Laser technology using polariscope reflected laser beam makes it focused on the result in huge energy beam focusing device, if the focus close to the workpiece, workpiece will be melting and evaporation in milliseconds, this effect can be used for welding "ecomax" power CO2 and the emergence of high power YAG laser, has opened up a new field of laser welding.
Laser welding equipment is the key to high-power lasers, there are two main categories, one is the solid laser, also known as Nd:YAG laser.Nd (neodymium) is a rare earth element, YAG stands for yttrium aluminum garnet, and its crystal structure is similar to ruby.Nd:YAG laser wavelength is 1.06μm, the main advantage is that the beam can be transmitted through the optical fiber, so it can save to the complex beam transmission system, suitable for flexible manufacturing system or remote processing, usually used for welding precision requirements of the workpiece.
Nd:YAG lasers with output power of 3-4 kW are commonly used in automobile industry.The other kind is gas laser, also known as CO2 laser, molecular gas as the working medium, produce uniform 10.6μm infrared laser, can work continuously and output very high power, the standard laser power between 2-5 kW.
Main advantages:
1. fast speed, large depth, small deformation.
2. It can weld at room temperature or under special conditions. The welding equipment is simple.For example, when a laser passes through an electromagnetic field, the beam does not deviate;The laser can weld in vacuum, air and certain gas environments, and can weld through glass or materials transparent to the beam.
3. can weld refractory materials such as titanium, quartz, etc., and can weld the opposite materials, good effect.
4. After laser focusing, the power density is high. When welding high-power devices, the ratio of depth to width can reach 5:1 and the maximum can reach 10:11
5. can be micro welding.The laser beam can obtain a small spot after focusing, and can be precisely located, which can be applied to the assembly welding of micro and small workpiece produced by mass automation.
6. can weld the parts that are difficult to access, the implementation of non-contact distance welding, with great flexibility.Especially in recent years, optical fiber transmission technology has been used in YAG laser processing technology, which makes laser welding technology more widely promoted and applied.
7. the laser beam is easy to achieve light beam according to time and space splitting, can carry out multi-beam processing and multi-station processing at the same time, provides conditions for more precise welding.
However, laser welding also has certain limitations:
1. It is required that the assembly accuracy of welding parts is high, and the position of light beam on the workpiece can not have obvious deviation.This is because after laser focus, the light spot size rain inch is small, the weld is narrow, and the metal material is filled.If the workpiece assembly accuracy or beam positioning accuracy can not meet the requirements, it is easy to cause welding defects.
2. the cost of laser and related systems is high, one-time investment is large.
