Study on Crack Generation of Ti-Al Alloy Deposited by Plasma Arc Welding Arc.

Ti-Al(48at.%) alloy was deposited by twin-wire plasma arc welding additive. The preheating temperature was 560, 620 and 680 °C, respectively. The results show that when the preheating temperature was 560 and 620 °C respectively, cracks appeared at the arc-starting part of the lower of the sample. The preheating temperature was 680 °C, and the sample had no cracks. The numerical simulation results show that the transient stress decreased with the increased of the preheating temperature. The transient stress at the lower of the specimen was greater than that at the middle and top, and the YZ shear stress and Z-direction stress at the front end were greater than those at the middle and end, resulted in cracks at the arcing starting part of the lower. [ABSTRACT FROM AUTHOR]