TY - JOUR

T1 - Grain size evolution simulation in aluminium alloys AA 6082 and AA 7020 during hot forward extrusion process

AU - Foydl, A.

AU - Segatori, A.

AU - Ben Khalifa, N.

AU - Donati, L.

AU - Brosius, A.

AU - Tomesani, L.

AU - Tekkaya, A. E.

PY - 2013/1

Y1 - 2013/1

N2 - The present paper investigates the grain size evolution in aluminium alloys AA 6082 and AA 7020 during hot forward extrusion process. The aim of the present work is the definition and implementation of a predictive algorithm that is able to compute the evolution of the grain shape during the process within the finite element method code Deform. Extrusion experiments were performed at two levels: at reduced scale for investigating and identifying the predictive equations and at industrial scale for validating the developed algorithm. At small scale extrusion, a complete factorial plan was performed for two alloys at three different temperatures, three extrusion ratios and two ram speeds: the discards and extrudates from the experiments were quenched immediately in order to avoid any potential recrystallisation, hence allowing measurements of transitional processing steps. At the industrial scale, instead, the 7020 alloy was extruded with two different die designs, thus producing a 20 mm diameter round bar under different extrusion ratios and strain paths. Finite element simulations were initially validated over visioplastic investigations in order to establish an accurate computation of the material flow, then experimental and numerical results were coupled, thus allowing the definition of the grain evolution model that was successfully integrated and validated on industrial scale trials.

AB - The present paper investigates the grain size evolution in aluminium alloys AA 6082 and AA 7020 during hot forward extrusion process. The aim of the present work is the definition and implementation of a predictive algorithm that is able to compute the evolution of the grain shape during the process within the finite element method code Deform. Extrusion experiments were performed at two levels: at reduced scale for investigating and identifying the predictive equations and at industrial scale for validating the developed algorithm. At small scale extrusion, a complete factorial plan was performed for two alloys at three different temperatures, three extrusion ratios and two ram speeds: the discards and extrudates from the experiments were quenched immediately in order to avoid any potential recrystallisation, hence allowing measurements of transitional processing steps. At the industrial scale, instead, the 7020 alloy was extruded with two different die designs, thus producing a 20 mm diameter round bar under different extrusion ratios and strain paths. Finite element simulations were initially validated over visioplastic investigations in order to establish an accurate computation of the material flow, then experimental and numerical results were coupled, thus allowing the definition of the grain evolution model that was successfully integrated and validated on industrial scale trials.

KW - Aluminium

KW - Extrusion

KW - Finite element method

KW - Microstructure

KW - Modelling

KW - Engineering

UR - http://www.scopus.com/inward/record.url?scp=84873865839&partnerID=8YFLogxK

U2 - 10.1179/1743284712Y.0000000132

DO - 10.1179/1743284712Y.0000000132

M3 - Journal articles

AN - SCOPUS:84873865839

VL - 29

SP - 100

EP - 110

JO - Materials Science and Technology

JF - Materials Science and Technology

SN - 0267-0836

IS - 1

ER -