What materials can be welded by laser welding?

During the laser welding process, high-energy laser pulses are used to locally heat the material. Through heat conduction, the laser radiation energy diffuses into the material, melting it to form a specific molten pool, thus achieving welding.

Laser welding machine, also called laser welding machine, laser welding machine, is a laser material processing equipment. According to its working mode, it can be divided into laser welding machine, automatic laser welding machine, laser spot welding machine, and fiber-optic transmission laser welding machine.

Weldable materials:

Mold steel:

Such as S136,SKD-11,NAK808,407,718,738,H13,P20,3,022,3444 have good welding effect.

Carbon steel:

Carbon steel adopts laser welding, and the welding effect is good. The welding quality depends on the impurity content. In the case of carbon content greater than 0.25%, in order to obtain good welding quality. When welding steels with different carbon contents, the welding torch can be biased towards the low-carbon material to ensure the quality of the joint. Because the heating and cooling speeds are very fast during laser welding, when welding carbon steel, the higher the carbon content, the higher the sensitivity to welding cracks and notches. Medium-high carbon steel and ordinary alloy steel can be laser welded well, but stress should be eliminated to avoid cracking.

Stainless steel:

Compared with conventional welding, it is easier to obtain high-quality joints in stainless steel welding. Because the welding speed and heat-affected zone of laser welding are very small, the adverse effects of overheating and large linear expansion coefficient on stainless steel welding during welding are reduced, and there are no defects such as pores and inclusions. Compared with carbon steel, stainless steel has lower thermal conductivity, higher energy absorption rate and higher melting efficiency, and it is easier to obtain deep-melting narrow welds. Low-power laser welding of plates can produce joints with good appearance, smooth welds and beautiful appearance.

Copper alloy steel:

When copper materials are welded, problems such as lack of fusion and lack of penetration are prone to occur. A heat source with concentrated energy and high power should be used in conjunction with preheating measures. When the workpiece is thin or the structural rigidity is small, if no measures are taken to prevent deformation, large deformation is likely to occur after welding. When the welded joint is constrained by greater rigidity, welding stress is likely to occur. When welding copper and copper alloys, thermal cracks are also likely to occur. Porosity is a common defect in copper alloy welding.

Plastics:

Currently, almost all thermoplastics and thermoplastic elastomers use laser welding technology. Common welding materials include PP, PS, PC, ABS, polyamide, PMMA, polyoxymethylene, PET, PBT, etc. Other engineering plastics, such as PPS and liquid crystal polymers, cannot be directly laser welded due to the low transmittance of the laser. Usually, carbon black is added to the base material so that the material can absorb enough energy to meet the needs of laser welding.

Aluminum alloy laser welding:

The main difficulty in laser welding aluminum and aluminum is that it has a high reflectivity to the Co2 laser beam with a wavelength of 10.8pon. Aluminum is a good conductor of heat and electricity, and its high density of free electrons makes it a good light reflector, with an initial surface reflectivity of more than 90%. That is, deep penetration welding must start from 1000% of the input energy, which requires high input power to ensure the power density required at the beginning of welding and form a small hole.

Laser welding of magnesium alloys:

The alloy density is 36% lower than that of Al. It is a high-strength alloy and has received widespread attention. For this purpose, pulsed YAG and continuous C02 laser welding experiments were conducted. AZ31B-H244 alloy plate thickness 1.8MM (3.27%Al, 0.79%Zn), the best welding conditions with less defects are average power 0.8kW, 5ms, 120Hz, 300mm/s, focus size 0.42mm, continuous C02 laser welding good penetration.

High strength low alloy steel:

Using laser welding of low alloy high strength steel, as long as the appropriate welding parameters are selected, the joint with the same mechanical properties as the parent material can be obtained. HY-130 steel is a typical low alloy high strength steel. After quenching and tempering, it has high strength and good crack resistance. When welding with traditional welding methods, the weld and HAZ structures present coarse grains, fine grains and rod-shaped structures of the original structure. Compared with the parent material, the toughness and anti-interference ability of the joint are greatly reduced, and the weld and HAZ metal structures are particularly sensitive to cold cracks.

Summary:

The welding of materials with laser welding function is far more than these. Laser welding can be performed between a variety of dissimilar metals. Laser welding technology can be applied to a variety of dissimilar metals, such as copper-nickel, nickel-titanium, copper-titanium, titanium-molybdenum, brass-copper and low-carbon steel copper.