Influence of Strain Rate and Stress State on the Mechanical Behavior of Die-Casting AM60 Magnesium Alloy

Abstract

This paper presents experimental study, including the test method and the test data analysis, on the die-casting AM60 magnesium alloy material. Uniaxial tension tests were carried out at various strain rates roughly from 5 × 10−4 to 1 × 102 s−1, which are of interest in vehicle crash CAE. Uniaxial compression and shear tests at strain rates from 5 × 10−4 to 5 × 10−2 s−1 were also carried out. All the specimens were cut off from die-casting plates of AM60 with thickness of 2.6 mm. The test results show that the yield stress of die-casting AM60 increases slightly with the strain rate at uniaxial tension. However, this tendency is not very significant due to the relatively large variation among the tests. There is no obvious relationship between the fracture strain and the strain rate at uniaxial tension and compression. For shear, the fracture strain decreases with higher strain rate. It is verified that this material follows the von-Mises yield criterion, with nearly symmetrical yielding behavior between uniaxial tension and compression at the same level of strain rates. And it is shown that the equivalent fracture strain or effective ultimate strength at uniaxial tension and shear states is relatively close to each other, which is significantly smaller than those at compression. According to these results, it is necessary to perform further study with additional tests at other stress states for accurately characterizing the fracture behavior of the die-casting AM60 magnesium alloy.