Prediction of the tensile strength of aluminium alloy 5052-H32 fibre laser weldments using regression analysis

Abstract

Aluminium alloy 5xxx series are increasingly replacing steels in marine, automotive and aerospace industries for making structural parts because of their high strength, low density and high corrosion resistance. In this work, analysis of the weld quality of AA 5052-H32 fibre laser weldment within a process window (laser power 2400–2600 W; welding speed 0.03–0.08 m/s; focal position − 3.75 to − 4.25 mm) as well as development of a regression model predicting the weld quality was carried out. A novel approach for analysing and predicting the tensile strength (TS) of the weldment using statistical analytical technique was developed. Single and interaction effects of the parameters on the TS were analysed. A regression mathematical model with a predicting accuracy of 91% for the TS of fibre laser welded AA 5052-H32 was developed. The model revealed that the focal position, welding speed and welding speed–focal position interaction contributed significantly to the TS of the weldments. The TS is more sensitive to the welding speed at low focal position (between − 4.0 and − 4.25 mm). Maximum TS (~ 177 MPa) was found at laser power of 2400 kW, welding speed of 0.03 m/s and focal position of − 3.75 mm. The measured and predicted maximum TS obtained for the fibre laser welding process is close to that of the as-received AA 5052-H32 (~ 228 MPa). The model has found applications in a metal sheet company for quick determination of appropriate fibre laser welding parameters that give high-quality joining of thin sheet AA 5052-H32.