Dry cutting technology (2)

4. Status of dry cutting technology

The scientific definition of dry cutting was officially established in 1995. At the 1997 International Conference on Production Engineering (CI RP), Professor F. Klocke of the Aachen University of Technology in Germany gave a keynote report on “dry cutting”; January 1999 At the National Science Foundation “Design and Manufacturing Discipline” grantee conference, Dr. BPErdel, President of the internationally renowned tool manufacturer MAPAL, also gave a keynote report on the development of dry cutting in the US. Dry cutting technology has been used in various industries and The academic community has drawn wide attention. At present, industrial developed countries including Europe, the United States and Japan attach great importance to the research of dry cutting. Dry cutting technology has been successfully applied to the production field, which has a certain relationship with the strong industrial base and strict environmental regulations of these countries. Among them, German companies are particularly common. In mass production, 15% of the processing uses dry cutting technology, and has achieved good economic and environmental benefits. Japan has also conducted extensive research on dry cutting, and they have developed several dry machining centers that do not use cutting fluids. On one of the machines, a dry cutting system with liquid nitrogen cooling is used to extract high purity nitrogen from the air. The liquid nitrogen is sent to the cutting zone at a normal temperature of 5 to 6 atmospheres, and dry cutting can be smoothly performed. Research on dry cutting technology in China has also started. Chengdu Tool Research Institute, Tsinghua University and Zhuzhou Diamond Tool Co., Ltd. have systematically studied superhard tool materials (such as ceramics, cubic boron nitride, diamond, etc.) and tool coating technology, and have made a lot of research. Results. China's ceramic tools have formed a certain production capacity, which has laid a solid foundation for the research and application of dry cutting technology. The KT series machining center developed by Beijing Machine Tool Research Institute can realize high-speed dry cutting. Chongqing Machine Tool Plant YKS3112 six-axis CNC automatic dry-cut hobbing machine, large workpiece diameter × 昀 large modulus is 125mm × 3mm, spindle 昀 high speed 1500r / min. However, in general, China still has a large gap in the research of dry cutting theory and abroad. The scale of application in industry is smaller, and we need to accelerate research and popularization and application in the future.

5. Dry cutting tool technology

Dry cutting technology is a huge system engineering that requires a series of measures from the aspects of tool technology, machine structure and process. The relevant tool technologies are:

(1) Using new tool materials

In the past decade or so, the emergence of high hardness materials has made it possible for dry cutting. Dry cutting requires not only high hardness and thermal toughness of the tool material, but also good wear resistance, thermal shock resistance and adhesion resistance.

(2) Coating technology

Coating the tool is an important way to improve tool performance. In the past decade, tool coating technology has developed very rapidly, with up to 15 coating materials, and some tools have 13 layers on the body. The coating process is also becoming more and more mature. With the development of technology, the technical problem of low bonding strength between the coating and the base material has been solved. There are two main types of coated tools: one is a "hard" coated tool, such as Ti N, Ti C and Al 2 O 3 coated tools. These tools have high surface hardness and good wear resistance. Among them, TiC coated tools have a particularly strong resistance to flank wear, while Ti N coated tools have a higher resistance to "crater" wear. The other type is "soft" coated tools such as Mo2S2, WS and other coated tools. This type of coated tool is also called "self-lubricating tool. Its friction coefficient with the workpiece material is very low, only about 0.01, which can effectively reduce the cutting force and reduce the cutting temperature.

(3) Tool geometry design

Dry cutting tools usually have crater wear as the main cause of failure because there is no cutting fluid in the machining, and the temperature of the tool and chip contact area increases. Therefore, it is usually necessary to have a large rake angle and a blade inclination angle, but the blade edge strength is affected after the rake angle is increased. In this case, a suitable negative chamfer or rake face reinforcement unit should be provided, so that the tool tip and The cutting edge will have sufficient volume of material and a reasonable way to withstand cutting heat and cutting forces, while reducing the adverse effects of impact and crater expansion on the tool, allowing the tool tip and cutting edge to remain adequate for longer cutting times. Structural strength. The heat pipe tool is a self-cooling tool, so there is no need to cast the cutting fluid from the outside, especially for CNC machine tools, machining centers and automatic production lines.

6. Summary and outlook

The pursuit of ecological and economic benefits is the main driving force for the development of dry cutting technology. In recent years, with the development of super-hard tool materials, especially tool coating materials, the improvement of tool geometry and the application of micro-lubricating materials, as well as the development of corresponding equipment suitable for dry-cutting machine tools, the dry cutting technology has been strongly promoted. Rapid development. After years of development and experimentation, dry cutting technology has entered the practical stage. Today, quite a few cutting processes can be completely solved by dry or by micro-lubrication. With the continuous improvement of the reliability of the dry cutting process, dry cutting is gradually entering the mechanical processing industry, especially in the mass production fields such as the automobile industry.

For more articles, please refer to "Metal Processing" Cold Processing 2008 No. 1

Previous page

Adjustable Wrench

High carbon steel forged, fully heating treatment, full body polish, White Nickle surface, new PVC plastic handle.

Adjustable Wrench,Adjustable Torque Wrench,Professional Adjustable Wrench,Multi Purpose Adjustable Wrench

Henan Yuanli Tools Co.,Ltd , https://www.hnyuanlitools.com