Laser welding is a welding technique of joining metals or thermoplastics together using a laser beam. It is used in diverse industries, such as aerospace and fine jewelry. During this welding process, molten material from a weld pool is often emitted. This ejection is called a laser welding spatter that results in a weld with underfill, undercuts, craters, blowholes, or blowouts. That means- a damaged weld. We are going in-depth into this dangerous issue with this informative piece, learning about the causes and harms of laser welding spatter and also how to control it.
What Is Spatter in Laser Welding Process?
Weld spatter is tiny droplets of molten metal on the welding surface. During laser welding, the laser beam creates a welding pool on the surface. With fluctuating temperatures, a gasification process happens at the molecular levels of the molten alloys. These gases come out by splashing bubbles. These splashes spread droplets of molten material on the surface and cause spatters.
What Causes Laser Welding Spatter?
The causes of spatter in laser welding are incorporated by many factors, like material properties, weld design, welding parameters, and equipment conditions. Here are some common leading causes of spatter in laser welding.
Material Properties
The physical and chemical properties of the material may cause spatters. Some materials have a greater tendency to gasify at high temperatures. With more gas, the bubbles of molten material are bigger and expand with more jet power. These pop-ups create spatter on the surface.
Welding Parameters
The general parameters of welding are current, length of arc, angle, manipulation, and speed. Spetter is typically caused by the amperage and voltage settings used during welding. If the voltage is not ideal for a wire and gas combination, it fails to keep the wire and pool hot enough, causing a stubbing effect on the wire.
Weld Design
Weld design may also cause laser welding spatter. Factors such as weld shape, width, angle, etc., all affect the stability of the weld pool, which affects the generation of spatter.
Equipment Status
Conditions of the laser welding equipment can also affect the spatter. Problems such as the equipment’s unstable optical path, low-quality laser beams, and poor stability of the welding head may cause the welding pool to be unstable, resulting in a spatter.
What Are the Hazards of Laser Welding Spatter
In simple words, spatter ruins the quality of welding work. It decreases the durability of the piece. Some other potential hazards caused by spatter are discussed below.
Impaired Welding Quality
Spatter droplets develop poor finishing. As the material has spread out from the welding pool, this process creates holes or void spaces. These empty wholes weaken the surface and decrease the endurance of welding works.
Equipment Contamination And Failure
Molten metal caused by spatter is frequently deposited on the components of a laser welding machine. These plunk droplets affect the machine’s operation and may cause failure.
Human Health Risk
When a bubble of molten material splashes, it releases contaminated gases. Inhaling these gases can cause health problems, such as breathing issues. The high temperature of the battering material may cause severe burns on the skin and eyes of the welder.
Production Efficiency Decline
Welding works look less professional because of spatters. The welder either has to work on corrections or do the entire welding work again. Both of these processes consume extra working hours and decrease production efficiency.
Subsequent Processing Difficulties
After laser welding, the welded piece goes through processes like laser cleaning, coating, and other additional treatments without compromising the integrity of the weld. Spatters make these subsequent processes complex and difficult to perform.
Methods of Controlling Spatter in Laser Welding
There are several ways to suppress the generation of spatter that result in clean-cut welds with efficiencies. Adjusting the parameters of the laser equipment can effectively control the spatter problem during the laser welding process. Here, we discuss important considerations for controlling spatter effectively.
Optimal material selection
Not all metals are suitable for welding. Some low-grade alloys contain a lot of “filler” material to cut manufacturing costs. Ultimately, this affects the metal’s weldability. Choosing alloys with comparatively higher boiling temperatures and lower melting temperatures reduces the rate of gasification. Lower gasification reduces the jets of splashes and spatter.
The Reasonable Setting Of Welding Parameters
Set the parameters like current and laser power reasonably. Maintain a consistent speed with a correct focal length. That’ll help you avoid over-hitting the welding material. Overheating provokes spattering by forming more gas bubbles in the welding pool.
Optimized Weld Design
Optimize your weld design so that it is not too small or too big. If necessary, break down the bigger parts into small portions to reduce the duty cycle time. Avoid planning a too-wide welding arc because it means too much molten material, which may cause splashes to spread more droplets.
Equipment Maintenance And Calibration
Proper maintenance of machines and other equipment ensures a suitable laser beam quality. A stable welding head can help reduce spatter by reducing fluctuation in the weld pool.
Auxiliary Gas Control
Gases with low ionization energy ionize more frequently and form plasma in the presence of high-energy laser beams. This plasma helps maintain a stable arc during welding, improving control over heat input and reducing spatter. For instance, MDE gas (Methylaluminoxane/Diethylaluminum Chloride) is an auxiliary gas for aluminum-based alloys. It helps improve weld penetration and controls the risk of spatter.
Reduce Weld Pool Size
Wide and deep weld pools contain more molten metal particles, which increases gasification and bubbles. Bubbles splash molten material on the welding surface. Reducing weld pool size can significantly reduce this problem.
Welding Technology Training
Professional laser welding technology training helps operators understand the causes of spatter. They can avoid these reasons during work to control spatters, which will help improve their skills and welding capacity.
Conclusion
There is consistent growth in the use of microelectronics in several industries. That’s why laser welding is becoming more popular every day. Experience, expertise, and proper training can maximize these results effectively. Problems like spattering may look like obstacles in your welding work. But learning more about problems makes you an expert welder or a welding business owner.
However, for accurate and precise welding, the need for the best equipment is significant. With Fiber Laser Welder by your side, you can get your hands on top-graded fiber laser welding machines. Reach out now!
