Application of laser quenching technology for automobile die
1. Most parts in the automobile industry cannot be manufactured without the use of automobile molds. The machining quality and precision of automobile die directly affect the processing quality, processing efficiency and service life of automobile parts. In addition, if the machining quality, strength and hardness of the automobile mould surface cannot meet the requirements, it will also cause damage to the mould surface during clamping and demoulding, thus affecting its service life. In order to improve the mechanical properties of the die surface, a reasonable heat treatment process is needed. Because of the large quenching area, the quenching temperature and cooling degree are not uniform. Therefore, after quenching the surface of automobile molds, there are often hard, fine seam or dent defects, resulting in surface hardness and abrasion resistance not up to the requirements. With the rapid development of laser processing technology, laser quenching as a new surface quenching technology has been developed and applied. Laser quenching technology USES high-energy density laser beam to irradiate the surface of parts for a certain period of time, so that the irradiated parts rapidly heat up and the crystal tissue transformation occurs, the formation of austenite. It then cools quickly, forming a very small layer of high hardening of martensite and other tissues. The surface quenching quality and efficiency are high because the quenching parts absorb heat quickly and the cooling is fast. The surface hardness and abrasion resistance of the mould processed by laser quenching technology are high, and the surface processing quality is high. Because of many advantages, laser quenching technology has been widely used in surface machining of automobile molds.
2. In order to improve the hardness and abrasion resistance of the die surface, the surface of the traditional automobile die is often treated by quenching. The conventional surface treatment technology is usually to directly heat the mold surface which needs to be hardened. When the mould surface is heated for a certain time to reach the predetermined temperature, the hardening treatment of the surface is realized through sharp cooling. This processing technology has the advantages of high efficiency and low cost when it is used to process large and medium-sized molds, and when it does not require high quenching quality on the surface of molds. However, there are many problems in surface quenching of small high quality molds. Because of the poor consistency of quenching, the size of flame, quenching time and quenching distance control are very high. However, once one of the parameters is deviated, the quenching surface will be heated unevenly, and the crystal structure will be changed inconsistently, forming the internal stress. Under the action of internal stress, deformation, crack and depression will occur on the surface of the mould. Finally, the quenching quality of the mould surface is not up to the requirement, which affects its service life.
3. Characteristics of laser surface quenching technology
3.1 scope of application of laser surface quenching technology for die laser surface quenching technology the application of laser surface quenching technology for die surface processing is relatively flexible. It can adjust the direction and Angle of quenching flexibly according to the change of mould surface shape. At the same time, the specific surface can be partially and accurately quenched according to the processing requirements. Because of the laser energy, radiation Angle, time and other control are extremely convenient. As a result, people can fully grasp the quenching mechanism, scientific and reasonable to adjust the parameters of the laser quenching, to ensure that the hardening area and depth, location and the desired effect. At the same time, the laser beam's irradiation time is short, and the energy input to the mold per unit area is small in the process of quenching, so its surface is not easy to generate thermal deformation. In order to control the laser quenching process better and more accurately, people can also write the corresponding laser surface quenching program. Through setting quenching process parameters and scientific of mould surface after quenching organization structure and performance analysis, can be used for modeling quenching process simulation, so as to realize the automation and intelligence of mould laser quenching, speed up the application of laser quenching technique in auto mould direction and development.
3.2 advantages of laser surface quenching technology laser surface quenching technology laser surface quenching technology has many advantages that flame quenching does not have in the process of surface heat treatment of mold. Specifically, it can be divided into the following points:
It has an extremely fast heating and cooling rate. Laser beam has the characteristics of single frequency, good agglomeration and high energy density.
The quenching process can be self-cooled and the quenching deformation is small. Because the laser beam area is narrow, and the energy concentration is uniform.
Torque quenching high hardness, good wear resistance.
Superior surface quality after quenching.
Flow is easy to quench parts and special parts of the surface.
3.3 influence of laser process parameters on the quality of the quenching layer of the mold laser process parameters have a great influence on the quality of the quenching layer of the mold.
4. The application of laser surface quenched by laser quenching has many conventional quenching traditional way that the advantage and characteristic, so the laser surface quenching is now get extensive use in auto mould surface quenching.
5. With the rapid development of automobile industry in recent years, laser surface quenching technology has also been widely used in heat treatment of automobile molds. Related technical research has been deeply involved in the fine tuning control of laser and light guide system, the types of mould materials and crystal structure, quenching mechanism and technical requirements. With the further development of automobile mould material and structure, laser quenching is faced with more and more new situations and problems, and the requirements for laser quenching are higher and higher. For example, how to ensure the reliability of the special laser quenching method under special circumstances; Research on laser quenching technology of high carbon, poor hardenability and fragile mould; How to automatically determine and adjust the parameters of laser quenching process for different materials of molds to ensure the optimal quenching effect; The combination of laser quenching technology and other surface processing technology is also optimized. Gradually with the further development of laser technology and its popularization and application of heat treatment on the surface of the laser quenching technique in auto mould will be more perfect and powerful, it will play a more and more important role.