What Materials Can be Welded by Laser Welding Machine and Matters Needing Attention

The most advanced welding technology in the world today is laser welding. The laser welding machine uses high-energy laser pulses to locally heat the material in a small area. The energy of the laser radiation diffuses into the interior of the material through heat conduction, and the material is melted to form a specific molten pool. It is a new type of welding method, mainly for the welding of thin-walled materials and precision parts, and can realize spot welding, stitch welding, sealing welding, etc., with high aspect ratio, small weld width, small heat affected zone and fast welding speed. , beautiful, no need or simple treatment after welding, small focusing spot, high positioning accuracy, easy to achieve automation. The traditional welding machine technology uses the characteristics of high temperature during welding, and then the welding effect is not good due to the poor temperature and time control. However, since the laser welding machine was launched, its welding effect has been loved by everyone, and More and more companies use laser welding machines for processing and manufacturing. What materials can laser welding machine weld?

1. Die steel

Laser welding machine can be applied to S136, SKD-11, NAK80, 8407, 718, 738, H13, P20, W302, 2344 and other types of die steel welding, and the welding effect is good.

2. Carbon steel

Carbon steel is welded by laser welding machine, and the effect is good. The quality of welding depends on the content of impurities. In order to obtain good weld quality, preheating is required for carbon content above 0.25%. When steels with different carbon content are welded to each other, the welding torch can be slightly biased to the side of the low carbon material to ensure the quality of the joint. Because the heating speed and cooling speed of the laser welding machine are very fast, so when welding carbon steel. Weld crack and notch susceptibility also increases with increasing carbon content. Both medium and high carbon steels and common alloy steels can be laser welded well, but preheating and post-weld treatment are required to relieve stress and avoid cracks.

3. Alloy steel

Laser welding of low-alloy high-strength steels, as long as the selected welding parameters are appropriate, can obtain joints with mechanical properties equivalent to those of the base metal.

4. Stainless steel

In general, stainless steel welding is easier to obtain high-quality joints than conventional welding. Due to the high welding speed and small heat-affected zone of laser welding, the overheating phenomenon and the adverse effect of the large linear expansion coefficient during welding of stainless steel are alleviated, and the welding seam has no defects such as pores and inclusions. Compared with carbon steel, stainless steel is easier to obtain deep penetration narrow welds due to its low thermal conductivity, high energy absorption rate and melting efficiency. Welding thin plates with low-power laser welding can obtain joints with good appearance and smooth and beautiful welds.

5. Copper and copper alloys

Soldering copper and copper alloys is prone to problems of lack of fusion and penetration, so a heat source with concentrated energy and high power should be used and preheating measures should be used; when the thickness of the workpiece is thin or the structural rigidity is small, and there is no measure to prevent deformation, welding It is easy to produce large deformation after welding, and when the welded joint is constrained by a large rigidity, it is easy to produce welding stress; when welding copper and copper alloys, it is easy to produce hot cracks; porosity is a common defect when welding copper and copper alloys.

6. Aluminum and aluminum alloys

Aluminum and aluminum alloys are highly reflective materials. When aluminum and its alloys are welded, the solubility of hydrogen in aluminum increases sharply with the increase of temperature. The dissolved hydrogen becomes the source of defects in the weld, and there are many pores in the weld. , and the root may appear void during deep penetration welding, and the weld bead formation is poor.

The properties of the metal material determine the welding process. The following points are analyzed for the attention of metal laser welding:

1. The cooling rate of metal materials is fast, which is determined by the carbon content in the metal, which affects the embrittlement, micro-cracks and fatigue strength of metal materials.

2. During the welding process, the highly volatile alloying elements in the metal alloy are volatilized from the molten pool, which will lead to the generation of pores and may also cause undercuts.

3. When welding carbon steel materials, the carbon content of the material should be less than 2%. When the carbon content is higher than 3%, the difficulty of laser welding will increase, the tendency of cold cracking will increase, and the fatigue and bottom of the material will increase. The brittle fracture tendency under the grain condition, and a certain amount of shrinkage of the weld is considered in the joint design, which is beneficial to reduce the residual stress and crack tendency of the weld and the heat-affected zone.

4. When the carbon content of the laser welding machine is higher than 3% and the carbon content is less than 3%, the form of paranoid weld can be used to limit the transformation of martensite, eliminate stress, and reduce the generation of cracks. This reduces both the quench rate and the tendency to crack.

5. Whether it is pulsed laser welding or continuous laser welding, the general pulsed laser welding machine can reduce the heat input, and can also reduce the generation of thermal cracks and the deformation of the workpiece.