Three Major Defects in Laser Welding and Their Solutions
Laser welding is an efficient and accurate welding method that has been widely used in modern industrial manufacturing. However, any welding process inevitably encounters some defects, and laser welding is no exception. Therefore, this article aims to explore the common types of defects in laser welding, analyze their causes, and propose corresponding solutions.
1. Laser Welding Spatter
What it looks like
These spatters typically appear as small metal particles adhering to the weld pool and the surface of the workpiece, causing variations in surface roughness and possibly scratching the base material.
What it can cause
The harm of spatter lies in their potential to damage the surface of the workpiece and contaminate optical media. Additionally, spatter may adhere to optical media such as lenses, isolators, and filters, leading to performance degradation of these components, necessitating rework or replacement.
What causes it
1.Contamination of the material surface.
2.Geometry of the weld seam.
3.Unreasonable parameter settings.
How to fix
1.Clean the material or workpiece surface to remove oil stains and contaminants.
2.Adjust the laser power and welding speed appropriately.
3.Optimize the geometry of the welded workpiece and assembly accuracy.
2、Laser Welding Undercut
What it looks like
Laser welding undercut is mainly manifested as grooves melted by the arc on the edge of the base material along the weld seam. These grooves often result in localized depressions in the metal on both sides of the weld, leading to irregular incomplete fusion within the weld.
What it can cause
1.Reduced strength of the formed weld seam in laser welding.
2.Cracking is prone to occur at the undercut, resulting in complete failure of the welded workpiece.
3.Affects the fatigue strength and corrosion resistance of the welded workpiece.
What causes it
1.Uneven focusing of the laser beam.
2.Unreasonable design of weld seam geometry.
3.Welding speed too fast or too slow.
4.Presence of oxide on the material surface.
How to fix
1.Optimize welding process parameters.
2.Reasonably design weld seam geometry.
3.Perform polishing, cleaning, and repair treatments.
4.Ensure cleanliness of the material surface.
3、Laser Welding Deformation
What it looks like
Laser welding deformation is typically characterized by changes in the shape, size, or position of the welded joint, deviating from the expected design or requirements. This deformation may manifest in various forms, including but not limited to bending, twisting, shrinking, or expanding.
What it can cause
1.Decreased strength, sealing, and fatigue life of the welded joint.
2.Difficulty in assembly, increasing the cost of subsequent processing or repair.
3.Product scrapping, resulting in economic losses.
What causes it
1.Improper selection of welding process parameters.
2.Influence of welding materials.
3.Effects of thermal stress and shrinkage force.
How to fix
1.Optimize laser power, welding speed, focal length, and other parameters.
2.Select suitable welding materials and processes.
3.Use fixtures or support structures.
4.Utilize methods such as heat treatment and mechanical correction for repair.
Advantages and Disadvantages of Laser Welding
Laser welding is a highly precise welding method with many advantages and some limitations:
Advantages of laser welding:
1.High precision: The laser beam can precisely control the welding position and depth, making it suitable for welding small, complex components.
2.Wide applicability: Laser welding can be used to join a variety of materials, including metals, non-metals, and composite materials, with extensive application prospects.
3.Low heat input: Compared to traditional welding methods, laser welding has lower heat input, reducing deformation and the heat-affected zone.
4.Environmental friendliness and energy saving: Laser welding does not require electrodes and welding wires, reducing welding pollution. Moreover, laser beam energy utilization is high, resulting in significant energy savings.
Disadvantages of laser welding:
1.Welding thickness limitation: Laser welding may encounter difficulties when welding thicker materials, requiring techniques such as multi-layer welding or multi-pass welding, which increase welding complexity and cost.
2.High initial cost: Laser welding equipment is expensive, requiring a significant initial investment, making it unsuitable for small-scale production or individual users.
Conclusion
In practical applications, it is necessary to optimize and adjust welding processes and parameters according to specific situations to ensure welding quality and stability. At the same time, strengthening monitoring and detection during the welding process, timely discovering and dealing with potential defects, is also an important measure to ensure the quality of laser welding.
