Study on the impact of temperature on the warm bending of aluminium alloy sheets

Abstract

Warm forming of aluminum is a recent process and its developments have been mainly focused on drawing. This study takes a look at bending, a process widely used in industry. After the 2017A T4 and 6061 T6 aluminum alloys are characterized at both room and warm temperatures, bending of these materials is carried out at different temperatures. Various bending strategies are studied. The findings point to the value for these materials in heating the bend during the forming operation to avoid cracking, in some cases, and to minimize springback. An analysis of the sheet metal distortion mechanism is carried out based on micrographic sections sampled in the bend. The analysis highlights the formation of “macro-bands” indicating the location of the distortion. Asperities are observed on the outer surface. This could be the fracturing site of certain grains located in the grooves of the asperities, with possible intergranular or transgranular cracking. A potential follow-up to this study could be to assess the changes in the mechanical characteristics after the aluminum alloy sheets have cooled to room temperature.