电子束扫描对Ti-6Al-4V合金焊缝金属组织的影响

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

摘要: 针对钛合金焊缝金属易形成粗大柱状晶严重影响其性能的特点,利用电子束扫描焊接,对Ti 6Al 4V合金焊缝金属凝固组织及微观组织进行了研究。结果表明,当电子束扫描频率为0~200Hz时,焊缝凝固组织均为300μm以上粗大柱状晶;当电子束扫描频率为300~1000Hz时,焊缝凝固组织细化为100~300μm等轴晶。其中扫描频率为400Hz时,焊缝金属凝固组织得到最佳细化效果,晶粒尺寸为100μm,同时焊缝金属微观组织均匀细小。并分析了有关细化机理。

Abstract: 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.