1. plasma cutting
Plasma cutting is a process in which a high-temperature and high-speed plasma arc is used as a heat source to partially melt the cut metal, and at the same time, the molten metal is blown away by high-speed airflow to form a narrow incision. Hydrogen is used as cutting gas, argon is used as arc initiation gas, and nitrogen is used as vortex gas to cool all parts of the cutting moment and blow off the molten metal.
The advantages of plasma cutting are: fast processing speed and strong processing ability for medium and large plates. However, plasma cutting products need secondary processing, and the arc light generated by cutting is large, and the gas smoke is toxic and pollutes the environment.
2. High pressure water jet cutting
High-pressure water jet cutting is to pressurize ordinary tap water to 250 ~ 400 MPa with a high-pressure cylinder, and then spray it through a gem nozzle with an internal aperture of 0. 15 ~ 0.35 mm to form a high-speed jet with a speed of 800 ~ 1000 m/s, and add a proper amount of sand into the water jet to cut all soft and hard materials. The advantages of water cutting are: almost no heat is generated during cutting, and the product has no thermal deformation, which can ensure the dimensional accuracy of the product; Narrow slit, smooth cutting surface, no need for secondary processing, improving production efficiency; Water cutting can solve the cutting process of some special materials, alloys and composite materials with high melting point. However, due to the tolerance error caused by the lag of water jet arrow and the oblique angle of incision, for parts with a certain thickness (above 40mm) or high precision requirements, the best effect can not be achieved by water jet machining.
3. Laser cutting
Laser cutting is a new processing technology, which has been widely used in metal cutting, glass cutting, carving and other industries. Laser is a kind of light, which is produced by the transition of atoms (molecules or ions, etc.). ), but unlike ordinary light, it only depends on spontaneous radiation in the initial short time, and the subsequent process is completely determined by laser radiation, so laser has high coherence, high intensity and high directivity. After the laser generated by the laser cutting machine is transmitted by the reflector and irradiated on the processed object through the condenser, the processed object (surface) is subjected to intense heat energy, and the temperature rises sharply.
The advantages of laser cutting machine are: there is no mechanical pressure on the workpiece, so the cut product has high precision and does not need secondary processing; Fast cutting speed, simple operation and high degree of automation; Products with any complex shape can be cut, which is usually better than stamping and molding. Although the processing speed is slower than punching and cutting, the die cost is saved and the economic cost is low. However, for aluminum alloy plates with a thickness of more than 6mm, the cutting effect is not good when laser processing is used, the equipment has high requirements for the use environment, and the maintenance time is long after the equipment fails.
4. Conclusion
Three different blanking methods have their own advantages and disadvantages. After several years of application, it has been stably used in mass production of aluminum alloy parts for urban rail vehicles and achieved good results.