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Types of Laser Welding: from induction welding to keyhole

Types of welding - Industrial spot welding, automotive sector in Thailand

Depending on the intensity of the laser and the depth of the weld, some main types of laser welding can be distinguished:

  • induction welding or heat conduction,
  • transition welding,
  • deep or keyhole welding,
  • furthermore, laser welding can be continuous or spot welding.

Let's see in detail the description of these different types of laser welding.

Types of Laser Welding

Heat induction or heat conduction welding

Through this process the processed material is melted only on the surface and the depth of this type of welding usually does not exceed two millimeters.

The energy of the laser beam in conduction welding works at low power concentrations (0.5 MW / cm2) and penetrates the element thanks to the induction of heat, connecting the materials by solidified fusion, which in this case are mainly elements with very thin walls.

The end result is a clean, regular-looking weld joint that does not require further processing.

Laser welding types compared

Deep or keyhole welding

Unlike the previous type of laser welding, deep penetration welding applies the laser energy below the surface of the element to be machined.

The power concentration is very high (1.5 MW / cm2). This procedure is used to obtain a deep weld also allowing to weld different layers of different materials together.

This is an extremely fast and effective operation that melts the material in depth, generating a penetration hole also known as a keyhole with a size of approximately 1.5 times that of the laser beam.

The molten metal surrounds the hole solidifying in the back forming a kind of bead. It is therefore a technique used when it is necessary to obtain a weld with a high depth that can reach 25 millimeters in the case of steel.

Transition welding

A middle ground between heat conduction welding and keyhole welding is transition welding in which the power concentration is intermediate (1 MW / cm2) and the depth of the penetration is almost equal to its width.

The spot welder is welding the nut on the metal part

Continuous or spot welding

Depending on the welding joint that you want to create, the laser beam will be used in a different way so that laser welding can take place with continuous operation or thanks to the application of individual laser pulses.

In the case of continuous welding, the melting zone extends to the entire zone or profile to be welded and the metal solidifies after the laser beam has been applied in a continuous form.

In the case of spot welding, the laser beam is applied only during certain pulses of limited duration. The final result will be affected by the duration and frequency of the laser pulse and the metal melting spots may be partially overlapped.

For further information read -> Laser Welding of Steel and Metals: Advantages and operation

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