Understanding Wire Feeding in Laser Welding

Wire feeding technology in laser welding is a key component for achieving high-quality welding. By reasonably selecting wire material, diameter, wire feeding method and accurately controlling wire feeding speed, welding efficiency and joint quality can be effectively improved. The following details the working principle of the wire feeder, wire selection, wire feeding speed and other technical points.

1. Working principle of wire feeder

The wire feeder is a device specially used to deliver welding wire to the laser welding area. Its working process includes the following main links:

Wire feeding motor: The wire feeder drives the wire feeding system through the motor to push the welding wire into the welding gun.

Wire feed tube: The wire feeder feeds the welding wire into the welding gun through a slender delivery pipe. The wire feed tube is usually designed in a curved shape to ensure that the welding wire can be fed smoothly.

Wire nozzle: The welding wire delivered to the welding gun enters the welding area of the laser beam through the nozzle and acts on the welding part together with the laser beam.

The wire feeding system usually needs to work synchronously with the laser welding equipment to ensure the precise delivery of the welding wire and the effective irradiation of the laser beam, thereby ensuring the stability of the molten pool and the quality of the welded joint.

2. Selection of welding wire materials

The selection of welding wire material directly affects the welding quality and joint strength. Different base materials require different types of welding wire to ensure the performance of the welded joint. Common welding wire materials include stainless steel welding wire, aluminum alloy welding wire, copper welding wire, etc. The following factors need to be considered when selecting:

Base material matching: The chemical composition of the welding wire should match the base material to avoid welding defects due to material incompatibility.

Mechanical property requirements: The mechanical properties (such as strength, hardness, etc.) of the welding wire material should meet the application requirements to ensure that the joint has sufficient strength.

Corrosion resistance and high temperature resistance: For parts used in certain special environments, the corrosion resistance and high temperature resistance of the welding wire must also meet relevant standards.

3. Wire diameter selection

The size of the wire diameter directly affects the filler amount, molten pool control and welding speed of welding. The common wire diameter range is usually between 0.8mm and 2.4mm, and the specific selection depends on the following factors:

The thickness of the parent material: Thin plate welding usually uses a thinner wire (such as 0.8mm or 1.0mm) to accurately control the molten pool, while thick plates require a thicker wire (such as 1.6mm or 2.0mm) to provide sufficient filler material.

Welding position: For horizontal or hanging welding joints, thinner wires are easier to control the molten pool and reduce welding defects caused by excessive molten pools.

Welding power: A higher-power laser system can be matched with a thicker wire to provide more filler metal to meet high-strength welding requirements.

Choosing the right wire diameter helps improve welding efficiency, reduce welding defects, and ensure the quality of the welded joint.

4. How to feed the wire into the welding gun

The wire is usually fed into the welding gun through the wire feed tube of the wire feeder. The process of feeding the welding wire into the welding gun is very precise, and there are usually several ways:

Mechanical wire feeding system: The welding wire is driven into the wire feeding tube by the motor and drive wheel, and then the welding wire is fed into the laser welding area through the guide system.

Pneumatic wire feeding system: Gas (such as nitrogen or compressed air) is used to push the welding wire along the wire feeding tube. This method is relatively simple, but it requires precise airflow control to prevent the welding wire from deflecting or getting stuck.

The wire feeding process must ensure that the welding wire is smooth, unbroken, and does not interfere with other components. The design of the welding gun usually has a guide device to ensure the precise docking of the welding wire with the laser beam.

5. Wire feeding speed control

Wire feeding speed is one of the key parameters in laser welding. The selection of wire feeding speed needs to consider laser power, welding speed, wire diameter and the size of the molten pool. Usually, the wire feeding speed needs to be synchronized with the speed of laser welding to ensure that the welding wire can be fed into the molten pool at a steady rate.

Excessive wire feeding speed: may cause too much filler metal, increase the molten pool of the joint too large or overfilling, which may cause welding defects.

Too slow wire feeding speed: It may lead to insufficient welding wire, too small molten pool, insufficient strength of welding joint, and even incomplete welding.

In order to accurately control the wire feeding speed, modern wire feeders are generally equipped with high-precision control systems, which can automatically adjust the wire feeding speed according to real-time feedback of the welding process (such as laser power, welding speed, molten pool temperature, etc.) to ensure the stability and high quality of the welding process.

If you want to learn more about laser welding technology and wire feeding solutions, please contact Huawei Laser. Huawei Laser focuses on the research and development and application of laser welding technology, providing comprehensive technical support and customized services to help companies improve welding technology and production efficiency.