Mar 31, 2020
The laser processing or forming according to certain requirements through the interaction with materials is collectively referred to as optical manufacturing. In the past 20 years, optical manufacturing technology has penetrated into high-tech fields and industries and began to replace or transform some traditional processing industries. In the automobile industry of developed countries, 50% - 70% of the parts are processed by laser. Optical manufacturing technology is playing an increasingly important role in improving the R & D and manufacturing level of the automobile industry.
1. Characteristics of optical manufacturing technology
At present, the laser is the main optical source used in the optical manufacturing technology. The laser beam has the characteristics of high energy density, high single palladium, and high directivity, which makes the optical manufacturing technology have many advantages that traditional manufacturing techniques cannot. The tool used in this technology is "laser cutter", which has no tool wear during machining; there is no influence of cutting force on the workpiece during machining, so the workpiece has no cold machining deformation; due to the high speed of energy injection during machining, the thermal impact on the workpiece is very small, so the workpiece has very small thermal deformation, which can approach or reach the "cold" machining state, so as to realize the high-precision manufacturing that cannot be performed by conventional technology; exciting optical has good space control (beam direction change, rotation, scanning, etc.) and time control (on, off, pulse interval), especially suitable for automatic processing, with high production efficiency in large-scale manufacturing; the material, shape, size and freedom of processing environment of laser processing object are very large; the noise is low, no harmful rays and residues are produced, and the production process It can save mould, shorten the period of product development and reduce the cost of development. It has less waste of materials and low cost of manufacturing in large-scale production.
1. Category of optical manufacturing technology in the automobile industry
Optical manufacturing technology in the automobile industry can be divided into three categories: optical "cold" processing, optical "hot" processing, and optical rapid prototyping.
A. Optical "cold" processing technology
Laser cutting, laser drilling, laser marking, and laser cutting are the optical manufacturing technologies corresponding to the conventional cold processing technology.
The laser cutting speed is fast, the incision is smooth and flat, the trimming parallelism is good, no procurement follow-up processing; the slit is narrow; the incision has no mechanical stress, no shear burr; the processing accuracy is high, the repeatability is good, and the workpiece surface is not damaged.
Laser drilling has the advantages of high speed and efficiency, which is suitable for group hole processing with large quantity and high density; laser drilling can obtain a large depth diameter ratio, which can be processed on various materials such as hard, brittle and soft materials, and can even process small holes on the inclined surface of difficult to process materials; the process of laser drilling is clean and pollution-free.
Laser marking is non-contact marking, which is fast and not easy to wear. The laser marking machine is easy to combine with assembly line.
Laser cutting is a kind of technology similar to milling in machining. It uses a focused laser beam to cut material layer by layer.
B. Optical "hot" processing technology
Laser welding, laser surface strengthening, laser cladding, and alloying are the corresponding optical manufacturing technologies.
Laser welding is a process in which the metal to be welded is locally heated to the melting temperature by a high-intensity laser beam. It can weld special materials such as high melting point metal, non-metal, composite material, etc. it can also realize the welding of different materials and special structures. The weld has the function of "self-purification", and the weld quality is high. It can carry out precise welding, generally without filling metal. Through the light guide system, the laser beam and multiple types of equipment form a flexible processing system, and the welding has high automation and production efficiency In high energy beam welding, the biggest characteristic of laser welding is that it does not need a vacuum chamber and does not produce X-ray.
Laser surface hardening can be divided into laser transformation hardening and laser melting hardening. Laser transformation hardening, also known as laser hardening, is a rapid scanning of workpieces with the high-energy laser beam, which makes the surface temperature of the irradiated metal or alloy rise to above the phase point at an extremely fast speed. When the laser beam leaves the irradiated part, due to the heat conduction, the matrix in the cold state makes it cool rapidly and self-cooling quenching is carried out to obtain the finer hardening layer structure, which is generally high in hardness The laser melting hardening process is similar to the previous process. The difference is that the laser makes the heating temperature of the material surface higher, and the final part surface forms a fine flame hardening layer.
Laser cladding is a kind of alloy cladding with completely different compositions and properties, which is formed by the rapid solidification of the cladding material with the substrate surface thin layer by irradiating the cladding material with a high energy laser beam.
C. Optical rapid prototyping technology
The principle of optical rapid prototyping technology is the process of using a laser beam to solidify the molding materials layer by layer according to the CAD design model and data of the parts, constructing the surface (layer) of the parts from points and lines, and accurately stacking the surface into three-dimensional solid model or parts under the control of the computer. By using the optical rapid prototyping technology, the product development cycle can be significantly shortened, the development cost can be greatly reduced, the products that adapt to the market changes can be produced rapidly, and the competitiveness of products in the market can be maintained and strengthened. At the same time, the use of optical rapid prototyping technology is also an effective way to achieve concurrent engineering and agile manufacturing.
In the new century, the automobile industry is stepping into the lean production stage which can carry out flexible processing according to the user's requirements. The flexible modular production mode appears in the automobile industry. The modern automobile industry is also developing towards the direction of high-tech. the automobile technology is undergoing the transformation from the traditional mechanical manufacturing technology to advanced manufacturing technology. Light manufacturing technology has injected vitality into the development and production of the automobile. It can be predicted that the application of light manufacturing technology in the automobile industry will develop rapidly in this century, and will become an important processing method in the automobile industry.