Friction Stir Incremental Forming of A2017 Aluminum Sheets

Abstract

Formability of A2017-T3 aluminum alloy sheets by friction stir incremental forming was studied. A2017-T3 aluminum alloy sheets with a size of 100 mm x 100 mm x 0.5 mm were formed into frustum of pyramid shape having 40 mm x 40 mm right square bottom by a hemispherical tool with a diameter of 6 mm. Formability was evaluated by formable wall angle. When the tool rotation rate was 8000 - 10000 rpm and the tool feed rate was 3000 mm/min, the formability became maximum and the minimum wall angle was 25 o. The formed sheets were artificially aged and Vickers hardness test was performed to confirm the effect of temperature elevation during forming. The hardness of the formed sheets was increased due to the work hardening. As aging time increased, however, the hardness was decreased by over aging. The tensile strength of the formed sheet was the intermediate value between as received and over aged ones. The fracture elongations of the formed sheet after giving 69% logarithmic strain was a little less than as received one but greater than aged one.