Keyhole Effect
Deep penetration effect: In laser or electron beam welding, a vapor-filled capillary channel is created by high-energy radiation, leading to extremely deep and narrow weld seams.
Physical-Chemical Mechanism of Action
High-energy radiation (laser or electron beams) heats the metal so intensely that it melts and evaporates within fractions of a second. This process forms a vapor-filled capillary channel between the pieces to be welded.
Metallurgical Relevance & Welding Risks
The deep-welding effect allows the creation of very narrow and deep welds, which is especially important in microelectronics manufacturing or in medical technology. However, insufficient evaporation can lead to porosity, which can affect the strength of the weld.
Workshop Practice & Action Guidelines
To make the most of the deep-welding effect, it's important that the metal is clean and free of dust. Beam power and duration must be set precisely to ensure even evaporation. For electron beam welding, the distance between the beam head and the workpiece surface should be adjusted to achieve optimal capillary channel formation.