Tensile and Compressive Creep Behavior of Magnesium Die Casting Alloys Containing Aluminum

Summary

The automotive industry has renewed interest in magnesium alloys for improving fuel efficiency through vehicle mass reduction. One limitation of magnesium alloys that has hindered more widespread application is their poor creep resistance. This study was conducted to expand the knowledge of creep mechanisms in the current commercial and experimental die casting alloys, with a view towards developing new alloys with improved creep resistance. In an earlier report, it was shown that die cast AM60B exhibited significantly slower creep rates in compression than in tension. These results will be reviewed along with new creep results from a variety of alloys. Previously, Dargusch et al. presented evidence that dynamic precipitation of the β-Mg₁₇Al₁₂ phase affected creep behavior of magnesium alloys. In this study, an explanation for the creep strength asymmetry of die cast magnesium alloys containing aluminum will be forwarded in terms of dynamic precipitation.