Forging of Mg-alloys AZ31 and AZ80

Mg-wrought alloys recently became an engineer material of constantly increasing interest. The mechanical properties of extruded Mg-feedstock of the alloys AZ80 and AZ31 indicate their suitability for automotive applications in form of high-quality forgings. Therefore a detailed knowledge about the forming behaviour is of particular importance. In order to compare mechanical properties of available Mg-feedstock qualities compression tests at room temperature have been carried out by applying batches of AZ31- and AZ80-feedstock. Cylindrical specimens were made out of received continuously casted as well as extruded AZ31- and AZ80- rods. A quantitative analysis of Mg-feedstock's microstructure has been carried out. The characterization of the deformability of applied Mg-feedstock under hot working conditions could be performed by means of uniaxial plain strain upsetting tests at temperatures between 300 and 450 degrees C as well as logarithmic strain rates of 10(-1), 1 and 10s(-1). It is shown that the chosen parameter range ensures an enhanced deformability of continuously as well as extruded Mg-feedstock. The subsequently carried out determination of microstructural evolution could be related to obtained flow stress curves of applied batches of Mg-feedstock. Furthermore, FVM/FEM-systems have been employed in order to design a simplified geometry of heated forging dies suitable for forging tests. The tests have been carried out by means of a hydraulic press. During the tests their punch velocity has been varied between 1 and 40 mm/s. Hence numerically simulated results could be confirmed by practical tests. Exemplary forgings of a simplified shape were made out of all applied batches of Mg-feedstock. No remarkable failures have been detected.