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This study investigates the effects of zinc (4 wt.%) and severe plastic deformation on the mechanical properties of AZ61 magnesium alloy through the stir-casting process. Severe plastic deformation (Equal Channel Angular Pressing (ECAP)) has been performed followed by T4 heat treatment. The microstructural examinations revealed that the addition of 4 wt.% Zn enhances the uniform distribution of β-phase, contributing to a more uniformly corroded surface in corrosive environments. Additionally, dynamic recrystallization (DRX) significantly reduces the grain size of as-cast alloys after undergoing ECAP. The attained mechanical properties demonstrate that after a single ECAP pass, AZ61 + 4 wt.% Zn alloy exhibits the highest yield strength (YS), ultimate compression strength (UCS), and hardness. This research highlights the promising potential of AZ61 + 4 wt.% Zn alloy for enhanced mechanical and corrosion-resistant properties, offering valuable insights for applications in diverse engineering fields. [ABSTRACT FROM AUTHOR]

We studied the hydrogen storage properties of commercial AZ31 and AZ91 magnesium alloys with refined microstructure. Various processing techniques, such as equal channel angular pressing (ECAP) and high energy ball milling (HEBM), were utilized to modify the microstructure and phase composition of the alloys. X-ray diffraction (XRD), scanning electron microscopy (SEM), and optical digital microscopy (ODM) were utilized to characterise the microstructure and phase transformations during the hydrogen absorption/desorption processes. The isothermal kinetics are measured by a Sieverts'-type apparatus at the temperature of 350 ℃. In the ECAP process, the AZ31 alloy had a slightly higher storage capacity and faster absorption kinetics, absorbing 6.0 wt% (6.6 wt% - maximum) of hydrogen in less than 12 min. In the HEBM process, AZ91 absorbed 6.5 wt% of hydrogen and desorbed it in 347 ± 13 s, a faster rate than AZ31. The pressure–composition isotherms of all studied alloys at a temperature of 300 °C were determined. The processed alloys exhibited no pressure hysteresis. The microstructure of bulk samples and the morphology of prepared powders were shown to affect their hydrogenation behaviour. The activation energies for hydrogen desorption were 119 ± 2 kJ/mol for AZ31 alloy processed by ECAP and 128 ± 3 kJ/mol for AZ91 alloy processed by HEBM, which are significantly lower than the activation energy values of pure Mg hydride. • Hydrogen storage properties of commercial AZ31 and AZ91 alloys are studied. • The ECAP and HEBM processes were employed to enhance hydrogen storage performance. • Both processes significantly improved the kinetic and thermodynamics properties. • The processed alloys exhibited no pressure hysteresis • The activation energies reduced to 119 ± 5 kJ/mol for AZ31-ECAP and 128 ± 5 kJ/mol for AZ91-HEBM. [ABSTRACT FROM AUTHOR]

Magnesium is the lightest metal and is extensive in the structural application. The metal matrix composites are developed to improve the strength of magnesium alloys. In this research, AZ91 alloy reinforced with 1 wt% WS 2 was produced using stir casting process. The composite was homogenized for 24 h at 410 °C and subsequently aged for 10 h at 200 °C. The severe plastic deformation was performed using equal channel angular pressing (ECAP). The phase composition was analyzed using X-ray diffraction techniques. The microstructure, fractography, and mechanical properties of ECAPed composites have been investigated using scanning electron microscope, and universal testing machines, respectively. The results indicate that B-phases are present in the form of particles inside and at grain boundaries in annealed composites, which are refined to needle-shaped precipitates at grain boundaries, and grains size is refined to 0.2 μm after 4passes of ECAP. Microhardness and tensile yield strength are proportional to the number of passes, and 20.45% and 103.5% are increased respectively after 4pass. The UTS was found to be maximum (324.8 MPa) for 4P WS 2 /AZ91. Fractography analysis revealed that plastic fracture in annealed and elastic-plastic fracture occurred after 4P WS 2 /AZ91 MMC. • WS 2 /AZ91 (MMCs) were manufactured by stir casting method and subsequently annealed are deformed by ECAP. • ECAP effects on microstructure and mechanical behavior of WS 2 /AZ91 MMCs have been investigated. • The relation between number of passes and strength has been established. • The investigations reveal that 4pass-WS 2 /AZ91 exhibits maximum hardness and ultimate tensile strength. [ABSTRACT FROM AUTHOR]

AZ91 reinforced with four different concentrations (0,0.3,0.6,1)wt% of WS 2 micro particles were fabricated using stir casting method. The samples were deformed by equal channel angular pressing (ECAP) after homogenization. The scanning electron microscopy and X-ray diffraction were used to investigate the microstructure and phase composition respectively. The results reveal that rod-like precipitates produced during the homogenization process are refined and bounded in the grain boundaries by the combined effect of WS 2 enrichment and increasing number of passes of ECAP. The needle precipitates are eminent in 1pass 0.3 wt%WS 2 /AZ91. The β-Mg 17 Al 12 and extracted Al particles are dissolved and secondary phases are produced by dynamic recrystallization after 2pass 1 wt%WS 2 /AZ91. The maximum crystallite size and microstrain distribution have been observed for 1pass 0.6 wt%WS 2 /AZ91. The mechanical properties investigation represents that 2pass 0.6 wt%WS 2 /AZ91 has optimal yield strength and ultimate tensile strength. The (22.143)%, (44.735)% and (92) % increment in yield strength, ultimate tensile strength and elongation have been observed in 2pass 1 wt%WS 2 /AZ91 compared with homogenized monolithic AZ91 alloy respectively. The maximum young's modulus (6696.218MPa) has been found for 1pass homogenized WS2/AZ91 and minimum (4108.165MPa) for homogenized 0.6 wt%WS 2 /AZ91. The ECAP deformed 1pass 0.3 wt%WS 2 /AZ91 exhibits the maximum strain hardening rate. The YTS, UTS, and elongation are (30.41) %, (47.6) % and (51.9)% increased after 2pass-0.6 wt%WS 2 /AZ91. [ABSTRACT FROM AUTHOR]