Hobby & Industrial Laser Welders for Metal Joints: Which One To Buy?

Laser welder features with deep penetration, high speed, high precision, and easy remote control and automation. From low-precision metal sheet connection to high-precision auto parts, and emerging new energy battery manufacturing, it is omnipotent. We have been surrounded by laser welding machines in our daily life and modern industrial manufacturing. Are you looking to get your own laser welder? Here is right place, you can learn more from this beginner's guide, and compare from our best selection of popular welders listed below. Let's jump right into this guide.

What Is It and How Does It Work?

A laser welding machine is an efficiency and precise welder that focuses a high-energy laser beam on a welding wire to heat and melt it to fill the gap between two metal joints, and finally form a precise weld to achieve a firm connection. After laser welding, the brazing connection between the welding wire and the metal part is formed. The welding wire and the metal are different elements, and the welding layer formed by it is the fusion of two different elements after high temperature. Compared with traditional spot welder, this welder features with better quality, faster speed and higher strength of welding parts.

Types of Welding

Laser Brazing

Laser brazing uses a material with a lower melting point than the base metal as the filler metal (called brazing material). After heating and melting, the liquid solder is used to wet the base material, fill the gap between the joints and diffuse with the base material , to achieve the soldering method of the connection. Laser brazing process is applied to welding, which not only makes the product more beautiful and improves the sealing, but also significantly improves the strength of the welding area. The connection method of the base metal belongs to the crimping butt joint.

Laser Fusion Welding

At the corner joint of the two plates, part of the base metal of the two plates is melted (at the same time, the nearby welding wire is melted to fill the corner joint of the two plates) to form liquid metal. After cooling, it forms A welding method for a reliable connection. Laser fusion welding can be divided into penetration welding, fusion welding (without filler wire) and fusion filler wire welding. The base metal connections are lap joints.

Laser On-Fly Welding

Laser on-fly welding is also known as remote laser 3D welding or robotic laser scan welding. It comes with a high-speed scanning mirror (often referred to as "vibrating mirror") scanning head on the sixth axis of the robot, and realizes the laser trajectory movement only through the swing reflection of the mirror, without the need for the robot arm to follow the movement. Laser remote welding system is highly flexible and more efficient than ordinary laser welding. One system can replace 6 to 9 sets of ordinary robot spot welding. The distance between the laser head and the workpiece is more than 500mm, which can prolong the service life of the lens protection glass. The process principle is the same as that of fusion welding, which is a form of plate lap joint.

Compared with traditional welding, the biggest advantage of laser remote welding is that it can improve production efficiency. The fast lens movement of the scanning head greatly reduces the time for positioning the robot arm, thereby greatly shortening the manufacturing time. Compared with resistance spot welding, the average 0.5 Compared with the speed of welding spots/s, the welding speed is 3~4 welding spots/s, which makes full use of the laser beam. Through mass production testing, compared with traditional resistance spot welding, the time of laser remote welding can be shortened by 80%. Taking Volkswagen as an example, the company's traditional resistance spot welding process uses 4 robots, 5 welding torches, and a total of 34 welding spots. Adding the loading and unloading time, it takes a total of 34.7 s. Now laser scanning welding is used to complete the same work, that is, 34 solder joints, and the solder joint shape is C-type (C-type solder joints are stronger than round-type solder joints), only one robot and one PFO are needed, and the time is shortened to 13 s.

Compared with traditional spot welding, laser on-fly welding can customize the weld form, optimize the weld strength and increase the flexibility of design, and can be applied to any weld form and any weld direction.

Laser Hybrid Welding

Laser hybrid welding refers to laser and MIG arc hybrid welding. The laser and the arc interact and learn from each other. This technology does not act on the two welding methods in sequence, but the two methods act on the welding area at the same time. Laser and arc affect the performance of hybrid welding in different degrees and forms.

Laser welding is a high-efficiency and precise welding tool that uses a high-energy-density laser beam as a heat source, but this process requires that the beam and the size of the welding seam maintain a corresponding consistency. In contrast, gas metal arc welding is better at dealing with inconsistent gap sizes. Therefore, laser hybrid welding is a process that combines laser nugget gas welding with each other, so as to achieve the ideal welding effect.

Pros and Cons

Pros

• Small heat affected zone. The heat input can be reduced to the minimum required, and the heat affected zone is small, so the thermal deformation is also minimal.

• Contactless. It can be welded when it is visible, which belongs to non-contact welding, does not need to use electrodes, there is no concern about electrode pollution or damage, and the wear and deformation of the machine can also be minimized.

• A laser beam is easily focused, aligned and guided by optics, can be placed at an appropriate distance from the workpiece, and can be guided between tools or obstacles around the workpiece.

• A laser beam can be focused on a small area to automatically weld small, closely spaced components.

• It is easy to realize high-speed automatic welding by numerical control.

Cons

• The position of the weldment needs to be very precise and must be within the focal range of the laser beam.

• The maximum weldable thickness is limited by the penetration thickness, workpieces exceeding 19mm are not suitable for laser welding.

• For materials with high reflectivity and high thermal conductivity, such as aluminum, copper and other alloys, the welding performance will be changed by the intensity of the laser.

• When performing medium to high energy laser automatic welding, a plasma controller is required to drive off the ionized gas around the molten pool to ensure the reappearance of the weld bead.

• Energy conversion efficiency is too low, usually below 10%.

• Rapid solidification of the weld bead may have porosity and embrittlement concerns.