Laser Spot Diameter
The laser focus diameter is the diameter of the focused laser beam on the powder bed surface. It determines energy density and minimizes thermal distortion, leading to better structural resolution.
Physical-chemical mechanism of action
The laser focus diameter refers to the diameter of the focused laser beam on the surface onto which powder is sprayed. A smaller focus diameter means a higher energy density per area, enabling more precise structural resolution in the material.
Metallurgical relevance & risks in welding
A too large focus diameter can lead to uneven energy distribution, resulting in thermal distortion and uneven stresses in the weld. This increases the risk of cracks and hardness issues. On the other hand, a too small focus diameter can lead to excessive pressure, which can damage the material or cause uncontrolled burning.
Workshop practice & instructions
To set the laser focus diameter optimally, the focus should be aligned on the powder bed surface. A typical focus diameter is about 0.2 to 0.5 mm, depending on the material used and the desired structural resolution. It is important to check the focus diameter regularly and adjust it to the specific conditions of the welding process.