Advantages of Hot Wire Laser Welding

September 12, 2024

Hot wire laser welding (also known as laser hot wire welding) is a welding method that combines laser welding and hot wire technology, in which a heated metal wire is used with the laser to improve the efficiency and quality of welding.

1. Working Principle

1.1 Cold Wire VS Hot Wire

Most laser wire welding uses cold wire. When the wire is not heated, a large part of the energy of the laser beam acts on the wire, which will undoubtedly reduce the welding speed. In order to make full use of the laser energy, the hot wire laser welding process can be introduced. Hot wire welding reduces the energy consumed by the laser on the wire and effectively increases the welding speed.

1. 2 Working Mechanism

The laser hot wire welding process requires an additional set of preheating equipment, which generally uses resistance heating. The electrode can be directly connected to the wire feeding roller, and the welding wire is instantly heated to a temperature close to the melting point through a large current. When the welding wire is sent to the edge of the welding pool, due to the high surface temperature of the welding wire, only a small amount of laser energy is required to melt it. The molten welding wire can absorb a large amount of laser energy and conduct it to the base material.

Compared with autogenous welding, hot wire laser welding is more conducive to the absorption of laser energy. Therefore, the welding speed of laser hot wire welding can be higher than that of autogenous welding. In order to avoid oxidation of the welding wire metal, the heated welding wire part is only 3~5mm away from the intersection of the laser beam and the welding wire, which can avoid excessive reduction in the temperature of the heated welding wire.

When using hot wire laser welding, there should be enough distance between the focusing lens and the workpiece to be welded for installing the heating device, and it is advisable to use a lens with a larger focal length. Although the focal spot diameter increases with the increase of focal length, which reduces the power density and is not conducive to energy absorption, increasing the focal length can increase the focal depth, which is more beneficial for thick plate welding.

2. Advantages of Hot Wire Laser Welding

2.1 Increased Welding Speed

Laser hot wire welding combines the fast focusing capability of the laser with the preheating effect of the hot wire, which significantly increases the welding speed, especially when welding thick materials.

2.2 Lower Heat Input

Since the laser beam can be concentrated in a small area, the heat-affected zone generated is small, which reduces the deformation and thermal stress of the material. This helps to maintain the physical properties and dimensional accuracy of the material.

2.3 Excellent Weld Quality

Hot wire laser welding can achieve a more uniform welding temperature distribution, improve the quality of the welded joint, and reduce the possibility of defects (such as pores, inclusions, cracks, etc.).

2.4 Diverse Material Welding Capabilities

This technology is capable of welding a variety of materials, including high-strength alloys, aluminum, magnesium, stainless steel, etc. This makes hot wire laser welding widely used in a variety of industries such as aerospace, automotive manufacturing, and electronic equipment.

2.5 Viable Welding Thickness

Hot wire laser welding is suitable for welding materials of different thicknesses, especially when welding thicker materials, which can effectively improve the penetration and quality of the welded joint.

2.6 Automation and Control

Laser welding technology is easily combined with automation equipment, which can achieve high-precision control and monitoring, further improve production efficiency, and reduce manual operation errors.

2.7 Reduced Post-processing Requirements

High-quality welded joints usually require less post-processing, such as grinding and deburring, which can save time and cost.

2.8 Low Energy Consumption

Compared with traditional welding methods, hot wire laser welding excels in energy efficiency and usually requires less energy, thereby reducing overall energy consumption.

2.9 Welding Visual Monitoring

Laser welding equipment is usually equipped with a visual monitoring system that can monitor the welding process in real time, which helps to detect welding problems in time and make adjustments.

Summary

Hot wire laser welding is an efficient, flexible and high-quality welding method that is increasingly used in modern manufacturing. Due to its many advantages, many industries are gradually adopting this technology to improve production efficiency and product quality.