Heat conduction welding
with an excellent welded seam

Diode lasers optimize heat conduction welding in several ways, with the uniform power output and homogeneous intensity distribution of the top-hat beam profile guaranteeing excellent seam qualities and high process stability.

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Diode lasers are used in various joining processes in industrial series production. High firmness and low distortion are the characteristics of laser welding involving our lasers. Plus, excellent seam surfaces can be achieved on the workpiece even at high cutting speeds. A distinction is made between heat conduction welding and keyhole welding.

Heat conduction welding with diode lasers is often used for workpieces with a low material thickness, such as thin sheets, foils, or wires. The laser beam is absorbed by the workpiece surface and the energy required is only led to the workpiece by heat conduction. The smooth, rounded welded seam that is created does not need to be post-processed. This method is suitable for the sheet metal working of materials such as stainless steel, for example, especially for manufacturing products that have to satisfy high requirements in terms of the visual quality of welded seams in the visible field.

The heat conduction welding process

Diode conduction welding is characterized by low exposure depths of a maximum of one millimeter and is mainly used for joining sheets with low material thickness. With heat conduction welding, the laser melts the sheets along the intended joint. The melted portions of the joint partners merge and then cool off to create the actual welding seam. This enables welded connections to be realized more quickly and with lower material distortion than with the usual welding methods. Furthermore, it generates smooth, pore-free welding seams that do not need any post-processing. This makes heat conduction welding the method of choice, especially in visible areas.

The process advantages of diode lasers

Laserline’s diode lasers optimize heat conduction welding in several ways, with their uniform power output and homogeneous intensity distribution (top-hat beam profile) guaranteeing excellent seam qualities and high process stability. Additionally, there are enormous economic advantages: with a lifetime of more than 30,000 operating hours, high efficiency, and low maintenance requirements, Laserline’s diode lasers are clearly superior to the other beam sources available.

Application examples


They can be found in every household and every factory canteen, and they always seem to be from a single cast: stainless steel sinks. However, they do have welding seams. The fact that you cannot see them often has to do with Laserline’s diode lasers: they enable heat conduction welding to be carried out, leaving no visible marks and offering a technically and economically optimum solution.

Metal bellows

Metal bellows are used when the thermal expansion of pipelines need to be compensated for, or vibrations between vacuum pumps and measuring instruments need to be decoupled. Welding thin and flexible membrane pairs requires an even heat input that creates stable, crack-free welding seams. Here, Laserline's diode lasers provide excellent results with heat conduction welding.