Designing the laser heat treatment for the deep drawing of Al alloys by means of an optimization loop

Antonio Piccininni, Politecnico di Bari

CHALLENGE - Poor formability of light alloys limits the maximum achievable LDR, or limit drawing ratio, at room temperature. The LDR is the ratio between the punch diameter (D0 ) and the maximum drawable blank diameter without the occurrence of rupture. The Tailored Heat Treated Blank (THTB) is surely a promising technology to increase the achievable LDR. ​This work investigates the effectiveness of the THTB approach to optimize the localized heat treatment of the flange zone of an Al-Mg blank in hardened condition. The final aim is to improve the process performance (increase the LDR). ​

SOLUTION - Al-Mg alloys are extensively used for automotive applications, especially in body chassis components, thanks to the higher formability if compared to Al-Mg-Si grades.​ Mechanical behavior was investigated by means of a tensile test carried out on a 200kN electromechanical INSTRON 4485 universal testing machine, assisted by the DIC cameras. The coupling of the optimization platform modeFRONTIER and a 2D numerical model was created using the commercial FE code Abaqus. 

BENEFITS In the present work, both the extension of the laser heat treated region and the optimal initial conditions of the base material have been determined. The optimization process ran with genetic algorithm MOGA-II in modeFRONTIER. Results show a +24% increase in the Limit Drawing Ratio.