On the kinetics of texture development in Al-Mg alloy under high strain rate tension

Abstract

In this work, the texture development in Al-4%Mg alloy sheet material under high strain rate (HSR) tensile deformation at 3.1 × 103 s−1 is studied using split Hopkinson tension bar test. Quantitative analysis of texture evolution for three different strain levels is carried out through strain mapping using digital image correlation and subsequent characterization using X-ray diffraction. Critical comparisons to the texture development in the sample deformed at quasi-static rate are made concurrently. The results show that Cube and Copper components strengthen upon tensile deformation under both the loading rates. However, the characteristics of lattice rotation, rotation path, lattice rotation rate and strength of texture components under HSR deformation are significantly different from that under quasi-static loading. Although the deformation texture developed at HSR is relatively weak, Copper component is noted to evolve sharply amongst other texture components. Further, the electron backscatter diffraction measurements reveal that the dislocation density and intragranular misorientation developed under HSR tension are relatively lower than at quasi-static rate for comparable strains. The inclusive analysis of results obtained reveals that texture weakening in Al-Mg alloy under HSR tension occurs as a result of relatively higher strain hardening and absence of dynamic strain aging.