Mg-Al-Si alloys are designed for creep resistance, but high Si and Al contents lead to coarse Mg2Si phases and brittle eutectic structures, compromising mechanical performance at elevated temperatures. While research often targets alloys with Si ≥ 1.0 wt.

Technologies are the enablers of the practical realization of benefits from fundamentals originating from various disciplines of science and engineering for a holistic improvement in the life of livings (plants, animal and humans all included), development of rational societies and the health of planet Earth [...]

The integration of sustainable and natural waste-derived materials into lightweight metals presents a promising strategy with both environmental and performance-related benefits. In this study, a biobased magnesium composite reinforced with dried leaf powder (DLP) derived from fallen waste leaves was synthesized using a controlled powder metallurgy method incorporating energy efficient hybrid microwave sintering, followed by hot extrusion at varying temperatures (350 degrees C, 250 degrees C, 150 degrees C). Microstructural analysis revealed that the addition of DLP had minimal effect on the overall grain morphology, while lower extrusion temperatures promoted finer grains due to restricted grain growth. Mg-5DLP composites consistently exhibited higher porosity than pure Mg, primarily due to the evaporation of organic constituents during sintering. The damping performance of the biomass-containing materials was improved (54.5% increase), particularly at lower extrusion temperatures (250 degrees C), though mechanical performance showed a trade-off with reduced hardness and compressive strength. A slight increase in yield strength at lower extrusion temperatures was attributed to retained dislocation density and grain refinement. Thermal stability remained largely unaffected, while corrosion behavior was strongly dependent on both DLP addition and extrusion temperature, with Mg-5DLP samples corroding faster than pure Mg when extruded at higher temperatures; interestingly, however, at the lowest extrusion temperature (150 degrees C), improved corrosion resistance to pure Mg (1.3 mm/year for Mg-5DLP vs. 2.0 mm/year for pure Mg) was observed. Overall, this work demonstrates that extrusion temperature is a critical factor in controlling the microstructure, thermal response, damping response, mechanical behavior and corrosion of biobased composites. The study not only highlights the potential of using direct biomass reinforcement of magnesium to synthesize lightweight, ecofriendly materials, but also lays a strong foundation for future investigations into biobased composite design, processing optimization, and property tailoring.

The development of eco-friendly magnesium (Mg)-based materials that possess acceptable mechanical properties, good biodegradability, and non-toxicity in biomedical applications has become more attractive in recent years, particularly for engineering and biomedical applications. This work investigates the effects of nano-ZnO (2 wt.%) reinforcement and cryogenic treatment (CT) on the microstructural, mechanical, thermal, and corrosion behavior of a non-toxic Mg-1Zn-1Ca alloy. Disintegrated melt deposition (DMD) was the synthesis starting point, while refrigeration at −20 °C (RF20) and liquid-nitrogen exposure at −196 °C (LN) were employed as the CT methods. CT significantly refined the grain size of the alloy and composite materials by more than 31.3%, down to 4.4–4.5 μm in diameter, leading to enhanced mechanical performance through grain boundary strengthening. RF20-treated Mg-1Zn-1Ca alloy exhibited the best damping properties (attenuation coefficient and damping capacity improved by 52.1% and 48.7%, respectively). Compressive response was also improved due to the combined effect of refined grains and reinforcement, with LN-treated Mg-1Zn-1Ca-2ZnO exhibiting the best combination of compression properties, i.e., YS—165 MPa, UCS—634 MPa, ε—43.6%, and Wf—175 MJ/m3. Ignition resistance was also improved with the addition of ZnO reinforcement (3.8% increase in ignition temperature). A significant reduction in corrosion rate was achieved with RF20 treatment, leading to corrosion rate reductions of 62% and 40% in PBS (simulated human body fluid) and salt solution, respectively, primarily due to equiaxed grains and stable microstructure. These results demonstrate the efficacy of ZnO reinforcement and CT conducted at different temperatures in selectively enhancing and tailoring the properties of eco-friendly, biocompatible Mg-alloys and composites for biomedical and strength-based applications.

As Mg-based alloys are lightweight alloys designed for the transportation industry. It is important to understand the behavior of magnesium under dynamic loading in a humid environment. Pure magnesium was synthesized by disintegrated melt deposition at 750°C. The XRD diffraction pattern revealed that the dominant orientations were (0002) and (1011) . The electrochemical tests performed using a droplet cell showed that the corrosion potential was ca. − 1.5 V versus Ag/AgCl/KCl(sat.). A cavitation-erosion test performed with a cavitating jet device showed that the main mechanism of damage was twinning and ductile fracture. Initially, deformation twins formed in grains with an orientation conducive to twinning and in direct contact with the cavitation pulse impact sites. As the test duration increased, the number of grains with deformation twins increased. Moreover, double twins, twin-twin interactions, and twin-wall intersections were formed. Twinning also caused grain fragmentation, leading to dimple formation typical for a plastic mode of fracture. In contrast, brittle fracture with lamellar facets was also revealed. After the test, the surface hardness increased 89

Overcoming the strength-ductility trade-off in biodegradable zinc alloys requires moving beyond homogeneous microstructural design. Here, we engineer a heterogeneous bimodal architecture in Zn-xAg-0.08Mg alloys by tuning Ag content with trace Mg addition. Increasing Ag to 5 wt% yields an ultrafine-grained (UFG) Zn-5Ag-0.08Mg alloy (similar to 0.2 mu m) with high strength and ductility. Further increasing to 7 wt% creates a bimodal structure where coarse-grained bands (Zn matrices with nano-AgZn3 precipitates) coexist with similar to 0.3 mu m UFG regions. Multi-scale analyses reveal that UFG regions deform via grain boundary sliding, while coarse bands act as plastic flow zones. Mechanical incompatibility between regions generates back-stress strengthening. These mechanisms enable Zn-7Ag-0.08Mg to achieve 345.2 MPa yield strength, 366.9 MPa ultimate tensile strength, and 29.96% elongation, outperforming lower-Ag counterparts. This work establishes heterogeneous bimodal structures as a promising design strategy for high-performance biodegradable zinc alloys.

A Mg-15Fe (wt.%) metal matrix composite synthesized with powder metallurgy and followed by microwave sintering was studied alongside cryogenic treatment (CT) for the first time. Results revealed that CT was able to alter the microstructure of the composite, with grain refinement (23% reduction in diameter), densification (2.0% increase), and basal texture strengthening. These resulted in enhanced thermal stability (2.4%), elastic modulus (3.2% increase), hardness (10% increase) and yield strength (7.3% increase) at the cost of reduced damping capacity (24% reduction), and ductility (15.4% reduction). Minor thermal changes were also noted of Mg-15Fe with more endothermic nature of CT treated samples. These findings showcase, for the first time, the application of CT in altering the microstructure of a Mg-based Metal-metal composite.

Strain partitioning in coarse-grained magnesium alloys is strongly influenced by crystallographic orientation and intergranular constraints. However, conventional surface-based characterization cannot directly distinguish the effects of in-plane neighboring grains from those associated with the through-thickness microstructure. In this study, AZ91 magnesium-alloy tensile specimens with controlled thicknesses were prepared to obtain single-layer, double-layer, and multi-layer grain configurations. Dual-sided electropolishing, digital image correlation, surface-morphology tracking, and quasi-in-situ electron backscatter diffraction were combined to examine the evolution of local strain, deformation mechanisms, and grain orientations during room-temperature uniaxial tension. In the examined single-layer specimens, plastic strain was strongly localized in a favorably oriented grain with a high basal-slip Schmid factor. The presence of through-thickness free surfaces facilitated strain localization and was associated with pronounced lattice reorientation toward the loading direction. Increasing the thickness while retaining a single grain layer did not eliminate this localization. In contrast, the double-layer specimen exhibited more distributed deformation and stronger intergranular interactions. The activation of individual grains could not be explained solely by their nominal basal-slip Schmid factors, indicating the importance of local stress redistribution and constraints imposed by both in-plane and through-thickness neighbors. Twin traces confined within the visible interior of some surface grains were consistent with an influence from subsurface interfaces, although their three-dimensional nucleation sites could not be determined from the present two-dimensional observations. The scatter in yield strength also decreased as the specimen thickness and number of through-thickness grain layers increased. These results provide direct experimental evidence that through-thickness grain-layer configuration affects strain partitioning, deformation-mechanism activation, and lattice-rotation behavior in coarse-grained AZ91 alloy. The proposed specimen design and dual-sided characterization strategy offer a practical approach for investigating three-dimensional intergranular constraints through coordinated surface observations.

Heterostructured materials provide a promising path to address the strength-ductility trade-off in Mg alloys. However, designs relying solely on grain size heterogeneity often yield limited improvements. Herein, we fabricated multiscale heterostructures in an AZ91 alloy, featuring twin-modified coarse grains and precipitate-hardened fine grains, through a combination of pre-aging, extrusion, and pre-compression treatments. The obtained material exhibits an exceptional strength-ductility combination, outperforming most existing AZ91 alloys. Mechanistic investigations reveal that this favorable combination is primarily driven by enhanced hetero-deformation induced (HDI) strengthening and hardening, which result from the accumulation of geometrically necessary dislocations (GNDs) at multiscale interfaces. Additional contributions arise from twin-matrix interactions that activate non-basal slip systems, as well as a composite strengthening effects induced by precipitates, dislocation cells, and stacking faults. The multiscale heterostructures promote uniform deformation through slip transfer, stress redistribution, and strain delocalization. Strain hardening is initially dominated by HDI effects, while traditional dislocation-mediated mechanisms become predominant at larger strain. The present approach, integrating precipitate engineering, grain size control, and crystallographic design, provides general guidelines for developing advanced lightweight materials.

Mg has high potential as a base metal for biocompatible metallic implants due to its light weight, biocompatibility, and mechanical properties that are similar to bone. In the present study, Mg-10Se was synthesized via a powder metallurgy method followed by cryogenic treatment (CT). It was found that cryogenic exposure to −20 °C (RF20) resulted in the best combination of damping properties (38.5% and 12.1% gains in attenuation coefficient and damping capacity, respectively) and compressive yield strength (16.7%), while liquid nitrogen (LN) treatment (−196 °C) resulted in the best ultimate compressive strength (10% increase to 260 MPa), energy absorbed during compressive testing (17.5% increase to 40 MJ/m3), and optimal corrosion rate (reduction of 59.7% to 0.273 mm/year). This study clearly highlights the role and importance of not just compositional control in improving properties but that of cryogenic treatment temperature to selectively enhance the individual properties of metallic materials to best meet end application requirements.

Magnesium-based nanocomposites are a class of biomaterials that can be used as orthopaedic im-plants. However, these bio-implants often encounter friction during the motion of the human body, which is referred to as tribocorrosion. In this work, pure magnesium (Mg) and Mg-CaO nanocom-posites were synthesized through disintegrated melt deposition (DMD) process with distinct weight percentages (0.5-2.0 wt%). The microstructural evolution of the developed materials before and after the tribocorrosion test was characterized using scanning electron microscopy (SEM) combined with Energy Dispersive X-ray Spectroscopy (EDS) and Transmission Electron Microscope (TEM). Subsequently, Mg-0.5 CaO displayed better tensile strength with enhanced ductility compared with the other variants. The tribocorrosion tests were performed in Ringer's medium. Accordingly, two different applied loads (2N and 5N) were used at a fixed frequency (3 Hz) and stroke (5 mm) to facilitate the test. XRD and Raman spectroscopy analyses were performed to identify the corro-sive products such as Mg(OH)2 and CaCO3 present on the surface of the materials. The results indicated that under both the applied loads, the tribocorroion rate of Mg-0.5 CaO composite was lower than the other composite variants.

The rolled (R sample) and extruded (E sample) AZ31 alloys show different texture characteristics, exhibiting a strong basal texture and a transverse direction-split texture, respectively. The increased crystallographic orientation heterogeneity in the E sample enhanced resistance to slip transfer, leading to a more pronounced slip accumulation at the grain boundaries between adjacent grains. This resulted in a higher hetero-deformation induced (HDI) stress in the E sample compared to the R sample. The enhanced yield strength observed in the E sample can be ascribed to the elevated Hall−Petch slope value, which was a consequence of the reduced geometrical compatibility factor. Meanwhile, more significant HDI strengthening and hardening effects synergistically improved both strength and ductility. Notably, high grain boundary misorientation angle contributed to the activation of non-basal slips, thereby alleviating local strain concentration near the grain boundary and improving the work hardening ability.

Combining waste materials with lightweight sustainable materials in higher-value applications offers an appealing pathway for future materials design. This combines energy savings with recycling which are of great emphasis in today’s energy and resource-intensive world. Notably, incorporation of biomass to metallic materials has not been explored. In this work, a first-time investigation of direct biomass (fallen waste mango leaves) integration into metallic magnesium is explored, resulting in a novel metal + biomass composite possessing minimal compromise in mechanical response (by 7.9

This study compares the microstructural and mechanical properties of Mg-10Y alloy synthesized via two different processing routes: vacuum die (VD) casting and disintegrated melt deposition (DMD) process. The analysis through scanning electron microscopy (SEM) and 3D X-ray microscopy (XRM) revealed that the alloy processed through DMD exhibited a higher fraction of eutectic Mg24Y5 phase as compared to the alloy processed through VD casting. Although the individual Mg24Y5 phase in both the alloys exhibited a partially divorced eutectic morphology, the divorced degree (D-d) for DMD processed alloy was similar to 60% higher than the D-d of alloy synthesized through VD casting due to the higher cooling rate in the former. Both hardness and yield strength (YS) of the DMD processed alloy was found to be higher than VD processed alloy, which has been predominantly attributed to the significantly smaller grain size in the former (similar to reduction by 83.5%). In addition, ultimate compressive strength (UCS) and UCS/YS were also found to be higher for the DMD processed alloy. The addition of 10 wt% Y was found to significantly improve the ignition temperature as compared to other as-cast Mg alloys and the strength was further improved by using DMD method, giving advantage over VD casting.

Tension twinning with a negative Schmid factor was extensively activated when a [0002]perpendicular to extrusion direction (ED) textured magnesium rod was subjected to tension along the ED (hard-orientation loading). Notably, 84.5 % of these non-Schmid twinning (NST) events occurred at grain boundaries with misorientation angles exceeding 30 degrees The underlying mechanism was examined by establishing a quantitative relationship between intergranular misorientation and the strain compatibility factor for slip-twinning transfer. Enhanced slip-twinning transferability at grain boundaries with relatively high misorientation angles was identified as the key factor governing this behavior. The NST behavior is beneficial for bulk plastic deformation by alleviating high local stresses induced by dislocation pile-ups at grain boundaries.

There is growing emphasis on lightweight and energy-efficient metallic materials, with multicomponent alloying (MCA) being one strategy to achieve this. This was combined with the inherently lightweight magnesium (Mg) as the base metal. Two Mg-based MCAs, namely Mg-71MCA and Mg-80MCA (Mg-10Li-9Al-6Zn-4Si and Mg-10Li-6Al-2Zn-2Si, respectively, wt.%), with density in the range of 1.55-1.632 g/cc akin to plastics were synthesized via the Disintegrated Melt Deposition method in this work. The effects of cryogenic treatment (CT) at -20 °C, 80 °C, and -196 °C (LN) on the physical, microstructural, thermal, and mechanical properties were systematically evaluated. CT resulted in densification, significant grain refinement (up to a 27.9% reduction in grain diameter after LN treatment), alterations in crystallographic texture, and notable changes to secondary phases-namely, an increased precipitate area fraction. These led to enhanced mechanical performance such as damping capacity, microhardness, and compressive response (most apparent for Mg-71MCA with 12.1%, 6.7%, and 1.6% increase in yield strength, ultimate compressive strength, and energy absorbed, respectively, after RF20 treatment), coupled with exceptional ductility (>80% strain without fracture), which is superior to pure Mg and commercial Mg alloys. Overall, this work showcases the potential of MCAs compared to existing conventional lightweight materials, as well as the property-enhancing/tailoring effects brought upon by different CT temperatures. This highlights the multi-faceted nature of material designs where compositional control and judicious processing parameter selection need to be both leveraged to optimize final properties, and serves as a baseline for further lightweight MCA development to meet future needs.