Disk laser welding of Ti6Al4V alloy

In this study butt welding tests on 3 mm-thick Ti6Al4V sheets were performed using a 2-kW Yb:YAG disk laser. Titanium alloys are widely used in the aircraft industry, due to their high strength-to-weight ratio, corrosion resistance, operating temperature and bonding with composite materials (electrochemical compatibility, similar coefficients of thermal expansion). A full factorial experimental plan was conducted using three values of power and three welding speeds to obtain
good-quality butt joints. The joints were characterised in terms of the weld geometry, geometrical defects and porosity by X-ray examinations and the resistance by tensile tests. Vickers microhardness tests were performed from the base metal to the melted zone. The weld with the best geometric characteristics, least geometric defects and porosity content was selected for the tensile tests. Tensile tests have given satisfactory results because the selected specimen broke in the original gauge length, but away from the welds.