External electric field effect on microstructure of friction welded joint of duralumin LY12

The width and the grain size in dynamic recrystallization zone (DRZ) of friction welded joint of duralumin LY12 under an external electric field have been studied quantitatively, and the mechanism of the electric field effect has also been discussed. The results show that the external electric field effect distinctly leads to decrease the microstructure distribution gradient along the axial direction and grain size, advance the equiaxial characteristics of grain and widen the equiaxial grain zone. In addition, the electric field effect results in increasing of the width of the DRZ from 10% to 30% under higher friction pressure. Under the middle friction pressure, the electric field effect not only results in obviously increasing the width of DRZ, but also changing the radial distribution rules of DRZ. The uniformity of microstructure and deformation, and refined grain of welded zone, resulting from the electric field effect, are favorable to the improvement of mechanical property of welded joints.