EBSD analysis of microstructure and texture of Ti₃Al alloy laser welded joints

The technique of electron backscatter diffraction(EBSD) was used to investigate the microstructure,grain size,grain shape,and texture of Ti-23Al-17Nb(at.%) alloy laser welded joints,which include weld,heat-affected zone(HAZ) and base material.The results indicated that the microstructure of the weld and HAZ consisted of B2 phase.The base material consisted primarily of B2 and a small quantity of α₂ phase.The grain size became gradually larger from the base material to HAZ and weld.The base material was composed of fine equiaxial grains,and the grain size of B2 phase was larger than that of α₂ phase.The B2 phase in the weld had the highest density of(001) texture component while it in base material and HAZ was dominated by(001) texture component.The α₂ phase in the base material was dominated by(1 0-1 0)-1 2-1 10texture component.The HAZ had a high density of low angle boundaries.There were certain relations between the texture of weld and the texture of HAZ and base material.