Keyhole and Molten Pool Characteristics During the Laser Welding of a Ti-alloy
A-Q. Duan and L. Chen
In this paper the characteristics of keyhole and molten pool during laser welding of TC4, a Ti-alloy, have been studied through measuring its images. The study shows that the sizes of keyholes in all processes almost keep constant. This means that there is a quite steady absorption for laser energy in all welding processes of TC4, and this stability almost is not affected by welding
parameters. Because of this steady energy input, the steady molten pool would be formed in all quasi-stationary processes, and it is verified by images of molten pool at different time. The results at different heat input clearly show that the area of different temperature rises with the increase of the heat input. The length of molten pool also increases with the heat input. But the heat input has less influence on the width than others.
Keywords: Laser welding, keyhole, molten pool, Ti-alloy