Material preparation for laser welding (Part 2)
Posted by： Hangao Time：2024-6-13 16:44:33
Material preparation is the most critical first step in the laser welding process. The quality of the final weld is greatly affected by the cleanliness and correct alignment of the materials to be welded. It is very important to ensure that the material surface is free of contaminants such as dirt, oil, rust and oxide layers. Any residue on the surface can cause welding defects such as pores, cracks or lack of fusion. Therefore, careful material preparation is essential to achieve a strong and durable weld.
1. Material selection
The first sub-step in preparing materials is to select the appropriate material to be welded. Not all materials are suitable for laser welding. Common welding materials include various types of steel, aluminum and titanium. However, the choice of material depends on a variety of factors, such as application, cost and required welding performance. It is also important to consider the thermal conductivity, melting point and absorption characteristics of the material at the laser wavelength
2. Surface cleaning
Once the material has been selected, the surface to be welded must be carefully cleaned. The presence of contaminants such as dirt, oil, grease, oxide layers and any coatings can negatively affect the quality of the weld. Cleaning can be done using various methods, such as mechanical cleaning (sandblasting, wire brushing), chemical cleaning (solvents, acids) or thermal cleaning (flame cleaning, laser ablation). The method chosen depends on the material, the nature of the contaminants, and the desired weld quality.
3. Joint Design
Joint design is another important aspect of material preparation. The type of joint (butt joint, lap joint, T-joint, etc.), joint gap, and joint angle all affect weld quality. It is important to design the joint so that it allows the laser beam to properly penetrate and completely melt the material. Computer-aided design (CAD) software helps design joints and simulate the welding process to optimize joint design for laser welding.
4. Material Thickness
The thickness of the material is another important consideration. The laser power, welding speed, and focus position must be adjusted based on the material thickness to achieve the desired weld depth and width. Thicker materials may require higher laser power and slower welding speeds, while thinner materials may require lower power and faster speeds.
5. Preheating
In some cases, it may be beneficial to preheat the material before welding, especially for materials that are prone to cracking or deformation. Preheating helps reduce the temperature gradient across the material, thereby minimizing thermal stress and deformation. However, excessive preheating can lead to a decrease in the mechanical properties of the material, so it must be done and controlled carefully.
Guangdong Henkel Technology Co., Ltd.
Recommended reading: Laser welding production line
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