Effect of scanning electron beam on solidified structure of welded Ti-6Al-4V alloy

In view of coarse columnar B grains in welded Ti alloy,the effect of scanning electron beam on solidified structure and microstruc-ture of welded Ti-6AL-4V ally was studied.It was indicated that fine e-quiaxed 13 grains had been gained by certain scanning electron beam.For example,when scanning frequency is 400 Hz,the β grains were about100 Ixm.And metastable β phase are fine and uniform.The related re-finement mechanism was discussed.