Effect of structural factors on mechanical properties of the magnesium alloy Ma2-1 under quasi-static and high strain rate deformation conditions

Abstract

The elastic limit and tensile strength of deformed magnesium alloys Ma2 1 with different struc tures and textures were measured with the aim of finding a correlation between the spectrum of defects in the material and the resistance to deformation and fracture under quasi static and dynamic loading conditions. The studies were performed using specimens in the as received state after high temperature annealing and specimens subjected to equal channel angular pressing at a temperature of 250°C. The anisotropy of strength characteristics of the material after shock compression with respect to the direction of rolling of the original alloy was investigated. It was shown that, in contrast to the quasi static loading conditions, under the shock wave loading conditions, the elastic limit and tensile strength of the magnesium alloy Ma2 1 after equal channel angular pressing decrease as compared to the specimens in the as received state.

A Brief Review of Spall Failure in Pure and Alloyed Magnesium

“…2, strain rate dependent spall strength is consistently observed as the tensile deformation rate overruns the maximum speeds of activated failure mechanisms. This trend also holds for when a single study spans a wide range of strain rates for a given pure or alloyed Mg, such as in the case of 99.95% pure Mg [21], Elektron 675 [23], Ma2-1 [14], or AZ31B [13].…”

“…Garkushin et al [14,24,25] performed gas-gun studies on commercially available and ECAP Ma2-1 Mg alloy. The commercially available alloy had an average grain size of ∼ 20 μm, while the extruded alloy average grain size was ∼ 7 μm.…”

“…The conventional methods for interrogating spall strength are explosive or gas-gun-driven flyer plate impacts [13][14][15][16], though recent studies have employed laser-driven compression approaches [17][18][19]. Each method aims to achieve planar uniaxial strain compression in the region probed by rear surface time-resolved velocimetry [5].…”

Estimating Void Nucleation Statistics in Laser-Driven Spall

“…The void number density N v is estimated by looking at the mean void spacing l nn in the raw void distribution by Modeled trend in spall strength with respect to strain rate using three measured cavity number densities N v , and the critical nucleation pressure probability density (black lines). Experimental spall strength measurements on similar Mg alloys are overlaid from [41,45,46] the mean void spacing from the tomography data prescribes a wide range of N v from 6.9 × 10 13 m −3 to 3.5 × 10 16 m −3 , so each bound and the mean is plotted as lines in Fig. 8.…”

“…The grain sizes in their work also ranged between 1.5 and 5 μm. Garkushin et al [46] performed gas-gun studies on equal channel angular pressed Ma2-1 Mg alloy with a larger average grain size at ~ 7 μm with an unreported texture. Though the alloy microstructures are different from case to case, the overall trend of rising spall strength with strain rate is nicely captured by the model (overlaid on Fig.…”