Effects of temperature gradient magnitude on bending angle in laser forming process of aluminium alloy sheets

Laser forming is a thermal forming process which uses laser beam irradiation to produce the desired final forms. In this article, the effect of temperature gradient across Al 6061-T6 aluminum sheets on bending angle is studied. Input parameters including laser power, scan velocity, beam diameter, and sheet thickness are the effective process parameters which influence the temperature gradient. Thus, a set of 81 numerical simulations based on a full factorial design with varying parameters is carried out and temperature gradient across the sheet thickness is measured. Effects of each input parameter on temperature gradient are determined using analysis of variance. Also, an equation is derived which predicts the temperature gradient for any arbitrary input parameter. The validity of the equation is done by comparing actual and predicted results. Numerical simulation is validated by experimental tests, which show a very close agreement. Finally, the effects of temperature gradient for three different sheet thicknesses on a final bending angle are derived. Results demonstrate that increase in temperature gradient across sheet thickness leads to increase in bending angle.