Strain hardening of as-extruded Mg-xZn (x = 1, 2, 3 and 4 wt%) alloys

Abstract

The influence of Zn on the strain hardening of as-extruded Mg-xZn (x = 1, 2, 3 and 4 wt%) magnesium alloys was investigated using uniaxial tensile tests at 10-3 s-1 at room temperature. The strain hardening rate, the strain hardening exponent and the hardening capacity were obtained from true plastic stress-strain curves. There were almost no second phases in the as-extruded Mg-Zn magnesium alloys. Average grain sizes of the four as-extruded alloys were about 17.8 μm. With increasing Zn content from 1 2 to 4 wt%, the strain hardening rate increased from 2850 MPa to 6810 MPa at (σ-σ0.2) = 60 MPa, the strain hardening exponent n increased from 0.160 to 0.203, and the hardening capacity, Hc increased from 1.17 to 2.34. The difference in strain hardening response of these Mg-Zn alloys might be mainly caused by weaker basal texture and more solute atoms in the α-Mg matrix with higher Zn content.

The Evolution of Microstructure, Mechanical Properties and Fracture Behavior with Increasing Lanthanum Content in AZ91 Alloy

“…Previous studies proved that higher dislocation density and decreasing dynamic recovery of dislocations due to more solute atoms and fine precipitates could significantly enhance work hardening ability [27]. Our results confirmed that the high work hardening ability of AZ91-La alloys was primarily ascribed to the soluted La atoms in the alloy matrix [28]. Moreover, the high and balanced mechanical properties of the AZ91-La alloys were also attributed to the well-dispersed Al 3 La precipitates in micro scale, which increased the dislocation storage capability while suppressing the recovery of dislocations [8].…”

A critical evaluation of microstructure-texture-mechanical behavior heterogeneity in high pressure torsion processed CoCuFeMnNi high entropy alloy

“…The strength contribution from various strengthening mechanisms [58,59,60] like frictional stress, strain/Taylor hardening [61,62], Hall-Petch hardening [63,64], cluster strengthening [65] and solid solution strengthening [59] were calculated for Z1, Z2, Z3, and Z4 positions, as shown in Table IV. Here, we have assumed a linear superposition of all five mechanisms because the interaction between the above mechanisms in high entropy alloys is not known yet and hence their independent contribution is considered.…”

“…hardening was calculated using the formula = √ , where M is the Taylor factor, α is proportionality constant (depends on the nature of dislocation[61], 0.16 in present case), G is the shear modulus (rule of mixture), b is Burgers vector (determined from synchrotron data) and ρ is dislocation density (determined from synchrotron data). It was found that the strain hardening increases slightly from 334 to 354 MPa due slight increase in dislocation density.…”

Microstructures and Mechanical Properties of Mg–xAl–1Sn–0.3Mn (x = 1, 3, 5) Alloy Sheets

“…Magnesium alloys are the lightest structural material, which can save energy effectively and reduce environmental pollution [1][2][3]. Their good properties-low density, high specific strength/stiffness and good damping capacity-make them a potential substitute for heavier materials such as steel and aluminum [4,5].…”