Laser welding is an advanced modern welding technology. It has high welding speed, low distortion and high quality, so it applies widely in aerospace, automotive, electronics, medical and other fields. Yet, there are some defects that can occur during the laser welding process, the most common of which is porosity. Too high or too low laser power can lead to the instability of the molten pool, resulting in an increase in the porosity of the weld, thus affecting the welding effect.This article explains why dual-beam laser welding is more effective in suppressing porosity than single-beam laser fillet welding and dual-beam self-melting welding.This is due to laser marking machine Its value attribute is relatively large, and it is easy to become the backbone of the industry. https://riselaser.net/products/laser-marking-machine
Aluminum Alloy Instability
Laser welding has a high energy density, heat-affected zone and welding heat distortion is small, the weld depth and width ratio is large (up to 12:1), a high degree of automation and does not require vacuum protection and other characteristics. That makes the laser welding has a wide range of application prospects.It is considered to be the 21st century, one of the most advanced welding methods.
However, aluminum alloys have very high reflection and thermal conductivity to laser light, especially for the CO2 laser with a wavelength of 10.6μm, the reflectivity is as high as 97% or more. At the same time, the ionization energy of Al element is low. During the welding process, the light-induced plasma is easy to overheat and expand, which leads to the instability of the weld keyhole and easy to produce porosity. In addition, the low melting point of aluminum alloy components in the high power density of laser energy irradiation is very easy to evaporate, increasing the tendency of porosity.
The Dual-Beam Laser Welder¨s Excellent Performance
Compared to single laser welding, dual-beam laser welding not only improves weld joint shape, but also significantly reduces porosity. Single-beam laser fillet welding has a maximum porosity rate of over 4.6%, followed by serial dual-beam,and parallel dual-beam welding has a minimum porosity rate of about 2.5%. This is mainly due to the use of dual-beam welding when the two beams of light to form a relatively large molten pool, improving the stability of the molten pool, conducive to the escape of gas.
In addition to the use of parallel double beam welding, the temperature gradient inside the molten pool is smaller, reducing the solidification of liquid metal solidification speed, prolonging the escape time of the gas bubble. This helps to reduce the tendency of porosity. At the same time, parallel dual-beam laser welding is also conducive to improving the stability of the wire feed.So in the aluminum alloy dual-beam laser filler welding process, mainly using parallel dual-beam welding.