The Effect of Short Duration Electric Current on the Quasi-Static Tensile Behavior of Magnesium AZ31 Alloy

Abstract

The effect of a single pulse of electric current with short duration on the quasi-static tensile behavior of a magnesium AZ31 alloy is experimentally investigated. A single pulse of electric current with duration less than 1 second is applied to the specimen, while the specimen is being deformed in the plastic region under quasi-static tensile loads. After a nearly instant decrease of flow stress at the pulse of electric current, the flow stress shows strain hardening until the failure of the specimen. The experimental result shows that the strain-hardening parameters (the strength coefficient and the strain-hardening exponent) of the hardening curve after the electric current strongly depend on the applied electric energy density (electric energy per unit volume). Empirical expressions are suggested to describe the hardening behavior after the pulse as a function of the electric energy density and are compared with the empirical expressions suggested for advanced high-strength steels.

Loading surface in the plastic and creep straining coupled with direct current

“…Experiments conducted by Nguyen with co-workers (Nguyen et al, 2016) show that a short electric impulse results in an immediate decrease in the applied stress (Fig. 1c).…”

“…where σ S is taken 180 MPa (Nguyen et al, 2016). Due to the axial symmetry of the loading surface in uniaxial tension, it is enough to provide information about the angle β 1 .…”

“…These concepts will be considered in terms of the synthetic theory of irrecoverable deformation (Rusinko andRusinko, 2009, 2011) for the case of ordinary loading and that coupled with direct current. With DC, the following phenomena are recorded and will be discussed (Andrawes et al, 2007;Chen and Yang, 2008;Kinney et al, 2009;Li et al, 2015;Perkins et al, 2007;Ross et al, 2007;Sanmartin et al, 1983;Nguyen et al, 2016;Yang and Zhao, 2010;Zhao et al, 2012Zhao et al, , 2016; Zhao and Yang, 2014):…”