Laser welding technology as a contemporary new welding process, with the continuous development, improvement and innovation, has been widely used in aviation, aerospace, automotive, marine, hardware and other fields; with the rapid development of the automotive industry, the demand for welding of the body is also growing like crazy, currently used for automotive body-in-white welding methods mainly include resistance spot welding, MIG welding and MAG welding, as well as laser welding, along with the automotive industry has higher requirements for the production efficiency, production quality and aesthetics of cars. With the automobile industry's production efficiency, production quality and aesthetics have higher requirements, the outstanding advantages of laser welding has gradually become the mainstream of automobile body-in-white welding.
Laser brazing as a kind of laser welding, in the automotive industry applications mainly include: body roof, trunk lid, door drop gutter, side enclosure welding. Laser brazing as an advanced welding technology, compared with the traditional welding technology has a high energy density, welding speed, workpiece deformation is small, beautiful weld and other advantages are widely used in the field of automotive welding. Auto body laser brazing process is more mature, by changing the spacing of light wire, laser beam inclination, welding speed, wire feeding speed and other process parameters can significantly reduce the internal defects of the weld.
Laser brazing principle
Laser brazing uses laser as a heat source, the laser beam is focused and irradiated to the surface of the welding wire to make the welding wire melt, the melted welding wire uses liquid brazing material to wet the base material, fill the joint gap and diffuse with the base material, generating homogeneous solid melt and eutectic organization in the interfacial layer to form a good metallurgical bond with the workpiece, i.e., the connection between the workpieces is realized through the brazing layer, and the base material itself will not be seriously damaged by laser ablation, so the weld seam is shaped.That is, the connection between the workpieces is realized through the brazing layer, and the base material itself will not be seriously damaged by laser ablation, so the welded seam is beautifully shaped, uniform and consistent, and only requires simple or no treatment after welding.
Advantages of laser brazing:
- The brazing material melts, the base material does not melt, the shape of the workpiece after welding is more beautiful.
- Reduce the pure laser welding defects, such as porosity, cracks, product fit gap is too large, etc.
- Localized heating, not easy to produce heat damage, heat-affected zone is small, smooth and beautiful joints
- Compared with spot welding, it can reduce the melting of the galvanized layer, reducing the risk of corrosion.
- Laser heat source energy density, for the heat input can be controlled and adjusted, high welding efficiency, easy to realize automation.
- When the roof cover is connected to the side panels, the use of roof rubber sealing strip can be canceled, which is both beautiful and cost-saving.
Auto body-in-white laser brazing process
Automotive body-in-white brazing base material most of the 0.7mm galvanized sheet-based, in the automated production welding process, the gap between the two plates can only be controlled within 0.3mm, can not be completely controlled in the 0 gap, so in the welding test process needs to find the best process parameters compatible with the gap of 0 and 0.3mm; FIBO PAM point and ring energy tunable laser in the point of the power of 2300w, ring power 2000w, welding speed of 65mm, the laser can be used in the welding process. FIBO PAM point and ring energy adjustable laser in the point power 2300w, ring power 2000w, welding speed of 65mm / s, wire feeding speed of 5.1m / min welding process parameters, the two gaps weld are smooth and consistent, no biting edges, no welding, no porosity and other defects, brazing depth of 0.9mm, brazing width of 3.4mm or so, to meet the requirements of its welding.
Laser technology as an advanced processing technology, manufacturing applications in the automotive body-in-white, not only saves time and cost, but also improves the stability and reliability of the quality of the car, in the future automotive manufacturing, laser welding technology will be more widely used, and continue to innovate and expand the field of application, to promote the production of automobiles is more efficient, stable and reliable!
