High-energy beams
High-energy beam welding: electron beam and laser

The specific power developed by high-energy beams gives rise, on impact with matter, to a characteristic penetration phenomenon due to the formation of what is generally known as a capillary or keyhole.

We simply explain its formation as follows.

The power of the beam develops almost entirely at the point of impact on a target, giving rise to instantaneous sublimation of the material. In the case of a metallic material, this generates a high vapor pressure, pushing a film of molten metal towards the edges and creating a small cavity in the surface, which the beam uses to advance. From close to close, a narrow shaft is formed, which propagates through the material. This well, which is only slightly larger in diameter than the beam, is physically occupied by a plasma...