HIGH SPEED VIDEO ANALYSIS OF MELT FLOW INSIDE FIBER LASER WELDING KEYHOLES

摘要

A high speed video survey of melt flow within fiberrnlaser welding keyholes has revealed a number ofrninteresting observations about the mechanics of weldrnformation. Using Streak Images and FFT (Fast FourierrnTransform) techniques to interpret the video results,rnquantitative values of fluid flow velocities down thernkeyhole front have been established. The results havernlead to a phenomenological understanding of some ofrnthe quality problems which arise at high weldingrnspeeds - such as undercut and humping.