Deep penetration welding can also be called deep penetration welding. This process can not only completely melt the material, but also vaporize the material to form a large amount of plasma. Due to the large heat, a keyhole phenomenon will appear at the front of the molten pool. Deep penetration welding can completely penetrate the workpiece, and has large input energy and fast welding speed. It is currently the most widely used laser welding mode. Now, let's take a look at the main factors that affect the effect of deep penetration welding with Foshan Fulan Laser.

1. Shielding gas

The role of the shielding gas is to remove the air in the local area of the welding and protect the working surface from oxidation; the other is to suppress the generation of plasma clouds during high-power laser welding. Laser welding machines often use inert gas to protect the molten pool. When certain materials are welded, the surface oxidation may not be considered, but the protection may not be considered. However, for most applications, helium, argon, nitrogen and other gases are often used as protection to make the workpiece in Avoid oxidation during welding.

2. Laser power

The prerequisite for deep penetration welding is to focus the laser spot so that it has a sufficiently high power density, so the laser power density has a decisive influence on the weld formation. The laser power controls the penetration depth and welding speed at the same time. Generally speaking, for a laser beam with a certain diameter, the penetration depth increases as the beam power increases. When the laser power is increased, the penetration deepens and the welding speed increases.

3. Welding speed

The welding speed has a great influence on the penetration depth. Increasing the speed will make the penetration shallower, but if the speed is too low, it will cause excessive melting of the material and weld penetration of the workpiece. In the process of deep penetration welding, the welding speed is inversely proportional to the penetration depth. Therefore, there is a suitable welding speed range for certain laser power and certain thickness of certain materials, and the penetration depth can be obtained at the corresponding speed value.

4. Focus position

In deep penetration welding, in order to maintain sufficient power density, the focus position is very important. The change of the relative position of the focal point and the surface of the workpiece directly affects the width and depth of the weld. Only when the focal point is located at a suitable position on the surface of the workpiece, can the resulting weld form a parallel section and obtain the maximum penetration depth.

5. Material absorption value

The absorption of laser light by a material depends on some important properties of the material, such as absorptivity, reflectivity, thermal conductivity, melting temperature, evaporation temperature, etc. The most important of which is absorptivity. The factors that affect the material’s absorption rate of the laser beam include two aspects: First, the material’s electrical resistivity. After measuring the absorptivity of the polished surface of the material, it is found that the material’s absorptivity is proportional to the square root of the electrical resistivity, and the electrical resistivity varies with temperature. And change; secondly, the surface state (or smoothness) of the material has a more important influence on the beam absorption rate, which has a significant effect on the welding effect.

6. The gap between the workpiece and the joint

The gap between the workpiece and the assembly gap is directly related to the penetration depth of the welding workpiece and the width of the welding seam. In deep penetration welding, if the joint gap exceeds the spot size, it cannot be welded; if the joint gap is too small, sometimes the process will produce undesirable effects such as overlapping of the joint plates and difficulty in fusion; if the joint gap is too large, it is easy to weld through; slow speed Welding can make up for some weld defects caused by excessive gaps, while high-speed welding narrows the weld seam, which requires more stringent assembly.

Nowadays, in industrial manufacturing, laser welding is gradually replacing the traditional welding process. Although the input cost of laser welding equipment is higher than that of traditional welding equipment, due to the performance and efficiency of laser welding, it has become a favorite machine and equipment of many companies. The matter must first be sharpened."