High-speed cutting technology is a new type of manufacturing technology that reduces the machining time of tools or parts through a rapid machining process, thereby reducing manufacturing costs.
High-speed cutting technology is also characterized by high precision, making it suitable for machining parts that require high precision. By introducing high-speed cutting technology, companies have greatly improved their production efficiency and market competitiveness.
For high-speed cutting technology, the cutting tool is its main component and is in direct contact with the machined material during the high-speed cutting process. Therefore, the performance of the cutting tool directly affects the cutting effect.
There are many cutting tool materials suitable for high-speed cutting, such as diamond, boron nitride, hard alloy and ceramic materials. However, each material has its own suitable field of application, and with the continuous emergence of new materials, there are more and more materials that can be used in high-speed cutting tools, providing a material basis for improving the speed and cutting precision.
Hard League
Hard alloy is an alloy material made by the powder metallurgy process of hardening refractory metal compounds and metal bonding. It has high hardness, heat resistance and other characteristics, and can be practically used to cut materials such as cast iron, glass, common stone, stainless steel and non-ferrous metals.
However, this material is no longer suitable as an independent cutting tool material as the requirements for cutting processes continue to increase.
Modified hard alloy materials
2.1 Hard alloy doping materials
With the development of cutting technology, single hard alloy cutting tools are unsuitable in terms of hardness, wear resistance and thermal hardness.
Therefore, people have modified hard alloys by adding materials such as nickel, cobalt, and tungsten carbide to improve their properties. The research found that the performance of modified hard alloys in terms of hardness, oxidation resistance, wear resistance and thermal hardness was improved to varying degrees.
For commonly used titanium carbide-based hard alloys, adding nitrides can greatly improve their performance. However, this material is not suitable for processing ultra-high temperature metals, high temperature alloys and non-ferrous metals.
2.2 Coated hard alloy materials
Due to the insufficient performance of common hard alloys to meet the requirements of modern high-speed cutting, coating one or more layers of other materials with high hardness, wear resistance, good lubricity and high melting point on the surface of alloy cutting tools hard can greatly improve your performance.
Currently, materials such as titanium carbide, alumina, diamond and nanomaterials can be used to coat hard alloy cutting tools.
Among them, a single layer of titanium carbide coating can increase the hardness of the tool to a certain extent and increase the cutting speed. It also has high thermal conductivity. Alumina coating has greater resistance to oxidation and wear, but lower thermal conductivity.
Therefore, in practical applications, these two materials are often combined with a third material to form a multilayer coating, taking advantage of each material to significantly improve the cutting performance of the tool.
Diamond coating uses chemical vapor deposition to form a thin layer of diamond film on the surface of hard alloy cutting tools, giving them the properties of diamond materials. Both the hardness and stability of common hard alloy cutting tools are significantly improved.
Furthermore, the cost is much lower than that of diamond tools, so it has a wide application prospect, especially in cutting non-ferrous metals and fibrous materials. Nanomaterial coating is a recently popularized coating technology that uses various high-performance nanomaterials to form a coating on the surface of hard alloy cutting tools.
Different combinations of nanomaterials can achieve different performance indicators, making them more flexible. It can be used in the high-speed cutting area, but it is still in the experimental research phase and is far from practical applications.
Ceramic Materials:
Ceramic materials are considered advanced materials for cutting tools with high hardness, good wear resistance, low metal affinity, good chemical stability and long service life.
Furthermore, during cutting at high speed and high temperatures, the chips can still be separated from the cutting tool effectively.
Combined with the excellent thermal stability of the ceramic, this reduces the occurrence of cutting accidents, and the roughness of the machined surface of the part is small during the cutting process. This allows “turning instead of grinding”, completing the work of both operations through just one process on a lathe, making it significant for simplifying the process and reducing processing time.
In practical work, commonly used ceramic cutting tool materials include alumina-based ceramics and silicon nitride ceramics.
3.1 Alumina-based ceramic materials
Alumina-based ceramics include alumina ceramics, alumina carbide ceramics, alumina metal ceramics and alumina metal carbide ceramics.
Alumina ceramics are made mainly from alumina and have substances such as nickel oxide added to increase their flexural strength. They perform well at high temperatures and are commonly used for high-speed cutting of hard and brittle materials such as chilled cast iron and hardened steel with high machining precision.
To improve its flexural strength, hardness and toughness, a mixture of metals, carbides, nitrides or various substances is added to alumina ceramics to form ceramic materials.
Among them, alumina-metal-carbide ceramics have the best thermal stability and highest hardness, and can be widely used in the processing of metal materials such as alloy steel, quenched and tempered steel, cast steel, nickel-chromium alloys and non-metallic materials such as fiberglass.
3.2 Silicon nitride ceramic materials
Compared with alumina-based ceramics, silicon nitride-based ceramics have higher strength, fracture toughness and thermal shock resistance, lower coefficient of thermal expansion, Young's modulus and chemical stability. They are not easily bonded to cast iron and are mainly used for high-speed cutting of cast iron.
Diamond Material
Diamonds are known for their extremely high hardness, good thermal stability, and excellent chemical stability, which makes them the best material for bits used in drilling tasks.
Due to their excellent performance, they also have a wide range of applications in high-speed cutting tool materials.
In real life, diamonds that can be used as cutting tools include natural diamonds, artificially synthesized single-crystal diamonds, polycrystalline diamonds, and diamond-coated tools for chemical vapor deposition. Among them, diamond-coated tools were discussed in the previous section.
Natural diamond cutting tools have the potential to become the best tools due to their excellent wear resistance and hardness. They also have extremely high processing precision and can be used to process precision instruments, components such as optical mirrors, chips and more. However, natural diamonds are currently the most expensive type of material for cutting tools.
Single crystal diamonds are diamonds that are artificially synthesized under certain temperature and pressure conditions and are much cheaper to process than natural diamonds. They have good chemical stability and their size and shape are easy to control, which makes them widely used in areas such as mechanical processing, electronic circuit boards, optical glass and wear-resistant flooring.
Polycrystalline diamonds are materials pressed at several thousand degrees Celsius and several hundred megapascals using metallic cobalt as a bonding agent. Their wear resistance is extremely high, making them ideal for processing non-ferrous metals, hard alloys or hard non-metallic materials.
Conclusion
High-speed cutting technology is a magic weapon for machining companies to survive in the fierce market competition. By using high-speed cutting technology, processing speed and accuracy can be significantly improved.
With the continuous development of high-speed cutting technology, the cutting tool materials used in the process will also continue to update and change.
Therefore, it is necessary to choose suitable cutting tools that are in line with current process characteristics and processing requirements and keep pace with the development of science and technology.
We must constantly apply new materials and new technologies in the preparation of high-speed cutting tools, constantly improve tool performance such as higher strength, chemical stability and hardness, and promote the rapid development of the machining industry.
