(Session 10B)Effect of Liquid Co_2 Cooling on Microstructural Evolutions of Friction Stir Welded Copper Joints

摘要

Electron backscattering diffraction was employed to investigate the grain refinement during the rapid cooling friction stir welding of copper. The results show that the ultrafined grains with a high dislocation density, which was detected at the back of the probe, mainly dependent on the grain subdivision. Liquid Co_2 cooling reduced the post-annealing effect and froze the ultrafined grains until the rotating tool completely passed through.