Selection of power density of fiber laser welding machine

Jul. 08, 2019

Selection of power density of fiber laser welding machine

With the continuous advancement of technology, the sheet metal industry has higher and higher requirements for the quality of welding strength and appearance, and the traditional welding method, due to the great heat input, will inevitably bring about distortion and deformation of the workpiece. The appearance of fiber laser welding machine compensates for the problem of workpiece deformation. It is a kind of high-energy laser beam coupled into the fiber. After short-distance transmission, it is collimated into collimated light by collimating mirror, and then focused on the surface of the workpiece. The heat is transferred to the surface of the workpiece. Internal diffusion, by controlling the parameters such as the width, energy, peak power and repetition frequency of the laser pulse, the workpiece is melted to form a specific molten pool, and whether the power density conversion rate can be controlled becomes the key to the technology.

 

With a higher power density, the surface layer can be heated to the boiling point within a few milliseconds of time, ie, vaporization occurs. Therefore, high power density is advantageous for material removal processing such as laser drilling, laser cutting, and the like. With lower power density, the surface temperature reaches the boiling point after several milliseconds and before the surface layer vaporizes, the bottom layer temperature reaches the melting point, which is easy to form a good fusion weld. In the actual welding process, the choice of power density depends on the characteristics of the material itself, and it needs to be determined according to the welding requirements. Laser welding machine in the case of a certain welding speed, the laser power should also be kept constant, not the bigger the better, the power just can penetrate the weld seam, too much will burn through, can not form a good weld.