Laser Welding Explained | Advantages and Disadvantages
Many of the amazing creations made possible by technology appear as if you took them directly from a movie. For instance, laser welding is feasible and presently in use, while laser cutting has been around for a while. For many welders, this "high-tech" style of welding is new or unfamiliar. This article discusses the advantages and disadvantages of laser welding technology.
What Is Laser Welding?
A laser beam creates a weld to fuse metals or thermoplastics during laser welding. Laser welding can generate narrow, deep welds between square-edged pieces in thicker materials and fast welding speeds of meters per minute in thin materials due to the concentrated heat source.
Conduction limited welding and keyhole welding are fundamentally different ways laser welding works. The interaction between the laser beam and the welded material depends on the laser's power density when it hits the workpiece.
Conduction Limited Welding – Conduction-limited welding occurs when the power density is less than 105W/cm2. The laser beam does not penetrate the material; it is absorbed into its surface. Because of this, conduction-constrained welds frequently have a large width-to-depth ratio.
Keyhole Welding – Laser welding is more frequently carried out by adopting a keyhole mechanism and larger power densities. The material in the path of the laser beam melts and vaporizes when the laser beam is focused on a small enough area to provide a power density typically> 106-107 W/cm2 before substantial amounts of heat can be dissipated by conduction. The concentrated laser beam enters the workpiece and creates a "keyhole" cavity filled with metal vapor (which, in some cases, can even be ionized, forming a plasma).
The Process Of Laser Welding
A strong laser beam is used in laser welding to heat the joint. When the material resolidifies, the components are fused because it has melted on both sides of the junction. The bare minimum requirements are a laser, lenses to focus where you want, a mechanism to precisely move the beam over the joint, and a worktable to fit up and hold the components.
Using optics to "organize" or "refine" light waves into a focused, highly intense beam is rather difficult. Therefore, a laser's workings are outside this page's purview. There are numerous types of lasers with various powers. But the proper beam can rapidly raise the temperature of the metal on both sides of a joint.
The laser quickly applies the needed energy. You might need to fire the beam at the metal in pulses that last only a few milliseconds, depending on your laser and the nature of your workpieces. Or perhaps a continuous beam is ideal. You have a decent degree of flexibility over how the LBW system transfers heat to the pieces, but it depends on how much power is required.
Naturally, the molten metal will take a few seconds to cool and resolve. However, overall, the welding process is quick, making it a very efficient means of combining parts. Because of this, LBW is popular in applications requiring high welding speeds, such as manufacturing lines.
What Is The Purpose Of Laser Welding?
Many locations that use laser welding strongly emphasize creating neat, attractive welds. These consist of the following.
- Automobile production.
- Making jewelry.
- Fluid and hydraulic control components.
- Narrow shell assemblies that are distorted.
- Fuel rails.
- Medical equipment
- Heat exchangers are made of stainless steel.
- Thin-gauge metal tubes, components, and boxes
Benefits of Laser Welding
When compared to other welding methods, laser welding provides the following benefits:
- It enables quick welding, deep welding, and small deformation.
- The welding apparatus is straightforward and can be used to weld at ambient temperature or under various circumstances. For instance, a laser beam does not change as it passes through an electromagnetic field. Also, laser welding can be done in the air, vacuum, and with certain gases. Even materials like glass that are transparent to the beam can be welded through.
- It successfully joins dissimilar materials and can weld refractory materials like titanium and quartz.
- In high-power systems, a depth-to-width ratio of up to 5:1 and even up to 10:1 is possible due to the high power density made possible by laser beam focusing.
- Laser welding may perform micro-welding by obtaining a tiny, precisely positioned spot. It is suitable for joining tiny and micron-sized components made in bulk. (The smallest spot allowed is 0.1mm)
- Laser welding is flexible since it can reach hard-to-reach areas and uses non-contact long-distance welding. Laser welding has become increasingly popular and practical for automatic integration due to the YAG laser processing industry's recent use of optical fiber transmission technology.
- The laser beam may quickly and easily achieve beam splitting according to time and location, allowing for multi-beam simultaneous and multi-station processing and creating the ideal environment for more precise welding.
Drawbacks of Laser Welding
However, there are certain drawbacks to laser welding as well:
- The weldment demands very high assembly accuracy, and the beam position on the workpiece shouldn't deviate too much. This is so that welding faults can occur when the workpiece assembly or beam location is imperfect. This is because the spot size after laser focusing is tiny, and the weld is narrow.
- The laser and its associated technologies are expensive and require a sizable upfront investment.
Leave a comment