Fine microstructure characteristic in fusion zone of electron beam welding of Ti-6Al-4V

Microstructure characteristic in fusion zone of electron beam welding of Ti-6Al-4V was studied by means of OM, XRD, EP-MA and TEM. The results indicated that crystallizing morphology of fusion zone was evolved into columnar crystals from equiaxed grain in base metal. Only α′ phase presenting basket-weave microstructure was produced. Lath of fine microstructure in fusion zone present multi-directional distribution. Some β stabilized element such as Fe, V concentration distribution fluctuation occurred nearby fusion line. Dislocation density in fusion zone obviously decreased than that of base metal.