Time Dependent Deformation of the Magnesium alloys AS21 and AZ91 around 100 deg. C

摘要

The deformation behaviour of the pressure die cast Mg al- loys AZ91 and AS21 was investigated in uniaxial compres- sion and tension at constant stress σ as well as in compres- sion at constant strain rate ε in the temperature range 70 deg. C躎≤135 deg. C, which is of interest for the use of Mg alloys in automobiles. At ε = 10~3 s~-1, the yield stress Is only weakly dependent on T, whereas the maximum de- Formation resistance is strongly influenced by T. Normali- Zation with the diffusion coefficient D and the shear mod- Ulus G of pure Mg produces and essentially unique relation- Ship between normalized ε and normalized σ for the maxi- Mum deformation resistance.