Design and Optimization of the Local Laser Treatment to Improve the Formability of Age Hardenable Aluminium Alloys

Abstract

The research of innovative methodologies to improve the Aluminium alloys formability at room temperature still remains an open question: the local modification of the material properties via short-term heat treatments followed by the stamping at room temperature is reported to be an effective alternative to the forming in warm conditions. In the present work, such a methodology has been applied to the deep drawing of an age-hardenable Aluminium alloy (AA6082-T6) using an experimental/numerical approach. A preliminary extensive material characterization was aimed at investigating the material behaviour: (i) in the as-received condition (peak hardening), (ii) in the supersaturated condition (obtained by physical simulation) and (iii) after being locally solutioned via laser heating. A Finite Element based approach (Abaqus CAE, v. 6.17) was then used to design the laser treatment of the blanks to be subsequently deep drawn at room temperature: a 2D axisymmetric model of the deep drawing process was coupled with the optimization platform modeFRONTIER in order to define the radial extent of the laser heat treated area able to maximize the Limit Drawing Ratio. The experimental tests were finally conducted for validation purposes and revealed the effectiveness of the adopted approach which allowed to improve the drawability of more than 20% with respect to the as received condition (T6).

Investigation of the Tube Expansion Test with Elastomer Using Locally Overaged AA6063 Tubes

“…Literature confirms the effectiveness of the mentioned approach especially when applied to sheet metal parts [6,7], whereas only few examples deal with the possibility to apply a local modification to tubular components [8]. In a previous work, the authors investigated experimentally the effect of laser treatments on the formability of AA6063 tubular samples subjected to expansion tests with elastomer [9]: in particular, tubes in the T6 conditions were heated by means of a CO2 laser beam, along linear tracks parallel to the tube axis, to locally bring the material in the overaged state.…”

An Experimental and Numerical Study on Aluminum Alloy Tailor Heat Treated Blanks

“…Piccininni et al [24] proposed an optimization loop for the de termination of the parameters controlling the extension of the blank regions and the tem perature distribution. Additionally, to define the optimum radial extension submitted to local heat treatment in order to maximize the limiting drawing ratio, an optimization plat form was implemented [25].…”

Analysis of the Advantages of Laser Processing of Aerospace Materials Using Diffractive Optics

“…Subsequent studies were mainly devoted to improving the formability of ultra-fine-grained or hardened as well as multi-layered AlMgSi (6000 series) aluminum alloy by a specific heat treatment [78][79][80]. The authors of [81,82] state that compared with the traditional heat treatment process, for precipitation hardening of aluminum alloys, a great advantage of laser heat treatment is that the mechanical properties of materials in the treated area can be changed in a short time. Formability is improved by defining a specific local heat treatment layout with reference to the geometry of the blank.…”