Dynamic compressive mechanical behavior of magnesium-based materials: Magnesium single crystal, polycrystalline magnesium, and magnesium alloy

Abstract

This book chapter focuses on compressive mechanical behavior of magnesiumbased materials under dynamic loadings, especially high strain rate loadings. The content is organized into five sections: Section 1 provides an introduction of related literature results, Section 2 presents an overview of the split Hopkinson pressure bar technique for high strain rate tests and its fundamental data processing method, Section 3 delineates some widely used constitutive models for predicting mechanical responses of materials under high strain rate loadings, Section 4 reports the experimental results, theoretical modeling, and computational simulations of compressive dynamic mechanical behavior of magnesiumbased materials under different high strain rate loadings, and Section 5 presents the conclusions. In Section 4, three types of magnesium-based materials (i.e., magnesium single crystal, polycrystalline magnesium, and AZ31 magnesium alloy) were tested at both quasistatic and dynamic loading strain rates to investigate their compressive mechanical behavior. The employed strain rates are in the range of 0.001~3600 s-1. Theoretical stress-strain relations based on the empirical Johnson-Cook model were also derived for each type of the studied materials. The theoretically predicted stress-strain curves agree well with the experimental curves for these three types of materials. Finite element modeling was also performed to investigate the dynamic compressive behavior of the three types of the studied materials. The computational stress-strain curves match the experimental data for magnesium single crystal and polycrystalline magnesium, while a simulation was conducted to predict the compressive properties of AZ31 magnesium alloy at a randomly chosen strain rate.