Use of internal variable models to predict the high temperature behaviour of a 6xxx industrial alloy

In this study, we have used the internal variables models in the case of an industrial 6063 alloy. The alloy has been studied in two different conditions (T5 and overaged) and at three different temperatures: 175°C, 250°C and 300°C. The microstructure of the alloy has been thoroughly studied and especially the precipitation state. Then the mechanical behaviour at high temperature has been characterised using different types of tests (creep tests, strain-rate jumps tests and tensile tests at constant strain-rate). With this method, it is possible to study the high temperature steady state behaviour over a wide range of strain-rates. We were also able to describe the transient behaviours and to predict creep curves from tensile tests data with no adjustable parameters.