There are many methods for laser welding products, which vary depending on the product. Below, the editor of Guangzhou Laise Laser has compiled several commonly used welding methods.

1、 Welding method of wire to wire



Welding between fine wires is relatively difficult, and dragon is a type of fine wire welding with a diameter of 0.01-0.1mm. Pulse laser spot welding has achieved good results and demonstrated its unique advantages.



(1) Welding of wires and wires. Compared with sheet shaped components, there is a significant gap in thermal conductivity in the welding of filamentous components. The sheet elements around the solder joint have good thermal conductivity conditions in all directions and a wide range of welding parameters. But the welding of the wire only transfers heat along the direction of the wire, and the laser parameters need to be strictly controlled. The finer the metal wire, the stricter the parameters, and the higher the stability requirements of the equipment. In the welding of fine wires, the gap requirement is very high, and the finer the wire, the smaller the gap requirement. Due to the filling of gaps with molten metal, even without gasification, the molten zone will become finer and the strength will decrease. In practical work, this strict clearance requirement is difficult to ensure thickness. Therefore,



(2) Cross welding. Two metal wires intersect in a cross shape, and the laser simultaneously illuminates the intersection of the wires, causing them to melt simultaneously. If the diameters of two wires are different, the fine wires should be placed on the upper layer to achieve good welding results with less energy.



(3) Parallel lap welding. Two metal wires are placed parallel, and the laser simultaneously illuminates the overlapping part to melt both wires simultaneously. This welding method is similar to the seam welding between sheets, and the requirements for the workpiece are similar to the welding between sheets. If it is necessary to increase the strength, the overlapping part can be added and more welding points can be welded if the process allows.



(4) T-shaped welding. Some welding methods are similar to cross welding, but are more flexible. In addition to placing two wires on T-shaped and F-shaped surfaces, laser can also simultaneously irradiate both wires to form a molten connection zone, and take some measures according to the specific situation to improve the welding effect. For example, wrapping thin threads around thick threads and welding the wound area. If the diameter difference between two wires exceeds 5 times, and the diameter of the fine wire is very small, laser drilling can be used to thread the fine wire through the small hole, spheroidize the end of the fine wire, and finally weld the fine wire ball with the thick wire in the small hole. By using this process method, not only is the welding part smooth, but also the strength is good.

2、 Welding method between sheets



(1) End welding. Two pieces of metal are placed overlapping, and the laser simultaneously illuminates the joints at the upper and lower ends, forming a molten pool at the metal joint. Compared to welding, the precision requirements for workpiece machining dimensions are lower and easier to achieve, especially in airtight seam welding. During end welding, press the top and bottom tightly, and the gap should be less than 25% of the penetration depth. Thin sheets should be placed on top. If the thick plate is on top, the chamfer at the upper end can be 45-60 degrees.



(2) Welding. Two pieces of metal are placed together, and the laser directly irradiates the two pieces of metal. The irradiated part melts into the joint, and the melted parts of the two pieces of metal solidify to form a welding area. This welding method is easy to implement and the welding effect can be directly observed, which is often used. It requires small weld gaps and small height differences. When the weld gap is less than 15% of the penetration depth and the height difference is less than 25% of the penetration depth, the welding effect is better. Exceeding the above values can easily cause cracks along the direction of the weld seam.



(3) Center piercing fusion welding. The welding method is basically the same as center penetration fusion welding, but in the early stage of laser pulses, the material evaporates at the light center to form small holes. In the middle and late stages of laser pulses, light is directly directed through small holes to the depths of the material. This welding method is mainly used for thicker upper metal materials and is suitable for spot welding, not for airtight seam welding.



(4) Center penetration fusion welding. Two types of metals overlap, and the laser only illuminates the upper part. Light energy is transmitted through thermal conduction to the upper and lower metals, forming a melting pool. This method is more suitable for the upper layer material than thin sheets because the laser power (energy) required to achieve good fusion welding is smaller. If starting from the part manufacturing process, thick sheets must be placed on the upper layer of material to achieve deeper penetration welding, which can increase the power density of the material surface and generate a certain amount of evaporation.