Laser bending of a Ti3Al-based intermetallic alloy

Ti3Al-based intermetallic alloy is known to have limited room-temperature ductility. In this paper, the deformation behaviour of a Ti3Al-based intermetallic alloy in laser bending was investigated for the first time. Experimental findings revealed that due to differential thermal expansion of the intermetallic alloy across the thickness, it could be deformed by a CO2 laser. The final bending angle was found to be strongly related to the laser power, the scanning velocity, and the number of irradiations. A linear relationship between laser bending angle and line energy was observed when the line energy lies between 1 and 5 J/mm. Significant changes in microstructures were observed in the alloy after bending, but no cracks or voids was found in the specimens. The hardness profile and the microstructures of the deformed specimen revealed that there was a steep temperature gradient across the thickness, and the laser bending mechanism is considered to be the temperature gradient mechanism. (C) 2001 Elsevier Science B.V. All rights reserved.