Nowadays, diamond cutting tools are widely used, with advantages such as high hardness and wear resistance, low friction coefficient, high elastic modulus, high thermal conductivity, low coefficient of thermal expansion, and low affinity with non-ferrous metals. It can be used for precision machining of non-metallic hard and brittle materials such as graphite, high wear-resistant materials, composite materials, high silicon aluminum alloys, and other ductile non-ferrous metal materials. There are various types of diamond cutting tools, with significant differences in performance. There are significant differences in the structure, preparation methods, and application fields of different types of diamond cutting tools. Perhaps many people want to learn more about diamond cutting tools. Below, we will introduce in detail the types, performance characteristics, applications, manufacturing methods, the impact of tool tip geometry on the quality of ultra precision cutting, and tips for improving durability of diamond cutting tools.
Nowadays, diamond cutting tools are widely used, with advantages such as high hardness and wear resistance, low friction coefficient, high elastic modulus, high thermal conductivity, low coefficient of thermal expansion, and low affinity with non-ferrous metals. It can be used for precision machining of non-metallic hard and brittle materials such as graphite, high wear-resistant materials, composite materials, high silicon aluminum alloys, and other ductile non-ferrous metal materials. There are various types of diamond cutting tools, with significant differences in performance. There are significant differences in the structure, preparation methods, and application fields of different types of diamond cutting tools. Perhaps many people want to learn more about diamond cutting tools. Below, we will introduce in detail the types, performance characteristics, applications, manufacturing methods, the impact of tool tip geometry on the quality of ultra precision cutting, and tips for improving durability of diamond cutting tools.
Types of diamond cutting tools
1. Natural diamond cutting tools:
Natural diamond has a history of over a hundred years as a cutting tool. After fine grinding, natural single crystal diamond tools can have extremely sharp edges, with a cutting radius of up to 0.002 μ m. Being able to achieve ultra-thin cutting and achieve extremely high workpiece accuracy and low surface roughness, it is a recognized, ideal, and irreplaceable ultra precision machining tool.
2. PCD diamond cutting tools:
Natural diamond is expensive, and polycrystalline diamond (PCD) is still widely used in cutting. Since the early 1970s, polycrystalline diamond (PCD) blades, which were prepared using high-temperature and high-pressure synthesis technology, have been successfully developed. In many cases, natural diamond cutting tools have been replaced by artificial polycrystalline diamond. PCD has a rich source of raw materials, and its price is only a few tens to ten times that of natural diamond. PCD tools cannot grind extremely sharp edges, and the surface quality of processed workpieces is not as good as natural diamonds. Nowadays, PCD blades with chip breaking grooves are also manufactured in industry. Therefore, PCD can be used for precision cutting of non-ferrous metals and non-metals, but it is difficult to achieve ultra precision mirror cutting.
3. CVD diamond cutting tools:
Since the late 1970s to early 1980s, CVD diamond technology has emerged. CVD diamond refers to a diamond film synthesized by chemical vapor deposition (CVD) on heterogeneous substrates such as hard alloys, ceramics, etc. CVD diamond has the same structure and characteristics as natural diamond. The performance of CVD diamond is very similar to that of natural diamond, and it combines the advantages of natural single crystal diamond and polycrystalline diamond (PCD), which to some extent overcomes their shortcomings.
Performance characteristics of diamond cutting tools
1. Extremely high hardness and wear resistance:
Natural diamond is the hardest substance discovered in nature. Diamond has extremely high wear resistance. When processing high hardness materials, the lifespan of diamond cutting tools is 10-100 times that of hard alloy cutting tools, and even hundreds of times longer.
2. Has a very low coefficient of friction:
The friction coefficient between diamond and some non-ferrous metals is lower than that of other cutting tools. The friction coefficient is low, and the deformation during processing is small, which can reduce cutting force.
3. The cutting edge is very sharp:
The cutting edge of diamond cutting tools can be ground very sharp, and natural single crystal diamond cutting tools can reach as high as 0.002-0.008 μ m. Capable of ultra-thin cutting and ultra precision machining.
4. Has high thermal conductivity:
Diamond has a high thermal conductivity and thermal diffusion rate, making it easy for cutting heat to dissipate, and the cutting temperature of the tool is low.
5. Has a lower coefficient of thermal expansion:
The thermal expansion coefficient of diamond is several times smaller than that of hard alloy, and the change in tool size caused by cutting heat is very small, which is particularly important for precision and ultra precision machining with high dimensional accuracy requirements.
The application of diamond cutting tools
1. Difficult to process non-ferrous metals
When processing non-ferrous metals such as copper, zinc, aluminum, and their alloys, these materials adhere to the cutting tool and are not suitable for processing. Diamond cutting tools made by utilizing the low friction coefficient and low affinity with non-ferrous metals can prevent the metal from sticking together with the tool. Due to the high elastic modulus of diamond, the deformation of the cutting edge is small during cutting, and the extrusion deformation of the cut non-ferrous metal is small, allowing the cutting process to be completed under small deformation, which can improve the surface quality of cutting.
2. Difficult to process non-metallic materials
When processing difficult to machine non-metallic materials containing a large number of high hardness particles, such as glass fiber reinforced plastics, silicon filled materials, and hard carbon fiber/epoxy resin composite materials, the hard points of the materials cause severe tool wear, making it difficult to machine with hard alloy tools, while diamond tools have high hardness and good wear resistance, resulting in high processing efficiency.
3. Ultra precision machining
With the emergence of modern integrated technology, machining is developing towards high precision, which puts forward quite high requirements for tool performance. Due to the small friction coefficient, low thermal expansion coefficient, and high thermal conductivity of diamond, it can cut extremely thin chips, which are easy to flow out and have a low affinity with other substances, making it less prone to chip accumulation. The heat generation is low, and the thermal conductivity is high, which can avoid the influence of heat on the cutting edge and workpiece. Therefore, the cutting edge is not easy to passivate, the cutting deformation is small, and a high-quality surface can be obtained.
The application of diamond cutting tools
1. Difficult to process non-ferrous metals
When processing non-ferrous metals such as copper, zinc, aluminum, and their alloys, these materials adhere to the cutting tool and are not suitable for processing. Diamond cutting tools made by utilizing the low friction coefficient and low affinity with non-ferrous metals can prevent the metal from sticking together with the tool. Due to the high elastic modulus of diamond, the deformation of the cutting edge is small during cutting, and the extrusion deformation of the cut non-ferrous metal is small, allowing the cutting process to be completed under small deformation, which can improve the surface quality of cutting.
2. Difficult to process non-metallic materials
When processing difficult to machine non-metallic materials containing a large number of high hardness particles, such as glass fiber reinforced plastics, silicon filled materials, and hard carbon fiber/epoxy resin composite materials, the hard points of the materials cause severe tool wear, making it difficult to machine with hard alloy tools, while diamond tools have high hardness and good wear resistance, resulting in high processing efficiency.
3. Ultra precision machining
With the emergence of modern integrated technology, machining is developing towards high precision, which puts forward quite high requirements for tool performance. Due to the small friction coefficient, low thermal expansion coefficient, and high thermal conductivity of diamond, it can cut extremely thin chips, which are easy to flow out and have a low affinity with other substances, making it less prone to chip accumulation. The heat generation is low, and the thermal conductivity is high, which can avoid the influence of heat on the cutting edge and workpiece. Therefore, the cutting edge is not easy to passivate, the cutting deformation is small, and a high-quality surface can be obtained.