Laser Beam Melting in Powder Bed
Powder bed fusion using a laser is a technology where a fine powder bed is built layer by layer by precise melting and solidification. It enables precise control over material distribution and the weld.
Physical-Chemical Mechanism of Action
A powder bed consists of a fine metal powder that is selectively melted by a laser beam. Melting occurs in short, controlled pulses, which raises the local temperature and solidifies the powder.
Metallurgical Relevance & Welding Risks
This technique allows high precision and uniform material distribution. However, inaccurate pulse management can lead to uneven melting, resulting in cracks or imbalances in the structure. Too high a powder content can also cause distortion and weld defects.
Workshop Practice & Instructions
To successfully perform powder bed-based laser welding, it is crucial to precisely control pulse duration and intensity as well as powder content. A typical pulse duration is between 10 and 20 microseconds with an intensity of 500 to 1000 W/cm². The powder bed should be fine and homogeneous to ensure even melting.