A Comprehensive Guide to Laser Welding Methods and Characteristics

1. Laser Fusion Welding

    

   Laser is a type of radiation with high energy density and intensity, capable of melting and heating materials within a tiny range. Thus, it enables efficient joining of virtually any material.

    
2. Laser-Arc Hybrid Welding

    

   The laser beam emitted by the laser generator forms a molten pool on the workpiece(s) to be welded via a wire feeding system. The arc is then used to melt the workpiece(s) or laminate the weldments together to complete the welding process.

    
3. Laser Brazing

    

   A dedicated laser generator and special nozzle or brazing head are used to heat the workpiece in the form of arc or optical radiation, thereby achieving welding.

    
4. Laser Melt Welding

    

   The laser generator emits a laser beam to heat the metal to a molten state, and then the molten metal is sprayed onto the workpiece through a nozzle to realize welding.

    

Characteristics of Laser Welding

1. Non-contact Surface Welding

    

   Welding is performed on the material surface without contacting the workpiece surface, making it suitable for any metal or alloy—especially materials that cannot be welded by traditional methods.

    
   During laser welding, the laser transfers energy to the material via a reflector, and the laser is reflected back to the generator. As the laser beam passes through the material to be welded, a molten pool is formed on the material surface. This allows laser welding to achieve high-precision joining, and even weld workpieces thicker than those compatible with traditional welding materials.
    
   Advantages: Capable of joining various materials (including composite materials).

    

   Disadvantages: Requires high-power laser generators and supporting dedicated welding equipment.

    
2. Adaptability to Complex Shapes

    

   Compared with argon arc welding, laser welding can handle parts with various complex shapes.

    
   For example, it can weld metals such as steel, copper and aluminum while ensuring high welding quality. It is applicable to welding smaller shapes on minor diameters, and can weld parts with a diameter of less than 1 mm but a weight of over 200 grams. In addition, thanks to the use of high-power laser generators, laser welding operations can be carried out without additional auxiliary equipment. Therefore, laser fusion welding is widely used in industrial production.
    
3. No Preheating Required (Generally)

    

   Preheating is not required in most cases (depending on process requirements; some materials may need preheating). The welding process involves no heat input, ensuring a stable molten pool. This unique welding method gains its advantages in scenarios where many traditional manufacturing processes are incompetent or costly. Since there is no heat input during welding, laser welding eliminates the need for preheating and cooling steps. It can ensure that the weld metal has optimal geometric shape, heat-affected zone and anisotropy. The welds feature excellent mechanical properties, making laser welding widely used in various industrial fields—especially in automotive manufacturing, machining and metalworking industries.

    
4. Simple Workpiece Pretreatment

    

   The workpiece surface requires no special treatment such as polishing or grinding. The operation is simple and convenient, as laser welding equipment can directly weld the workpiece.

    
   Application Scope: Welding of auto bodies, mechanical parts, molds, pipe fittings, etc. It is suitable for all metal materials, such as copper, aluminum, stainless steel and some special alloy steels, and can be widely applied in auto body manufacturing, industrial parts production and other fields.
    
5. Minimal or No Welding Wire Needed

    

   Welding can be performed with little or no welding wire, thereby reducing costs and time consumption. (In special cases, the use of welding wire depends on process requirements.)

    
   Therefore, in many cases, high-quality welding results can be achieved with a small amount of welding wire or low laser power.