Thermo-Mechanical Modelling of Heat Treated Aluminium Cast Parts

Casting and heat treatment of aluminium parts are important to the automobile industry. To improve the design and manufacturing of these components, it is important to do a proper analysis of the thermal and mechanical properties and conditions. Furthermore, it is possible to use the results as initial conditions for a subsequent structural analysis and by that model the full load history of the material. The manufacturing stages can have high influence on deformation and development of residual stresses.

This paper presents a study on the modelling of the thermo-mechanical conditions in the cast and heat treated material, using a unified approach to describe the constitutive behaviour. At high temperatures, creep is pronounced and the model includes a type of Norton's power law, to integrate the significant contribution of creep to the inelastic strains. At lower temperature levels, the influence of time effects decrease and the formulation reduces to a time independent formulation, like classical J2-flow theory. Several tensile and creep experiments have been made at different temperature levels, to provide input data to the material model. The numerical model is applied on different industrial examples, to verify the agreement between measured and calculated deformations.