Adjustable ring shaping for laser welding applications

Abstract

High laser welding speed can be achieved by using a ring and central spot laser illumination profile, with an adjustable ratio of the ring energy to the spot enabling optimization of the process. We present a novel and simple diffractive‐based concept to achieve such adjustable shaping for standard fiber lasers. The module is rotation‐adjustable between 100 % energy in the central spot to no energy in the central spot, can work with both single‐mode and multimode lasers, is highly compact (less than 20 mm long) and has the high LDT of passive diffractive components. This concept obviates the need for special ring‐type fiber lasers, enabling simpler design of the welding laser head.

Welding of thin stainless-steel sheets using a QCW green laser source

“…Brodsky et al show that a preheating of the material, for example using a ring laser, allows an increase of the maximum speed by 55% without humping effect. It is also shown that the humping distance, i.e., the distance between two humps, increases with increasing line energy 17 .…”

Design of annular beam shaping system based on freeform surface

“…The application of annular flattened beam avoids the secondary mirror occlusion, and the far-field entry pupil power of annular flattened beam is higher [7].In the laser near-net shape forming technology, the annular flattened laser can produce better quality molten pool [8]. In high-speed laser welding, the welding speed is limited by physical phenomena such as spattering and humping [9]. The annular flattened beam can reduce the occurrence probability of these phenomena and improve the welding speed.…”