Thermo-mechanical forming of Al-Mg-Si Sheet

In warm forming of aluminum sheet, the temperature and strain rates vary considerably. In simulations, the material\ud model must be capable to predict stresses within this wide range. Here, the physically based Nes model is used to describe\ud the behavior of AA6061-T4 sheet material under warm forming conditions. A significant change of earing behavior is\ud found between room temperature and 250 ºC. Crystal plasticity calculations showed a reasonable correspondence of\ud changing r-values if extra slip systems are considered at high temperatures. Satisfactory results are obtained for simulation\ud of tensile tests and cylindrical deep drawing

Mechanical and forming properties of AA6xxx sheet from room to warm temperatures

The influence of temperature on the mechanical behaviour of the heat treatable Aluminium alloy EN AW-6061 has been investigated with a series of tensile tests. It is found that temperature has an effect on both the storage of dislocations and dynamic recovery. The results have been used to fit the dislocation based Nes work-hardening model. Simulations show that the model captures properly the dependence of yield stress and work-hardening rate with temperature and temper. The work-hardening model has been implemented into the Dieka FEM to simulate the warm deep drawing of cylindrical cups. Comparison of the simulated and experimental punch force and cup thickness reveals a good correspondence and validates the proposed modelling approach

Thermo-mechanical forming of Al-Mg-Si Sheet

In warm forming of aluminum sheet, the temperature and strain rates vary considerably. In simulations, the material model must be capable to predict stresses within this wide range. Here, the physically based Nes model is used to describe the behavior of AA6061-T4 sheet material under warm forming conditions. A significant change of earing behavior is found between room temperature and 250 ºC. Crystal plasticity calculations showed a reasonable correspondence of changing r-values if extra slip systems are considered at high temperatures. Satisfactory results are obtained for simulation of tensile tests and cylindrical deep drawing