Dissolution and precipitation behaviour for hot forming of 7021 and 7075 aluminium alloysThursday (09.11.2017) 14:40 - 15:00 Part of:
Due to their high strength, 7xxx aluminium alloys are used for structural components. With the objective of weight reduction, especially in the automotive industry, the interest in high strength aluminium components increases. One of the major challenges is the formability of these alloys during the production process, while retaining high strengths in service. A promising method is forming at elevated temperatures directly after solution annealing, the so called hot forming. However, this thermomechanical process requires a detailed comprehension of the dissolution and precipitation behavior during heating, solution annealing and subsequent combination of forming and cooling processes. Therefore, continuous heating dissolution and continuous cooling precipitation diagrams of the aluminium alloys EN AW-7021 and EN AW-7075 were determined in-situ by differential scanning calorimetry, supplemented by hardness tests. Suitable solution annealing conditions and critical cooling rates could be specified for each alloy.