Mechanical Properties Of As-extruded Mg Research Articles

Influence of Y on the phase composition and mechanical properties of as-extruded Mg–Zn–Y–Zr magnesium alloys

The influence of Y on the microstructure, phase composition and mechanical properties of the extruded Mg–6Zn–xY–0.6Zr (x = 0, 1, 2, 3 and 4, in wt%) alloys has been investigated and compared by optical microscopy, X-ray diffraction, scanning electron microscopy, energy dispersive X-ray spectrometer and tensile testing. The increase in Y content has shown grain refinement effects on the microstructure morphologies of the extruded alloys. However, when the content of Y exceeds 2.2 wt%, the grain refinement effect of the Y is not obvious any more with the increase of the Y content. The quasicrystal I-phase (Mg3YZn6), face-centred cubic structure W-phase (Mg3Y2Zn3) and a long period stacking ordered (LPSO) X-phase (Mg12YZn) can precipitate in different ranges of Y/Zn ratio (in at.%) when the Y content in the Mg–Zn–Y–Zr alloys is varied. Comparison of the mechanical properties of the alloys showed that the different ternary Mg–Zn–Y phases have different strengthening and toughening effects on the Mg–Zn–Y–Zr alloys in the following order: X-phase > I-phase > W-phase > MgZn2.

Preparation and properties of Mg–Cu–Mn–Zn–Y damping magnesium alloy

Abstract This paper presents the successful preparation of a high-damping, high-strength Mg–Cu–Mn–Zn–Y alloy by alloying and extrusion. The damping capacity of the as-cast Mg–3Cu–1Mn alloy (alloy 1) displayed evident variations with changes in Y and Zn content. The as-cast Mg–3Cu–1Mn–2Zn–1Y alloy (alloy 2) exhibited excellent damping capacity and unusual damping growth in the high-strain amplitude stage; the damping capacity of alloy 2 exceeded that of alloy 1 and even approached that of pure Mg when the strain amplitude exceeded 5 × 10 −4 . This observation is believed to be related to the formation of long and parallel dislocation configurations and the interactions between these dislocations and plastic second-phase particles. The study also showed a remarkable improvement in the mechanical properties of as-extruded Mg–Cu–Mn–Zn–Y alloys. We attribute this finding to dynamic recrystallization, dispersion strengthening, and work hardening during hot extrusion.

Effect of Zr addition on the mechanical properties of as-extruded Mg–Zn–Ca–Zr alloys

Extrudable Mg–6Zn–0.2Ca(–0.8Zr) alloy (mass%) has been developed. The Mg–Zn–Ca–Zr alloy shows excellent mechanical properties in the as-extruded state with the ultimate tensile strength of 357 MPa and elongation to failure of 18%. These properties are related to dynamic recrystallization, texture and precipitation. Dynamically recrystallized grains are pinned by fine precipitates, resulting in very fine grain size. The extruded sample also exhibits a higher average {0 0 0 2} 〈 1 1 2 ¯ 0 〉 Schmid factor due to the presence of unrecrystallized regions, leading to texture strengthening. Zr may work as a microalloying element, resulting in fine and dense distribution of a MgZn 2 based phase involving Ca and Zr.