Experimental Study of Laser Cutting Process of Titanium Aluminium (Ti-Al) Based Composites Designed Through Combined Method of Powder Metallurgy and Thixoforming

摘要

Laser beam machining (LBM) is widely used as thermal energy based non-contact type advance machining process which can be applied for almost whole range of materials. It is suitable for geometrically complex profile cutting in the metals used in manufacturing engineering. In the present work, high-power laser cutting process of Titanium Aluminium (Ti-Al) based intermetallic composites designed through combined method of powder metallurgy and thixoforming were carried out. The thermal effects of laser cutting and effects of main operating parameters such as laser power, and cutting speed on the cutting edge and on the cutting surfaces were examined. The evolution of the microhardness underneath the cutting surface due to laser power is also examined. The composite used in this study was produced through combined method of powder metallurgical (P/M) and thixoforming. Microstructure of cutting edge and cutting surfaces are also investigated by scanning electron microscopy (SEM). Cutting surfaces have been analyzed with 3D optical surface roughness-meter (3D-SurfaScan). Roughness evaluations of the cutting surface depending on the cutting speed and cutting power were taken as optimization criteria that have been carried out by Taguchi method. A simple and useful tool was proposed for using in real manufacturing environment. Results exposed that good quality cuts can be produced in this Ti-Al based composite, at a window of laser cutting speed variable between 0.35 and 0.6 m/min and at a minimum heat input variable between 1400 and 2000 W.