Views: 99 Author: Site Editor Publish Time: 2022-06-11 Origin: Site
Aluminum alloy materials have high strength and good mechanical properties, and are widely used in life and industrial production. The aluminum alloy laser welding process is a new generation welding method with laser as a high energy density light source. It has the advantages of fast heating and high efficiency.
However, due to the very high thermal conductivity and reflectivity of aluminum alloy materials, as well as its own plasma shielding effect, some technical problems are prone to occur during the aluminum alloy laser welding process, which affects the welding effect, which also makes the aluminum alloy laser welding process becomes more complicated and needs to be solved and improved through certain technical means.
When laser welding aluminum alloy, because the aluminum alloy material has an important high reaction to the laser, it is necessary to carry out appropriate surface pretreatment work on the aluminum alloy material, such as sandblasting,anodizing, electropolishing, etc. , it can significantly improve the absorption of the laser beam energy on the surface of the aluminum alloy material. Studies have shown that the tendency of crystallization cracking of aluminum alloy material after removing the oxide film will be larger than that of the original aluminum alloy material. Therefore, in order to ensure that the surface state of the aluminum alloy material is not damaged, and the purpose of simplifying the laser welding engineering process can be achieved, the method of pre-welding can be used to increase the surface temperature of the aluminum alloy workpiece, so as to improve the laser energy of the aluminum alloy material absorption and conversion rates.
Aluminum alloy laser welding lasers are divided into two types: pulsed lasers and continuous lasers. When the wavelength of the pulsed laser is 1064nm, the laser beam is very concentrated and focused, and the single-point energy of the pulse is larger than that of the continuous laser.
Due to the high reflectivity of the aluminum alloy surface to light during aluminum alloy laser welding, when the high-intensity laser beam hits the surface of the aluminum alloy material, about 60-98% of the laser energy on the surface will be lost due to reflection, and The light energy reflectivity of aluminum alloys varies with the surface temperature of the workpiece. Therefore, in general, sharp wave and double peak wave are the best choices for laser welding of aluminum alloys, and in the rising stage of the waveform, it is to provide greater energy to melt the surface of the aluminum alloy. If the "small hole" in the workpiece is formed, when the deep penetration welding is started, the liquid state of the aluminum alloy material will rapidly increase the absorption rate of the laser beam. Beam welding to avoid liquid splash.
The above are the precautions for aluminum alloy laser welding. If you have questions about laser equipment, you are welcome to consult us at any time.