Microstructure characterization and texture evolution of Ti-6Al-4V cladding layer fabricated by alterative current assisted TIG

Abstract

In this paper, an alternating current (AC) was added to filling wire in the arc deposition process. The effect of alternative current on grains size and microstructure of Ti-6Al-4V cladding layers were studied. The microstructure evolution, grain size distribution, texture, and crystal twining of cladding layers with the addition of alternative current were studied in detail using metallographic microscopy (OM), electron back scattered diffraction (EBSD), and transmission electron microscope (TEM). The results reveal that the addition of AC can effectively inhibit β grain growth, the grains size decrease with the increase of AC value. The enhancement of microstructure uniformity and decrease of texture intensity have been realized by electromagnetic force produced by alternative current. Additionally, the {10-10}<10-12> compression twins system was observed in cladding layer at 45A. • A new method of alternative current assistedTIG welding (AC-TIG) was used to fabricate Ti-6Al-4V cladding layer. • The microstructure uniformity and texture intensity decrease will realize under the coupled magnetic-thermal field. • The {10-10}<10-12> compression twins was identified by TEM characterization in cladding layer when AC value is 45A.