威廉希尔官方下载Apr 11, 2020
Laser welding of precision parts is carried out by using the laser beam focused by high power coherent monochromatic photon flow as the heat source. This welding method usually includes continuous power laser welding and pulse power laser welding. The advantage of laser welding is that it does not need to be carried out in a vacuum, but the disadvantage is that the penetration force is not as strong as that of electron beam welding.
The laser welding of precision parts can control the energy precisely, so it can realize the welding of precision microdevices. It can be applied to many metals, especially to some difficult to weld metals and dissimilar metals.
Generation of welding laser for precision parts: the same wavelength, frequency, and direction of the light beam generated when the material is excited.
The characteristics of laser welding for precision parts: it has good monochromaticity, good directivity, and high energy density. After the laser is transmitted or focused by the mirror, the energy beam with a diameter of less than 0.01mm and power density up to 1013w / cm2 can be obtained, which can be used as the heat source for welding, cutting, drilling, and surface treatment. Laser materials include solid, semiconductor, liquid, gas, etc. among them, YAG solid laser and CO2 gas laser are mainly used in welding, cutting, and other industrial processes.
The main advantages of laser welding for precision parts are:
(1) The laser for precision parts welding can be bent and transmitted by optical methods such as optical fiber and prism. It is suitable for the welding of micro parts and other parts that are difficult to be achieved by other welding methods. It can also be welded by transparent materials.
(2) With high energy density, it can realize high-speed welding, and the heat-affected zone and welding deformation are very small, especially suitable for the welding of heat-sensitive materials.
(3) Laser welding of precision parts is not affected by the electromagnetic field, does not produce X-ray, does not need vacuum protection, and can be used for welding of large structures
(4) It can directly weld the insulated conductor without stripping the insulating layer in advance, and can also weld the dissimilar materials with different physical properties.
The main disadvantages of laser welding for precision parts are expensive equipment, low energy conversion rate (5% - 20%), high requirements for welding interface processing, assembly and positioning. At present, it is mainly used for the welding of microdevices in electronic industry and instrument industry, as well as the welding of silicon steel sheet and zinc-plated steel plate.