools, tool technology and operators. 3. Advantages of dry cutting technology Dry cutting technology is a green cutting technology developed to adapt to the world's rising environmental requirements and sustainable development strategies. The University of Michigan Technical University (MTU) conducted a large number of investigations and comparative cutting tests, and in-depth analysis of the effects of using cutting fluid on tool life, worker health, cutting force and torque, and processing quality. (1) Tool life It is generally believed that the addition of cutting fluid during cutting can increase the life of the tool. However, from the MTU cutting speed of v=130m/min, the cutting test proved that the cutting of the cutting fluid caused irregularity due to the discontinuity of the filling process and the unevenness of the cooling degree. The alternating cold and heat change easily cause cracks in the cutter head, which in turn causes damage to the cutter and greatly reduces the service life of the cutter. (2) Worker's health The use of cutting fluid will deteriorate the production environment, cause long-term exposure, and can infect skin diseases and bronchitis, posing a threat to workers' health and safety. Therefore, many countries, strict sanitation a predetermined criteria, e.g., by the US Environmental Protection Agency (EPA) regulations, required to allow the content of harmful substances in the air, from the original 5.0mg / m 3 decreased 0.5mg / m 3. And the particles allowed by harmful substances in the air are reduced from the original 10 μm to 2.5 μm. To achieve such a standard, it requires a high-precision cutting fluid filtering device, an air cleaning device, etc., and the cost is considerable. (3) Surface roughness More than 100 cutting tests from the MTU on the drilling process have shown that the dry cutting without the cutting fluid will greatly reduce the surface roughness Ra of the inner hole than the filling of the cutting fluid. Cutting test conditions: The processing materials are Al304 and Al390, and the cutter is made of uncoated carbide drills, and the cutting parameters used in the usual drilling are selected. They also performed comparative cutting tests on the above aluminum alloy for boring. The results show that under the same processing conditions, the surface roughness of the obtained inner hole has little to do with the addition of the cutting fluid. (4) Cutting force and moment They used a surface-coated carbide drill for dry cutting tests. Due to the high hardness, good cutting performance and good lubrication of the coated tool (the same effect as adding the cutting fluid, the friction between the tool and the workpiece is reduced), so that the cutting is performed on the drill bit. The measurement data of force and moment is basically equal to the case of adding cutting fluid. Similarly, a comparative cutting test was performed on the above aluminum alloy for boring. The results show that under the same processing conditions, the amount of cutting force and moment acting on the drill bit, plus or without the cutting fluid, is almost the same. (5) Cutting heat and inner hole size accuracy The MTU is used to measure the cutting temperature of the test piece in the boring test, and the cutting temperature is measured at different axial and radial positions, and the finite element analysis is performed according to the cutting temperature. The results show that without cutting the cutting fluid, the cutting temperature at different positions of the inner hole of the test piece can be increased, which will increase the size of the machined inner hole. Therefore, for the machining of parts with high dimensional accuracy requirements, there is indeed a problem of whether or not to add cutting fluid. From the above aspects, it can be considered that the dry cutting can be completely performed for the non-closed cutting process in which the dimensional accuracy of the part and the surface quality are not high. For non-closed machining with high dimensional accuracy and high surface quality, a series of technical measures are required, such as increasing the spindle speed and reducing the feed rate, which will inevitably increase production costs. However, after calculation and analysis, these costs are exactly equal to the cost of canceling the cutting fluid. In addition to the use of new manufacturing techniques, such as the use of new tool materials, high-speed cutting technology, etc., dry machining technology can be used. Therefore, dry cutting has a good development prospect. Next page Sponge Products,Sponge Block,Foam Brush,Sponge Round Brush PRO-CHARGER CO., LTD. (VICTOR HERO HOLDINGS LTD, TIME VALUE LTD.) , https://www.pro-chargerco.com
1. The origin of the problem