How to choose the right tool for machining?

In fact, in machining, the choice of which tool to use is mainly determined by the material to be processed and the processing properties. This improves not only machining efficiency and machining quality, but also tool life.

The workpiece material with high hardness needs to be machined with a higher hardness tool, so the hardness of the tool material must be higher than that of the workpiece material.

The higher the hardness of the tool material, the better its wear resistance. For example, when the drill content in cemented carbide increases, its strength and initial properties increase, and its hardness decreases, which is suitable for rough machining: when the drill content decreases, its hardness and wear resistance increase, which is suitable for machining tools with excellent high-temperature mechanical properties. , especially suitable for high-speed cutting.

Generally speaking, PCBN, ceramic cutting tools, coated cemented carbide and TCN-based cemented carbide cutting tools are suitable for processing metals such as steel; PCD cutting tools are suitable for processing non-ferrous materials such as AlMg, Cu and their alloys and non-metallic materials. .

Specifically, cubic boron nitride is suitable for finishing various hard-to-cut materials such as hardened steel, hard cast iron, superalloy, cemented carbide, and surface sprayed materials. Diamond tools are suitable for processing various wear-resistant non-metals, such as glass fiber reinforced plastic powder metallurgy blanks, ceramic materials, etc.; various wear-resistant non-ferrous metals, such as various silicon aluminum alloys; various non-ferrous metals finishing. Ceramic tools are suitable for machining all kinds of cast iron (gray cast iron, ductile iron, malleable cast iron, chilled cast iron, high alloy wear-resistant cast iron) and steel (carbon structural steel, alloy structural steel, high strength steel, high manganese steel, hardened steel etc.), can also be used to cut copper alloys, graphite, engineering plastics and composite materials. Coated tools meet the needs of high-speed machining of various steel and cast iron, heat-resistant alloys and non-ferrous metals. Carbide is mainly used for machining cast iron, non-ferrous metals and non-metallic materials.

For your better understanding, the following table has been compiled:

However, in addition to tool selection, processing methods are also very important, especially for some unconventional cutting methods, which are very important for some difficult-to-machine materials. Let's take a look at five types of cutting methods.

One of the heating cutting methods is conductive heating cutting, which generates heat in the cutting area, reduces its hardness and strength, and improves cutting conditions.

Low temperature cutting method, using liquid nitrogen (-180 ℃) or liquid CO2 (-76 ℃) as the cutting fluid, can reduce the temperature of the cutting area, using this method can reduce the main cutting force by 20%, and the cutting temperature can be reduced by more than 300 ℃

Hauke ​​energy processing, Haoke energy is a kind of energy processing method, which uses the composite energy of activation energy and impact energy to process metal parts, which can make the surface of the parts mirror and realize the innovative energy processing technology of modification in one processing. .

In the ultra-high-speed cutting method, under conventional cutting, increasing the cutting speed will reduce the tool durability. This cutting method is often restricted by equipment conditions and cannot be promoted. Whether it can play a role in the cutting of difficult-to-machine materials remains to be discussed.

Special machining methods, such as EDM, electrolytic machining, ultrasonic machining, laser machining, electron beam machining, ion beam machining, etc. are called special machining methods.