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We investigate the glassy-state properties of Mg2Ca, Al2Ca, and Al4Ca from the grafting application viewpoint. We employed classical molecular dynamics to examine the phase transition, structural, thermodynamic, transport, and mechanical properties in the amorphous state. All properties suggest successful simulations of the glass phase at and below the glass transition temperature, ranging between 550 and 689 K for Mg2Ca, Al2Ca, and Al4Ca. Computed results are compared and discussed with the reported findings and known mechanical and thermal properties of the various parts of the human bones and biocomposites. The comparison establishes that the mechanical, thermal, and transport properties significantly improve in the glass phase compared to its crystalline alloy form. At 300 K, studied glasses have densities in close agreement with human bone density. Structural analysis and heat capacity show the second-order phase transition, verifying the formation of the glass structure. The targeted glasses exhibit excellent thermal conductivity and thermal diffusivity compared to other commonly used biocomposites for bone grafting. Furthermore, the simulated elastic properties, viz., the Poisson ratio, G/B ratio, Cauchy's pressure, and yield strength, are in close agreement with the mechanical properties of various parts of human bone. The predicted ductility nature, contrary to the brittle character of Mg2Ca, Al2Ca, and Al4Ca crystalline alloys, proves the superiority of the glassy form for the implant's functioning. The minimum enthalpy of formation and thermodynamic stability of studied compounds benefit the synthesis process; hence, we propose that the studied glasses are persuasive materials for experimental synthesis aimed at bone grating applications. [ABSTRACT FROM AUTHOR]

Magnesium alloys have gained attention as potential biodegradable metallic biomaterials due to their mechanical properties akin to human bone. However, their rapid corrosion within the body prior to full bone fracture healing presents a significant challenge. Hence, our study aimed to address their drawbacks by employing a cerium oxide/merwinite nanocomposite coating. In this investigation, we sought to enhance corrosion resistance and antibacterial properties by depositing a porous cerium oxide layer onto AZ31 magnesium alloy via plasma electrolytic oxidation (PEO), while improving biocompatibility through a secondary merwinite silicate coating applied via electrophoretic deposition (EPD). Surface morphology and chemical composition were analyzed using Field Emission Scanning Electron Microscopy (FE-SEM) and Energy Dispersive Spectroscopy (EDS) pre- and post-immersion in Simulated Body Fluid (SBF). Coating phases were examined through X-ray Diffraction (XRD), antibacterial efficacy was evaluated via viable cell counts in contact with Escherichia coli (gram-negative) and Staphylococcus aureus (gram-positive), and corrosion resistance was assessed using Electrochemical Impedance Spectroscopy (EIS) and Potentiodynamic Polarization (PDP) tests following SBF immersion. Furthermore, adhesion and toxicity were investigated to assess biocompatibility. The findings revealed that the composite coating exhibited a higher calcium-to-phosphate ratio (Ca/P = 1.31) along with enhanced cell adhesion, increased cell viability, reduced toxicity, and 99.99 % antibacterial activity. [ABSTRACT FROM AUTHOR]

In this article, dissimilar magnesium and aluminum alloys were welded with a Zn interlayer and TiC nanoparticles by friction stir welding. Optimal joining conditions were achieved by a combination of three traverse speeds (30, 45, and 60 mm/min) and constant rotational speeds (1050 rpm). The best microstructure evolution and mechanical properties were achieved for specimens joined at rotational and traverse speeds of 1050 rpm and 45 mm/min, respectively. The grain size decreases as the traverse speed increases from 30 to 45 mm/min due to a reduction in heat input, an improvement in reinforcing distribution, and high intermixing of materials, then increases from 45 to 60 mm/min due to inadequate heat input for recrystallization process. It was shown that the TiC particles play a prominent role in the microstructure modification and enhance mechanical properties of weld samples while the Zn foil interlayer plays a vital in avoiding the formation of Al-Mg IMC phases. The obtained result under optimal welding parameters indicates that MgZn2, Mg-Al-Zn compounds, Mg and Al solid solution, were the main detected common phases in the stir zone instead of the brittle and hard Al-Mg IMCs formation. The average hardness values of 232 Hv were achieved, while the strength of the weld specimen experiences the 189 MPa value. In addition, a combination of brittle and ductile modes was observed based on the fracture surface of the weld sample after the tensile test. [ABSTRACT FROM AUTHOR]

This study, aims to weld the 5.2 mm thick AZ31 magnesium alloy with conventional friction stir welding at the highest joining efficiency. As a result of the experiments, 88% joining efficiency in tensile strength has been obtained at 1250 rpm, 400 mm.min−1 welding parameter. As a result of micro–macrostructure photographic examinations of the samples joined with these parameters, it is seen that the joining is fully realized. Samples joined with these parameters have been used in fatigue tests. According to the strain‐controlled low cycle fatigue test results performed on welded and base metal samples, the base metal samples have exceeded the 50,000‐cycle limit without failure, with an elongation rate of 0.3%, and the welded samples with an elongation rate of 0.2%. Low cycle fatigue parameters of welded and base metal samples have been obtained according to the Coffin‐Manson‐Basquin equation. Highlights: In joining AZ31 alloy with FSW, a high joining efficiency of 88% was achieved.Similar fatigue test results showed that the weld quality was retained along the joint.Coffin‐Manson‐Basquin equation constants were determined. [ABSTRACT FROM AUTHOR]

Hydrogen is a promising candidate for green energy sources for future endeavors because of its abundance on Earth. Although its storage is a major challenge for the researchers of this era because of its unsafe and highly explosive nature. The structural, optoelectronic, thermoelectric, vibrational, thermodynamic properties and hydrogen storage capacity of XMgH3 (X = Sr , Ba) are carried out by using the full potential linearized augmented plane wave (FP-LAPW) method in the DFT framework. The theoretical study about these magnesium-based metal hydride perovskites, i.e., SrMgH3 and BaMgH3, declares them structurally stable compounds in space group Pm-3m. The optimization graph for SrMgH3 and BaMgH3 reflects the lowest ground state energy, i.e., −6759 Ry and −16683 Ry, respectively. Comparatively, BaMgH3 seems to be more stable. The electronic band structures and density of states declare them pure metallic due to zero band gap and overlapping of electronic states of the valence and the conduction bands. The electrical conductivity of BaMgH3 increases up to 4. 5 × 1 0 2 0 (Ω ⋅ m ⋅ s) − 1 and thermal conductivity 1. 2 5 × 1 0 1 6 (Ω ⋅ m ⋅ s) − 1 in the temperature range 100 K to 1000 K revealing the good metallic character of BaMgH3. The optical analysis portrays the absorption of compounds in the visible range along with valance shell electrons to the weak bond of hydrogen and dissociates hydrogen molecules at a certain intensity of light. BaMgH3 compound shows minimum scattering and maximum absorption of light in the visible region up to 3 eV. The reflectivity peaks in the visible region 3.0 eV show that 40% of light energy is absorbed due to the opaque nature of BaMgH3. Both these compounds are declared thermodynamically stable due to negative free energy such as −1.20 eV for SrMgH3 and −1.50 eV energy for BaMgH3 at 1000 K, respectively. Moreover, the three acoustic modes showing zero imaginary phonon frequencies at Γ symmetry points predict these compounds' structural and thermodynamical stability. The gravimetric hydrogen storage concentration of SrMgH3 and BaMgH3 is determined as 2.637% and 1.836%, respectively. [ABSTRACT FROM AUTHOR]

Optimization for hydrogen storage properties of Mg-based alloy is mainly restricted by coarse α-Mg grains and uneven catalytic phases. In this study, a strategy of melt-spinning rapid solidification is proposed to fabricate one-dimensional Mg 97 Ni 2 Y 1 alloy fiber with submicron-sized α-Mg grains and uniform microstructure. After heat treatment and activation process, ultrafine Mg 2 Ni and YH 2 phases are in-situ generated and uniformly distributed. The results indicate that 5.24 wt% H 2 is absorbed at 305 °C in 30 min, higher than the as-cast alloy powder of 4.49 wt% H 2. Meanwhile, the dehydrogenation rate is accelerated at lower temperatures. Based on the DSC curve, the hydrogen pumping effect in the fiber alloy powder is more significant, reducing the dehydrogenation temperature of MgH 2. The fiber alloy powder absorbs more hydrogen in stage 1, leading to enhanced hydrogenation kinetics. The uniform and refined microstructure formed by the rapid-solidified fiber is the key factor for enhanced de-/hydrogenation properties. • Submicron α-Mg grains are formed in Mg–Ni–Y alloy fiber by melt-spinning. • Nano Mg 2 Ni and YH 3 multiphases are uniformly precipitated by H-induced reaction. • The F-powder absorbs 5.24 wt% H 2 at 305 °C since more absorbed H 2 in stage 1. • The initial decomposition temperature of F-powder hydrides is reduced to 243.8 °C. [ABSTRACT FROM AUTHOR]

In this study, we utilized Selective Laser Melting (SLM) technology to fabricate a magnesium alloy, and subsequently subject it to micro-arc oxidation treatment. We analyzed and compared the microstructure, elemental distribution, wetting angle, and corrosion resistance of the SLM magnesium alloy both before and after the micro-arc oxidation process. The findings indicate that the SLM magnesium alloy exhibits surface porosity defects ranging from 2% to 3.2%, which significantly influence the morphology and functionality of the resulting film layer formed during the micro-arc oxidation process. These defects manifest as pores on the surface, leading to an uneven distribution of micropores with varying sizes across the layer. The surface roughness of the 3D-printed magnesium alloy exhibits a high roughness value of 180 nanometers. The phosphorus (P) content is lower within the film layer compared to the surface, suggesting that the Mg3(PO4)2 phase predominantly resides on the surface, whereas the interior is primarily composed of MgO. The micro-arc oxidation process enhances the hydrophilicity and corrosion resistance of the SLM magnesium alloy, thereby potentially endowing it with bioactivity. Additionally, the increased surface roughness post-treatment promotes cell proliferation. However, certain inherent defects present in the SLM magnesium alloy samples negatively impact the improvement of their corrosion resistance. [ABSTRACT FROM AUTHOR]

Although rare-earth magnesium (Mg-RE) alloys are widely used in various industries, they show much poorer machinability for shaping into desired dimensions than conventional magnesium ones. The most critical issues associated with cutting Mg-RE alloys are high risk of chip ignition and short tool life dominating the chip removal process. The present paper aims to address the tool performances on the machinability of Mg-RE alloys under dry cutting. Four types of tools covering uncoated and diamond-coated ones were examined, and a special focus was devoted to explore the effects of various tool parameters on the milling responses of Mg-RE alloys as well as the underlying wear mechanisms. The experiments reveal that the cutting tools with larger rake, clearance, and helix angles can achieve high-quality milling of Mg-RE alloys at controllable cutting temperatures. The cutting parameters can be maintained at a certain level, such as the cutting speed of 120–240 m/min and the feed per tooth of 0.1–0.2 mm/z, to meet the requirements of safe milling of Mg-RE alloys without ignition risk. [ABSTRACT FROM AUTHOR]

The fabrication of hydroxyapatite (HAP)/MgO composite coatings on Mg alloy is crucial for enhancing the corrosion resistance and biocompatibility of biomedical implants. In this study, we aimed to investigate the effects of two different surface modification methods, i.e., electrochemical (electrodeposition, ED) and chemical (solution treatment, ST), on the phase structure, degradation properties, and biocompatibility of the composite coatings in comparison to the anodized coating. The surface morphologies and crystalline structures of the coatings were characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD). Subsequently, the degradation rate of the coatings in simulated body fluid were comprehensively evaluated by using electrochemical impedance spectroscopy (EIS), potentiodynamic polarization and scanning electrochemical microscopy (SECM) tests. Additionally, in-vitro cell proliferation assays were employed to quantitatively assess the biocompatibilities of the coatings. The results showed that both ED and ST methods were effective in depositing HAP on anodized Mg alloy, resulting in different surface morphologies with hydroxyapatite layer thicknesses of 2.71 μm and 3.56 μm, respectively. In this way, the HAP-deposited coatings exhibited improved corrosion resistances and biocompatibilities compared with those of the anodized coating. Specifically, the ST-deposited composite film displayed superior degradability and biocompatibility which was attributed to its filiform surface morphology and thicker HAP layer. Overall, the present study demonstrates the potential of HAP/MgO composite coatings for biomedical applications, with implications for the development of advanced implant materials with improved performance and biocompatibility. [ABSTRACT FROM AUTHOR]

Alloying represents an effective approach for addressing challenges related to over stable thermodynamics and slow kinetics in magnesium alloys. The incorporation of Y dopant served to enhance the quantity of grain boundaries and phase boundaries, thereby addressing the issue of high dehydrogenation temperature observed in Mg85–Ni10–La5, which can be decreased to 273.3 °C after the addition of 0.5 wt% Y additive. In addition, the initial hydrogenation rate of Mg85–Ni10–La4.5-Y0.5 reached up to 3.42 wt% H 2 at 260 °C and the apparent activation energy for dehydriding was decreased from 115.31 to 86.05 kJ/mol. Theoretical calculations suggested that the hydrogen adsorption energy of Mg85–Ni10–La4.5-Y0.5 was dramatically lower than that of Mg85–Ni10–La5, improving hydrogenation properties. The consistency between theoretical calculations and experimental outcomes provided a valuable reference for the selection of suitable magnesium-based hydrogen storage materials. [Display omitted] • Mg85–Ni10–La4.5-Y0.5 can absorb 3.42 wt% H 2 at 260 °C within a minute and release 4.67 wt% H 2 at 300 °C within 5 min. • The peak desorption temperature of Mg85–Ni10–La4.5-Y0.5 is 273.3 °C. • The activation energy of dehydrogenation of Mg85–Ni10–La4.5-Y0.5 is 86.05 kJ/mol. • The diffusion rate of H is faster in Mg85–Ni10–La4.5-Y0.5, therefore Mg85–Ni10–La4.5-Y0.5 is easier to adsorb hydrogen. [ABSTRACT FROM AUTHOR]

Biodegradable materials such as magnesium and its alloys have significant potential for realizing biomedical advancements; however, their rapid degradation in biological settings restricts their widespread use. A metal–organic-like metallic ion-integrated tannic acid (TA) complex coating was immobilized on the surface of the rare earth element-free Mg–2Zn–1Mn (ZM21) magnesium (Mg) alloy for improving the corrosion resistance. The TA was first immobilized on an Mg substrate, followed by an alternating dip-coating process of Ce ions and TA to build a complex coating. Such immobilization process was executed by the chelation reaction between TA molecules and metallic ion. The EIS results show that after 7 days of immersion in SBF solution, the impedance module value of the Mg–TA/Ce coating at 0.01 Hz still remains at 104 Ω cm2, and its tensile strength decreased by 2.1%, demonstrating its excellent corrosion resistance. This metal–organic coating also induces the proliferation of osteoblast and fibroblasts cells. This metal–organic complex coating can serve as a viable means for modifying magnesium-based orthopedic implants. [ABSTRACT FROM AUTHOR]

There has been a good deal of research on improving the corrosion behavior of magnesium (Mg) by polycaprolactone (PCL) coating, albeit with destroying bioactivity and hydrophilicity. The adhesion of a polymeric layer to the surface of the metal is also a knotty problem. On the other hand, the micro-arc oxidation (MAO) process is a new method that can create thin films with desirable adhesion to the surface of the implants although these films could hardly control the degradation of Mg. In this research, a multifunctional nanocomposite coating showing significant adhesion to the surface of the substrate has been fabricated that can enhance not only the corrosion but also the bioactivity of Mg-based biomaterials. It can also improve their biological, antibacterial, and osteogenesis properties. The fabrication process of this multifunctional composite coating with these desirable features can be broadly separated into three main stages beginning with synthesizing strontium (Sr) and copper (Cu) doped bioactive glass nanoparticles (BGNs), applying micro-arc oxidation (MAO) nanocomposite coating on the surface of pure Mg, and finally sealing the pores of MAO layer by PCL with BGNs containing Sr and Cu at concentrations of 5, 10, and 15 wt%. After this process, the corrosion resistance, bioactivity, antibacterial, and cytotoxicity of Mg-based samples were assessed. It was found that the addition of 10 wt% of BGNs in the MAO-PCL nanocomposite enhanced corrosion resistance (78,343.358 KΩ.Cm2), bioactivity, cellular viability and antibacterial property (99%) of Mg-based scaffolds, which can be widely used in bone tissue engineering. [ABSTRACT FROM AUTHOR]

The biodegradability of magnesium (Mg) metal implants necessitates surface modification to mitigate the high corrosion rate in the body's physiological environment. This study focuses on synthesizing and applying a nanocomposite coating of polydimethylsiloxane-nanosized bioactive glass (PDMS-nBG) on the surface of a plasma electrolytic oxidation (PEO)-modified AZ91 Mg alloy. The PDMS-1 wt% nBG nanocomposite coating was deposited on the PEO-treated substrate using the dip-coating method. Surface and cross-sectional morphologies of the nanocomposite coatings were examined using field emission scanning electron microscopy (FESEM). Corrosion behavior of the AZ91 substrate, PEO coating, and double-layer PEO/PDMS-nBG coating was investigated using electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization (PDP) tests. Results showed that the corrosion resistance and corrosion current density of Mg substrates increased and decreased from 4815 Ω.cm2 and 8.96 µA.cm− 2 to 18 MΩ.cm2 and 0.00016 µA.cm− 2 for AZ91 and PEO/PDMS-nBG coating, respectively. Additionally, the morphology and adhesion of cultured human mesenchymal cells on the PEO-modified AZ91 substrates with a single PDMS polymer coating and a PDMS-nBG nanocomposite coating were investigated using fluorescent light microscopy and FESEM. The PEO/PDMS-nBG bilayer coating effectively addressed the limitations of magnesium alloys and holds potential for biomedical applications, particularly in orthopedic implants, due to the enhanced biocompatibility and bioactivity of Mg alloys. [ABSTRACT FROM AUTHOR]

This document is a summary of a special issue of the journal "Materials" titled "Development of Advanced Aluminum and Magnesium Alloys: Microstructure, Mechanical Properties and Processing." The special issue focuses on the latest progress in the development of advanced aluminum alloys, magnesium alloys, and their composites. Thirteen articles are included in the special issue, with six papers on aluminum alloys, two papers on magnesium alloys, and five papers on light metal composite materials. The articles cover a range of topics including optimization of aluminum alloys for casting processes, the effect of torch angle on the properties of aluminum alloys fabricated using additive manufacturing, and the development of high-strength aluminum metal-matrix composites. The special issue provides valuable insights into the relationships between microstructure, mechanical properties, and processing conditions, and aims to contribute to the future development and industrial applications of lightweight alloys. [Extracted from the article]

Zr-containing rare earth magnesium alloys have garnered considerable attention due to their exceptional properties, making them highly desirable for various engineering applications (Chen et al. in Mater Rev 30(9):1–9, 2016). However, flow line defects have been observed to impact the mechanical performance of these alloys, warranting a thorough investigation into their origin and impact. Utilizing advanced analytical techniques, such as scanning electron microscopy and non-destructive testing, we elucidate the microstructural characteristics of these defects and their underlying formation mechanisms by numerical simulation and experiment. Subsequently, the influence of flow line defects on the mechanical properties, such as tensile strength and ductility, is thoroughly assessed. Furthermore, this work outlines practical strategies to mitigate the formation of flow line defects during processing and fabrication, thereby enhancing the overall mechanical integrity of Zr-containing rare earth magnesium alloys. This research contributes valuable insights to the field of advanced magnesium alloys, offering guidelines for engineering design and industrial implementation. [ABSTRACT FROM AUTHOR]

In order to study the effects of REs (Ce, Y and Gd) on the grain size and the grain refinement mechanism of AZ91 as-cast magnesium alloy at different cooling rates, the AZ91-xRE(Ce, Y, Gd, x = 0, 0.3, 0.6, 0.9) alloys with different cooling rates were prepared by die casting. The results show that the addition of REs to AZ91 magnesium alloy and the increase in cooling rate both can refine the grain size of the alloy, but the grain refinement effects of REs on AZ91 magnesium alloy will be weakened when the alloy is solidified at a faster cooling rate. The grain refinement effects of REs on AZ91 magnesium alloy are mainly due to the rare earth compounds of Al4Ce, Al2Y and Al2Gd which can act as heterogeneous nucleation particle to promote nucleation and the inhibitory effects of rare earth compounds distributed near grain boundaries on the grain growth. Increasing the cooling rate of the alloy will reduce the effective constitutional supercooling zone and increase the proportion of nucleation-free zone, which will weaken the heterogeneous nucleation particle effect of Al4Ce, Al2Y and Al2Gd, thereby weakening the grain refinement effects of REs on the AZ91 magnesium alloy at a faster cooling rate. [ABSTRACT FROM AUTHOR]

In this study, pure and hexagonal boron nitride (hBN)-doped zinc oxide (ZnO) nanoparticles with different doping ratios (1, 5 and 10 wt%) were synthesized and their structural morphological properties were investigated. ZnO-hBN nanocomposite particles were used as reinforcement material in AZ91 magnesium alloy. AZ91 powder reinforced with ZnO-hBN nanocomposite particles was combined by powder metallurgy. Hardness of AZ91 matrix composites was measured at 5 different points on each sample and averaged. The specimens were subjected to wear tests in a pin-on-disk test apparatus. As a result of the tests, the hardness value of pure AZ91 alloy was found to be 62 HB, while the hardness value of AZ91-ZnO-10 hBN sample was found to be up to 85 HB. In the wear tests, it was observed that ZnO-hBN additives resulted in low weight losses in wear losses and also decreased the friction coefficient of the hBN additive in the friction coefficient graphs. A hybrid GA (genetic algorithm)-SVR (support vector regression) model was proposed for the prediction of wear quantities of composites. The purpose of using a hybrid system combining SVR and GA is to improve the wear prediction by optimizing the hyperparameters of t and GA. The results are observed using four different kernel functions in the SVR algorithm, and then, a hybrid GA-SVR structure is proposed and compared. With the proposed method, 98.80% prediction success of the wear quantities of the composite is achieved by the hybridized GA. [ABSTRACT FROM AUTHOR]

Niobium (Nb) and zirconium dioxide (ZrO2) were doped into hydroxyapatite (HA) to fabricate HA-based composite coatings prepared on a ZK60 magnesium alloy by plasma spraying technology to improve anti-corrosion and biocompatibility for clinical applications. The results revealed that the Nb-enriched coating exhibits fewer cracks and pores with a flat surface due to the decreased temperature gradient during spraying, and small needle-like structures can fill the cracks and pores in the ZrO2-contained coating, resulting in a more uniform and dense surface. Compared to coatings with only niobium or zirconium dioxide, the ZrO2/Nb/HA composite coating significantly enhanced the mechanical properties and corrosion resistance of the magnesium alloys. Among all the specimens, the ZrO2/HA coating and ZrO2/Nb/HA coating revealed high surface hardness values (327.73 HV and 293.80 HV, respectively). However, the higher hardness value made the ZrO2/HA coating fragile and more likely to crack, while the ZrO2/Nb/HA coating avoided this shortcoming and exhibited a more comprehensive performance. During immersion tests, the ZrO2/Nb/HA coating exhibited a gradual pH increase and minimal mass loss, and the cytocompatibility test demonstrated promising cellular activity. [ABSTRACT FROM AUTHOR]

This research presents the development of a surface treatment for AZ91D magnesium alloy that exhibits both superhydrophobic and anticorrosive properties. Initially, a zinc-based phosphate film was deposited on the magnesium alloy surface. Subsequently, a composite coating with superhydrophobic properties was produced by surface modification using a fluorosilane-ethanol solution. The composite coating's microstructure, chemical composition, wettability, self-cleaning, and anti-corrosion properties were evaluated using scanning electron microscopy, a contact angle measurement instrument, and an electrochemical workstation. The results demonstrated that the main components of the composite coating were P, O, Zn, F, and C. The static contact angle reached 158°, providing superior self-cleaning and acid and alkali corrosion resistance. Additionally, the charge transfer resistance and coating resistance of the composite coating were significantly higher than those of the magnesium alloy substrate, effectively preventing corrosion and preserving the surface from fouling. [ABSTRACT FROM AUTHOR]

High thermal conductivity ternary Mg alloys composed of Zn and Y pair with a negatively large mixing enthalpy was developed by optimization of alloy composition and heat-treatment conditions. Optimal alloy composition was Mg-1.88Zn-0.75Y (at%) alloy, in which the ratio of Zn content to Y content was 2.5 and the Y content was 0.75 at%. The alloy was composed of a-Mg+W phase (Mg3Zn3Y2)+I phase (icosahedral Mg3Zn6Y). Heat treatment under the optimal heat treatment conditions, where temperature, time and cooling rate were 633 K, 15 h and air cooling, respectively, improved the thermal conductivity from 114 to 141Wm-1K-1 that corresponds to 90% of the pure Mg thermal conductivity. Fine W phase precipitation in α-Mg matrix by the heat-treatment caused a reduction of solute Yelement in α-Mg matrix, resulting in improvement of the thermal conductivity. [ABSTRACT FROM AUTHOR]

Exploring the effect of the magnesium alloy aging process on dynamic impact performance could plays an important role in the application of magnesium alloy in automotive lightweighting. In this work, the effects of single-stage, two-stage, and reverse two-stage aging processes on the dynamic mechanical properties of Mg-8.5 Gd-3 Y-0.5 Zr alloy were studied by means of SEM analysis, hardness testing, a quasi-static compression experiment, and SHPB. The results show that the compressive strength of the materials after single-stage, two-stage, and reverse two-stage aging treatments is improved to different degrees compared with that of the alloys in the extruded state. Due to the generation of dynamic precipitation with semi-annular distribution during SHPB, the compressive strength of the reverse two-stage aging alloys reached an excellent 761 MPa, while the two-stage aging alloys had more dynamic precipitation phases at the strain rate of 3500 s−1, resulting in a compressive strength of 730 MPa, which is superior to that of the aluminum alloys used in a wide range of automotive applications. The results of this study can provide a reference for the application of Mg-Gd magnesium alloys under dynamic loading. [ABSTRACT FROM AUTHOR]

This study examines the dry milling process of a rare-earth-based magnesium alloy, emphasizing the optimization of the milling parameters and their impact on the surface quality, cutting forces, and the rate of material removal. The objective is to improve our comprehension of the milling behavior of the Mg-Gd-Y-Er alloy. The Taguchi technique is adopted to formulate the experimental design. This study methodically investigates the influence of heat treatment (T4 and T6) on milling performance, and the effects of speed, feed rate, and depth of cut. The output variables considered for this investigation are the surface roughness (Ra, Rz, Sa, and Sz), material removal rate (MRR), and cutting force. To optimize the milling parameters and achieve superior outcomes, the multi-objective optimization technique TOPSIS is used. At a feed rate of 150 mm/min, a spindle speed of 1500 rpm, and a depth of cut of 1 mm, the T4-treated sample exhibits a minimum surface roughness value of 0.0305 µm. The highest resultant force values of 96.4416 N and 176.1070 N for 200 °C and 225 °C T6-treated alloys are obtained by combining process parameters such as a spindle speed of 1500 rpm, a feed rate of 50 mm/min, and a depth of cut of 1.5 mm. Furthermore, the maximum closeness coefficient value is achieved by combining a spindle speed of 1000 to 1500 rpm, a feed rate of 150 mm/min, and a depth of cut of 0.5 mm to 1 mm. The closeness coefficient value is significantly influenced by the most significant process parameters, as indicated by the ANOVA results. [ABSTRACT FROM AUTHOR]

In this work, AZ31 and AZ31-1 wt.% RE (RE = Nd, Dy, Nd+Dy) alloys were prepared by conventional casting. The effect of single and co-addition of rare earth (RE) on the microstructure, mechanical properties and corrosion behavior of as-cast AZ31 magnesium alloys were investigated at ambient temperature, and after heat treatment at 400 °C for 1 h. The addition of 1 wt.% RE (RE = Nd, Dy, Nd+Dy) preferentially formed the Al2RE phase and completely suppressed the formation of the intermetallic β-Mg17Al12 phase. An excellent ultimate tensile strength (UTS)/ductility combination of 209 MPa/21% and 192 MPa/17% with an adequate yield strength (YS) of 90 MPa was observed for AZ31+Nd sample in as-cast and annealed states, respectively. The work-hardening rate of the AZ31 alloy containing Nd and Dy increased significantly after annealing compared to those of the as-cast state. Fracture analysis indicated that the additive RE did not obviously change the fracture mechanism of the Mg alloy. All specimens exhibit a hybrid fracture with cleavages and dimples. The weight loss test showed that the corrosion resistance of the AZ31 Mg alloy was improved with added RE as it interacts with Al to form Al-RE phase, which upgraded the corrosion resistance of the alloys. The co-addition of RE (RE = Nd+Dy) was proven to enhance corrosion resistance, and also stabilized the corrosion rate. In brief, the co-addition of Nd and Dy significantly improved the corrosion resistance of the AZ31 magnesium alloys than the counterpart of the mechanical properties. [ABSTRACT FROM AUTHOR]

The demands of next-generation transportation such as electric and hybrid vehicles as well as computing and renewable energy applications require new alloys with high castability, high electrical and thermal conductivity, and moderate strength. Aluminum and Mg alloys offer respectable electrical and thermal conductivity with high specific properties unlike Cu and precious metals. However, traditional light alloy systems rely on significant alloying content for solid solution strengthening and to generate short freezing ranges for high castability that is associated with a large decrease to electrical and thermal conductivity. Aluminum alloys based on transition metal and rare earth additions (Fe, Ni, Co and Ce) as well as Mg alloys with additions of Zn, Ca and Ce are potential highly castable alloys with high electrical and thermal conductivity. These new conductive light alloys rely on alloy additions that have low solid solubility but provide short freezing ranges. Results indicate that these Al and Mg alloys can have electrical conductivities ~ 80% of their pure counterparts and castability similar to traditional cast Al–Si and Mg–Al alloys. [ABSTRACT FROM AUTHOR]

A high strength and toughness AZ63 cast magnesium alloy whose ultimate tensile strength, yield strength and elongation at room temperature respectively reached 319 MPa, 160 MPa and 7.6%, was developed by combining the alternating-temperature ultrasonic melt treatment and T6 heat treatment. The high as-aged tensile properties of the alloy with the alternating-temperature ultrasonic melt treatment are mainly attributed to the remarkable increase of the β-prismatic precipitates with orientation relationships (ORs) of ( $ \bar{3}\bar{3} $ 3 ¯ 3 ¯ 0)β // (1 $ \bar{1} $ 1 ¯ 00)α, [ $ \bar{1} $ 1 ¯ 11]β // [11 $ \bar{2} $ 2 ¯ 0]α, thereinto the mentioned-increase is possibly related to that the solute-vacancy clusters along {0 $ \bar{1} $ 1 ¯ 11} plane might serve as the nucleation points of the β-prismatic precipitates. [ABSTRACT FROM AUTHOR]

The performance of aluminum alloys can be affected by the element of magnesium. Therefore, it is necessary to realize fast and accurate quantitative analysis of magnesium in aluminum alloys. Herein, high repetition rate spark discharge assisted laser-induced breakdown spectroscopy based on microchip lasers (HRR SD-LIBS) was applied to quantitatively analyze magnesium elements in aluminum alloys. Baseline correction was performed using the moving median method to obtain the net spectral data. Multivariate calibration models such as back-propagation neural network (BP), support vector machine (SVM), and random forest (RF) were established, respectively. Compared with the conventional univariate calibration model, the correlation coefficients (RP²) of BP,SVM and RF models increased from 0. 810 to 0.985, 0.997 and 0.994, while the root mean square error (RMSEP) decreased from 0.283 to 0.059 8, 0.041 0 and 0.054 2, the average relative error decreased from 26.62% to 3.13%, 2.82%, and 3.61%. It indicated that machine earning combined microchip laser-based HRR SD-LIBS significantly improved the quantitative analysis ability of LIBS. In conclusion, it is promising to achieve portable, fast, and accurate quantitative elemental analysis of alloy sample and other materials. [ABSTRACT FROM AUTHOR]

In view of the importance of metal coatings, this study addresses the ion concentration of the anti‐corrosive coating's immersion solution. The physical properties of the coating surface, such as molecular characteristics, smoothness, and structural strength, were changed by adding nano‐SiO2 in the immersion solution to formulate the best scheme for anti‐corrosive performance. The composite coating was prepared on the surface of AZ31B magnesium alloy by electroless plating. Besides, the surface coating based on AZ31B substrate has high‐quality corrosion resistance to different types of contaminated media. The experimental results demonstrate that the nanocomposite coating can form an ultrafine particle‐filling effect on the metal surface, which is lower than the drag force of the conventional metal surface. Considering the slip velocity gradient in the contact coating area, we reduce the shear stress and drag force, verifying the nanocomposite coating's effect on reducing the reaction force. The contact angle of water droplets in the composite coating is greater than 158.7°. The study finally verifies that the prepared coating has good self‐cleaning potential which can prevent the corrosion of different polluted media. [ABSTRACT FROM AUTHOR]

Magnesium (Mg) and its alloys have received much attention in the aerospace, transportation, automotive industry, and military equipment fields due to their unique chemical and physical properties, such as their low density and high specific strength, particularly as the lightest structural metal materials, with the opportunity to achieve the design of lighter engineering systems. With the continuous improvement of processing technology, the application scope of magnesium alloy is rapidly expanding, and market demand is increasing. However, because of its significant electronegativity (2.37 V) and loose naturally formed oxide coating, magnesium has low corrosion resistance in comparison to other structural metal elements, severely limiting its large‐scale use. This review summarizes several typical anticorrosion methods for magnesium alloys, including chemical conversion coating treatment, anodic oxide film treatment, micro‐arc oxidation treatment, laser surface treatment, ion implantation, physical vapor deposition, and superhydrophobic coating. In most cases, the corrosion resistance of magnesium and its alloys has improved, but it has a certain degree of environmental damage. It is hoped that this review will contribute to further developing magnesium alloy materials in the field of preservative coating. [ABSTRACT FROM AUTHOR]

Magnesium alloys have a huge market and broad prospects due to their high specific strength, good ductility, and strong thermal conductivity. However, the active chemical properties of elemental magnesium and the negative standard electrode potential result in magnesium alloys being highly susceptible to corrosion and failure. Chemical conversion treatment of magnesium alloy can improve its corrosion resistance by preparing a chemical conversion film on its surface. Rare earth conversion treatment has the advantages of effortless process, moderate price, no pollution, good corrosion resistance, and synergistic effect with inorganic or organic additives, which is in line with the pursuit of “green chemical” in industrial production. At present, there is little research and application on lanthanum-based rare earth conversion coatings (La-RECC). This paper selects rare earth element lanthanum (La) to prepare La-RECC on the surface of AZ91D magnesium alloy through chemical conversion treatment. The microstructure, chemical composition, and protective properties of La-RECC were discovered, as well as their interrelationships, revealing the degradation process of La-RECC in 3.5% NaCl solution. La-RECC is composed of La(OH)3 and Mg(OH)2, exhibiting a crystal cluster structure with cracks, and there are a large number of needle-like crystals on the crystal cluster of La-RECC, with a thickness of 2.14 μm. The degradation process of La-RECC can be divided into three stages: Rapid degradation, slow degradation, and complete degradation. The complete degradation time of La-RECC in 3.5% NaCl solution is 82.5h. [ABSTRACT FROM AUTHOR]

“Anodeless” electrodes for all‐solid‐state batteries (ASSBs) have been attracting attention as a solution for achieving high energy density. Recent studies on anodeless electrodes have shown improvements in cycle life and energy density through the stabilization of plated lithium (Li) using Li‐soluble metals (e.g., Ag, Zn, etc.). In this study, magnesium‐based materials (MgF2@C) are introduced for use as an anodeless electrode. Nanodot magnesium fluoride (MgF2) is synthesized onto a carbon black surface via sonochemical synthesis. MgF2 is converted to a Mg‐Li alloy and LiF during lithiation. The Mg‐Li alloy from the MgF2@C anodeless electrode reduces lithiation overpotential and provides a uniform and dense Li layer between the current collector and the anodeless electrode. The ASSB cell assembled with the MgF2@C anodeless electrode exhibits 81.4% capacity retention after 200 cycles at 30 °C. [ABSTRACT FROM AUTHOR]

The formation of intermetallic compounds (IMCs) is a primary factor that affects the welding joint between dissimilar materials. In this study, experiments were performed using Al/Mg friction stir welding (FSW) and ultrasonic vibration enhanced FSW (UVeFSW) with varying thicknesses of Sn interlayer. Detailed characterization and tests were conducted to explore the effect of Sn interlayer with or without ultrasonic vibration on weld surface morphology, macro-micro structure, generation of IMCs, and joint tensile strength. The study discusses the effect of ultrasonic vibration coupled with Sn interlayer and provides ideas for IMCs regulation when joining dissimilar materials. The study showed that adding a Sn interlayer cannot eliminate the generation of Al-Mg IMCs, but it can significantly reduce their thickness. Applying ultrasonic vibration with Sn interlayer can further reduce the thickness of Al-Mg IMCs and improve the interface microstructure from 'IMC + matrix +IMC + matrix' multilayer structures to simple IMCs structures. Furthermore, the highest joint strength was achieved when the Sn interlayer thickness was 0.1 mm during FSW. UVeFSW's joint strength can be further improved with 0.05 mm and 0.1 mm Sn interlayer. [ABSTRACT FROM AUTHOR]

Within the scope of these investigations, the feasibility of a material bond between Ti-6Al-4V and the magnesium alloy AZ91 is analyzed. Ti-6Al-4V is frequently used for implants due to its biocompatibility, corrosion resistance, and specific strength. However, depending on the surface quality, the attachment behavior of the bone to the implant varies. Magnesium implants promote the regeneration of bone tissue and biodegrade as the bone tissue heals. Combining the properties of both materials in one implant enables a reduced implant volume and increased stability. For this reason, this study aims to demonstrate the feasibility of creating a material bond between the materials Ti-6Al-4V and AZ91. For this purpose, Ti-6Al-4V truncated cones and AZ91 sleeves were produced using the additive manufacturing process of laser powder bed fusion (L-PBF). The as-built sleeves were then pressed onto machined truncated cones. Since zinc serves as a lubricant and has good diffusion properties with the materials used as a result of heat treatment, a comparison was made between zinc-coated and the as-built Ti-6Al-4V samples. This showed that a bond was created after hot isostatic pressing and that the push-out force could be increased by more than 4.5 times. Consequently, a proof of feasibility was demonstrated, and a high potential for applications in medical technology was shown. [ABSTRACT FROM AUTHOR]

The synergic effects of activated carbon and transition metals on the hydrogenation characteristics of commercial ZK60 magnesium alloy were investigated. Severe plastic deformation was performed using equal-channel angular pressing with an internal die angle of 120° and preheating at 300 °C. The ZK60 alloy samples were processed for 12 passes using route BA. The deformed ZK60 alloy powder was blended with activated carbon and different concentrations of transition metals (Ag, Pd, Co, Ti, V, Ti) using high-energy ball milling for 20 h at a speed of 1725 rpm. The amount of hydrogen absorbed and its kinetics were calculated using Sievert's apparatus at the higher number of cycles at a 300 °C ab/desorption temperature. The microstructure of the powder was analyzed using an X-ray diffractometer and scanning electron microscope. The results indicated that 5 wt% activated carbon presented the maximum hydrogen absorption capacity of 6.2 wt%. The optimal hydrogen absorption capacities were 7.1 wt%, 6.8 wt%, 6.7 wt%, 6.64 wt%, 6.65 wt%, and 7.06 wt% for 0.5 Ag, 0.3 Co, 0.1 Al, 0.5 Pd, 2 Ti, and 0.5 V, respectively. The hydrogen absorption capacities were reduced by 35.21%, 26.47%, 41.79%, 21.68%, 26.31%, and 26.34% after 100 cycles for 5C0.5Ag, 5C0.3Co, 5C0.1Al, 5C0.5Pd, 2Ti, and 5C0.5V, respectively. Hydrogen absorption kinetics were significantly improved so that more than 90% of hydrogen was absorbed within five minutes. [ABSTRACT FROM AUTHOR]

The AZ91 magnesium alloy was subjected to a complex treatment involving age hardening (supersaturation and artificial aging) and simultaneous surface layer modification. The specimens were supersaturated in contact with a mixture containing varying concentrations of zinc chloride, followed by cooling either in air or water. After supersaturation, the specimens were subjected to artificial aging and then air-cooled. This process resulted in the formation of a surface layer made of zinc-rich phases. The thickness and microstructure of the surface layer were influenced by the process parameters, namely, the zinc chloride content in the mixture and the cooling rate during supersaturation. The treated specimens exhibited favorable tensile strength and greater elongation compared to the as-cast AZ91 alloy, with values comparable to those of the alloy subjected to standard T6 tempering. No cracking of the layer was observed under moderate deformation, though greater deformation resulted in the formation of cracks, primarily in the areas containing the Mg5Al2Zn2 intermetallic phase. The produced layer demonstrated strong metallurgical bonding to the AZ91 substrate. [ABSTRACT FROM AUTHOR]

Excessive cooling of air is required in conventional air conditioning systems to reduce the humidity, leading to the development of desiccant wheel-based air conditioning systems. The desiccant wheel consists of desiccant material which is deposited on matrix material. In this study, aluminum, magnesium alloy, Teflon, and fiberglass have been considered matrix materials of the desiccant wheel. A one-dimensional mathematical model has been developed to evaluate the effect of these matrix materials. The results show that fiberglass can be selected as a suitable matrix material for drying applications because it has maximum moisture removal (MR; 1.92 g/kg) and temperature difference (4.72 °C) at optimal rotational speed, which are desirable for drying. While aluminum can be selected as a suitable matrix material for air conditioning applications because, at the optimal rotational speed, it has lower maximum MR (1.26 g/kg) and temperature difference (3.14 °C) as compared to other matrix materials. As moderate maximum MR and lower temperature difference are the requirements for air conditioning. A similar trend of results has been also obtained for other parameters (volume ratio, regeneration velocity, regeneration temperature, etc.) of this study. [ABSTRACT FROM AUTHOR]

Europium-hydroxyapatite (Eu-HA) nanocomposite was developed via continuous hydrothermal synthesis. Eu+3 ions partially replaced the Ca+2 ions within hydroxyapatite molecular structure. High quality Eu-HA nanorods of 20 nm width and 6 μm lengths were verified via TEM micrographs. Eu-HA maintained the crystalline structure of HA with minimum change; material studio software confirmed the partial replacement of Ca+2 by Eu+3. XPS analysis demonstrated Eu+3 content of 6.91 atom %. Ca/P ratio was found to be 1.405 and 0.118 for virgin HA and Eu-HA respectively; this was ascribed to the partial replacement of Ca+2 with Eu +3. The EDAX mapping verified the uniform dispersion of Eu ions within Eu-HA structure. Eu-HA nanocomposite was uniformly distributed in silica sol-gel matrix; subsequently it was applied on AZ31 magnesium alloy. The corrosion performance of Eu-HA sol-gel coating nanocomposite (Eu–S) was evaluated using different electrochemical techniques including Potentiodynamic Polarization (PDP), Electrochemical Impedance Spectroscope (EIS), and Electrochemical Noise (EN) in aerated 0.1 M NaCl solution. Corrosion protection was assessed to that of neat silica sol-gel coating (NSG). Pitting was detected over the whole NSG coated sample, after few hours of immersion in the corrosive solution. EuS coated AZ31 withstand up to 144 h without any sign of corrosion or delamination. EIS analysis with PDP parameters suggested the formation of protective layer; that is responsible for the corrosion resistance. Europium has unique ability to form a protective oxide layer acting as a barrier layer that could prevent the penetration of corrosive electrolyte to the underlying metal substrate. [ABSTRACT FROM AUTHOR]

To reveal the influences of solution temperature and Nd addition on microstructures and mechanical properties of Mg-12Gd-2Zn-xNd-0.4Zr (x = 0, 0.5, and 1 wt.%) alloys, optical microscope, scanning electron microscope, tensile testing machine, nano-indentation tester, and Vickers hardness tester were used to study the microstructures and mechanical properties of the solution-treated alloys. The results show that with the increase in solution temperature, the alternating α-Mg and β-(Mg, Zn)3Gd eutectic phase and the stacking faults (SFs) and long-period stacking ordered (LPSO) structures gradually decrease and disappear, accompanied by the increased needle-like precipitated phase. The β-(Mg, Zn)3Gd and needle-like precipitated phases increase with increasing Nd addition under the same solution temperature. The yield strength and elongation are both enhanced with increasing solution temperature, the yield strength is also improved but the elongation is reduced with increasing Nd addition. Most importantly, the comprehensive mechanical property, called product of strength and elongation, is significantly improved by increasing solution temperature for the three alloys, but overall, it is reduced with increasing Nd addition solution treated at the same temperature. The Mg-12Gd-2Zn-0.5Nd-0.4Zr solution treated at 515 °C shows the highest product of strength and elongation (4498.4 MPa%) with the ultimate tensile strength of 335.7 MPa and elongation of 13.4%. [ABSTRACT FROM AUTHOR]

Magnesium alloys are widely used for orthopedic implants due to their biocompatibility and biodegradability. However, their low corrosion resistance limits their application, particularly in physiological environments. The goal of this study is to examine how a three-layer coating, consisting of MOF/3D rGO/PCL, affects the corrosion resistance and in vitro biocompatibility of a biodegradable Mg–Mn–Zn alloy in a simulated body fluid (SBF). Corrosion behavior was evaluated using potentiodynamic polarization and electrochemical impedance spectroscopy. The results demonstrate a significant enhancement in the corrosion resistance of the modified alloy. Additionally, cell culture experiments were conducted to investigate the biocompatibility of the coatings. The data from the methylthiazole tetrazolium (MTT) and alkaline phosphatase (ALP) bioassays indicate a substantial improvement in the growth process of MC3T3-E1 osteoblastic cells and an increase in ALP activity in SBF. This confirms the non-toxicity and biocompatibility of the synthesized coating in the SBF solution. The findings of this study will be valuable for the development of biodegradable materials in biomedical applications. [ABSTRACT FROM AUTHOR]

The commercialization of magnesia–air batteries (Mg–air) necessitates the development of highly efficient, cost-effective, and durable electrocatalysts for the oxygen reduction reaction (ORR), replacing expensive and unstable precious metal electrocatalysts. A hard template-assisted synthesis of FeCo nanoparticles immobilized on N-doped porous carbon (Fe–Co–C–N) for the ORR is reported. The half-wave potential of Fe–Co–C–N for ORR (E1/2 = 0.88 V vs. RHE) is elevated by 40 mV compared to that of 20 wt% Pt/C (E1/2 = 0.84 vs. RHE). The catalyst exhibits exceptional catalytic performance and remarkable stability. The discharge voltage of the Mg–air battery, utilizing Fe–Co–C–N as the cathode catalyst (1.29 V), surpasses that of the battery employing 20 wt% Pt/C as the cathode catalyst (1.28 V). The Mg–air battery with Fe–Co–C–N as the cathode catalyst exhibited excellent discharge stability and maintained a stable discharge for over 200 hours. The present study offers valuable insights into the structural design and regulatory mechanisms governing the performance of M–N–C catalysts in Mg–air batteries. [ABSTRACT FROM AUTHOR]

Porous hexagonal nanoplatelets of mixed metal oxide (MMO) derived from the calcination of MgAl layered double hydroxide exhibits a CO2 sorption capacity of 1.99 mmol g−1 at 30 °C, with a retention of 87% sorption capacity over 10 carbonation–decarbonation cycles and a CO2 sorption capacity of 1 mmol g−1 at 200 °C with a 40% increase in capacity over 10 cycles. The high sorption capacity is attributed to the porous nanoplatelet structure of the MMO with a BET surface area of 115 m2 g−1, which enables increased CO2 diffusion. Upon partially replacing magnesium with calcium (33, 50 and 66 mol%), the CO2 sorption capacity of the MMO increases with an increase in temperature. MMO derived from LDH, in which 66% of magnesium is replaced by calcium (MgCaAl-66), delivers CO2 sorption capacities of 1.38, 1.31, 2.50, 4.85 and 7.75 mmol g−1 at 200, 300, 350, 400 and 600 °C, respectively, which is significant for application in the sorption-enhanced water gas shift (SEWGS) process. MgCaAl-66 MMO exhibits a sorption capacity of 1 mmol g−1, which is stable over 10 cycles at 200 °C, and a sorption capacity of 3.68 mmol g−1 at 400 °C with 85% capture efficiency retention over 10 cycles. While the incorporation of Ca2+ serves multiple purposes such as increasing basic defect sorption sites and improving stability to repress the sintering-induced limitation of MMO over sorption cycles, the porous nanoplatelets act as individual sorbent units resisting volume changes through carbonation–decarbonation cycles. [ABSTRACT FROM AUTHOR]

Magnesium borate whiskers were used to prepare a hierarchical microstructure on cordierite ceramic substrate through the precipitation-molten salt method. The La 2-X Ce X Zr 2 O 7 catalyst was then loaded onto the magnesium borate whiskers to form the hierarchical microstructure. The Ce-doped catalysts exhibited a significant improvement in the catalytic activity of soot combustion compared to the La 2 Zr 2 O 7 catalyst. The study employed various techniques to characterize the structural morphology and phase composition, including scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), Fourier transform-infrared spectroscopy (FT-IR), and X-ray diffraction (XRD). The growth of Magnesium borate whiskers (Mg 2 B 2 O 5) with diameters of 100–200 nm and lengths of 2–5 μm were grown and tightly bonded to the cordierite ceramic substrate to mimic the structure of human respiratory system cilia. This could improve the filtration efficiency of soot in car exhaust. BET analysis showed that the specific surface area of cordierite increased from 0.684 m2/g to 1.363 m2/g after whisker growth. The study confirmed that the whiskers were firmly attached to the cordierite ceramic substrate, as demonstrated by the binding strength experiments. The addition of Ce metal has been found to significantly enhance soot combustion due to the presence of more active oxygen species and superior mobility of lattice oxygen species with more oxygen vacancies. The catalyst's intrinsic redox property was characterized using X-ray photoelectron spectroscopy (XPS) and H 2 temperature-programmed reduction (H 2 -TPR). The semi-quantitative thermogravimetric analysis (TG-DTG) and the temperature-programmed oxidation (TPO) of catalysts showed that Z-La 1.9 Ce 0 · 1 Zr 2 O 7 exhibited the highest catalytic activity for soot combustion, with an ignition temperature of 268 °C, a peak temperature of 418 °C, and a temperature of 90 % soot conversion of 464 °C. Furthermore, cyclic stability experiments demonstrate that the Z-La 1.9 Ce 0 · 1 Zr 2 O 7 catalyst exhibits excellent structural stability and consistent catalytic performance. This distinctive microstructure holds great potential for applications in the field of DPF. [ABSTRACT FROM AUTHOR]

Aluminum and magnesium are the lightest structural metals, and therefore, various alloys based on them are widely used in both, automotive and aerospace industries. However, aluminum and magnesium are very easily affected by atmospheric and aqueous corrosion, and, therefore, the alloying elements should enhance their corrosion stability. In this work, the thermodynamic analysis of phase and chemical equilibria involving aluminum and magnesium alloys doped with silicon in oxygen–containing air environments, as well as the analysis of chemical and electrochemical equilibria involving these alloys in aqueous environments is conducted. The phase and chemical equiliibria in the Al–Mg, Al–Si, Mg–Si, and Al–Mg–Si systems at 298 K are considered, and the thermodynamic activities of the components of common Al–Mg–Si system alloys are calculated. The invariant chemical equilibria in the systems Al–Mg–O, Al–Si–O, Mg–Si–O at 298 K are considered, the isothermal section of the state diagrams of these systems are plotted, and the oxidation scheme of the Al–Mg–Si system alloys in excess oxygen is proposed. The chemical and electrochemical equilibria in the Al–Mg–Si–H2O system at 298 K are considered and presented in form of the activity – pH and the potential – pH diagrams, and the oxidation of the Al–Mg–Si system alloys in aqueous environments is discussed. [ABSTRACT FROM AUTHOR]

Traditional chemotherapy drugs for cervical cancer often cause significant toxic side effects and drug resistance problems, highlighting the urgent need for more innovative and effective treatment strategies. Magnesium alloy is known to be degradable and biocompatible. The release of degradation products Mg2+, OH−, and H2 from magnesium alloy can alter the tumor microenvironment, providing potential anti-tumor properties. We explored the innovative use of magnesium alloy biomaterials in the treatment of cervical cancer, investigating how various concentrations of Mg2+ on the proliferation and cell death of cervical cancer cells. The results revealed that varying concentrations of Mg2+ significantly inhibited cervical cancer by arresting the cell cycle in the G0/G1 phase and inducing apoptosis in SiHa cells, effectively reducing tumor cell proliferation. In vivo experiments demonstrated that 20 mM Mg2+ group had the smallest tumor volume, exhibiting a potent inhibitory effect on the biological characteristics of cervical cancer. This enhances the therapeutic potential of this biomaterial as a local anti-tumor therapy and lays a theoretical foundation for the potential application of magnesium in the treatment of cervical cancer. [ABSTRACT FROM AUTHOR]

An investigation has been performed to study the compatibility of machining AZ91 magnesium alloy in dry conditions using uncoated and CVD diamond-coated WC-Co inserts. The machining characteristics such as built-up edge (BUE) formation, surface roughness, cutting forces and chip morphology were studied at the cutting speeds, 350, 650 and 950 m/min. The results revealed severe adhesion of the AZ91 Mg alloy on the uncoated WC-Co inserts with increasing cutting speed and contributed to an increase in surface roughness and cutting forces. The CVD diamond-coated inserts have shown negligible built-up edges at various cutting speeds due to their unique properties like low coefficient of friction, low chemical affinity and high thermal conductivity. Snarled types of long continuous chips were observed while machining with CVD diamond-coated WC-Co inserts, whereas short continuous chips were observed with uncoated WC-Co inserts. [ABSTRACT FROM AUTHOR]

Segregation is a serious defect in alloy ingots which severely deteriorates materials performance. The segregation defect in Mg-6Gd alloy is studied by coupling macro thermal-solutal-convection transport and micro dendrite growth. The macroscopic fluid dynamics and mass transfer equations are resolved to forecast the segregation behavior under conditions of continuous temperature variation during the solidification process. The numerical model is validated by testing double-diffusive natural convection in a closed square cavity. A phase field model is then applied to simulate the micro dendrite growth, using macro undercooling and liquid flow velocity as boundary conditions. Results show that the multiscale segregation behavior, including macro solute distribution and micro dendritic morphology, is strongly dependent on the temperature condition and the liquid convection, which provides guidance for reducing and eliminating the segregation defect. [ABSTRACT FROM AUTHOR]

In order to effectively reduce energy consumption and increase range mile, new energy vehicles represented by Tesla have greatly aroused the application of integrated magnesium (Mg) alloy die casting technology in automobiles. Previously, the application of Mg alloys in automobiles, especially in automotive cockpit components, is quite extensive, while it has almost disappeared for a period of time due to its relatively high cost, causing a certain degree of information loss in the application technology of Mg alloy parts in automobiles. The rapid development of automotive technology has led to a higher requirement for the automotive components compared with those traditional one. Therefore, whatever the components themselves, or the Mg alloy materials and die casting process have to face an increasing challenge, needing to be upgraded. In addition, owing to its high integration characteristics, the application of Mg alloy die casting technology in large-sized and thin-walled automotive parts has inherent advantages and needs to be expanded urgently. Indeed, it necessitates exploring advance Mg alloys and new product structures and optimizing die casting processes. This article summarizes and analyzes the development status of thin-walled and large-sized die casting Mg alloy parts in passenger car cockpit and corresponding material selection methods, die casting processes as well as mold design techniques. Furthermore, this work will aid researchers in establishing a comprehensive understanding of the manufacture of thin-walled and large-sized die casting Mg alloy parts in automobile cockpit. It will also assist them in developing new Mg alloys with improved comprehensive performance and new processes to meet the high requirements for die casting automotive components. [ABSTRACT FROM AUTHOR]

High-performance magnesium alloys are moving towards a trend of being produced on a large scale and in an integrated manner. The foundational key to their successful production is the high-quality cast ingots. Magnesium alloys produced through the conventional semi-continuous casting process inevitably contain casting defects, which makes it challenging to manufacture high-quality ingots. The integration of external field assisted controlled solidification technology, which combines physical fields such as electromagnetic and ultrasonic fields with traditional semi-continuous casting processes, enables the production of high-quality magnesium alloy ingots characterized by a homogeneous microstructure and absence of cracks. This article mainly summarizes the technical principles of those external field assisted casting process. The focus is on elaborating the refinement mechanism of different types of electromagnetic fields, ultrasonic fields, and combined physical fields during the solidification of magnesium alloys. Finally, the development prospects of producing highquality magnesium alloy ingots through semi-continuous casting under the external field were discussed. [ABSTRACT FROM AUTHOR]

The fabrication of dissimilar metal joints, particularly between AA 6061 aluminum alloy (Al) and AZ31B magnesium alloy (Mg), poses significant technical challenges due to their distinct metallurgical characteristics and the inherent difficulties associated with welding such materials. These challenges include the propensity for intermetallic compound formation, thermal cracking, and differences in thermal and mechanical properties between the two alloys. Cold Metal Transfer (CMT) welding, known for its low heat input and controlled metal transfer, offers a potential solution to these issues. However, optimizing the process parameters to ensure strong, defect-free joints requires a systematic approach. This study aims to optimize CMT welding parameters using parametric mathematical modeling (PMM) to produce high-strength Al and Mg dissimilar joints and to study the effects of CMT parameters on tensile strength (TS) and weld metal hardness (WMH), as well as the microstructural features of AA 6061 aluminum alloy/AZ31B magnesium alloy (Al/Mg) dissimilar joints. Al/Mg dissimilar butt joints were produced by the CMT process using ER4043 as filler wire. CMT, a low-heat input welding technique, was used to mitigate issues such as intermetallic compounds (IMCs), wider heat-affected zone (HAZ), and distortion. The CMT parameters, particularly wire feed speed (WFS), welding speed (WS), and arc length correction (ALC), were optimized using response surface methodology (RSM) to maximize the TS and WMH of the Al/Mg dissimilar joints. Polynomial regression was employed to create PMMs that integrated these CMT parameters to forecast the TS and WMH of the joints. An analysis of variance (ANOVA) was applied to assess the feasibility of the PMMs. The results indicated that the Al/Mg dissimilar joints, produced using a WFS of 4700 mm/min, a WS of 280 mm/min, and an ALC of 10%, exhibited higher TS and WMH values of 33 MPa and 95.8 HV, respectively. The PMMs provided precise forecasts for the TS and WMH of the Al/Mg joints with an error rate of less than 1% and a confidence level of 97%. [ABSTRACT FROM AUTHOR]

The automotive and aerospace sectors are progressively employing the magnesium (Mg) alloy of the grade AZ31B because of its excellent castability, low density, and high ratio of strength to weight. Nevertheless, the limited ability of AZ31B alloy to withstand corrosion limits their use in several fields of technology. In order to solve this problem, the AZ31B alloy is coated utilizing an AA2024/Al2O3 metal matrix composite (MMC) coating that is applied by the cold spray coating (CS) method. The primary goal of this work is the parametric optimization of CS process for maximizing adhesive strength of MMC-coated Mg-alloy substrate. Response surface methodology (RSM) is implemented to find the optimum CS parameters, including feed rate of powder -- FRP (g/min), standoff distance of gun -- SDG (mm) and processing temperature -- TEMP (°C). The regression-based parametric adhesion strength prediction (ASP) model was formulated using the RSM and statistically validated using analysis of variance (ANOVA). Employing 3D surface of responses, the influence of CS parameters on the adhesion strength of an MMC-coating was assessed. The findings revealed that when the MMC-coating was cold sprayed on the Mg-alloy using FRP of 22 g/min, SDG of 12 mm, and TEMP of 520 °C, the maximum adhesion strength of MMC-coating was 70 MPa (actual). Given less than 2% error at 95% confidence, the parametric ASP model correctly predicted the adhesion strength of the MMC-coating. The ANOVA findings showed that FRP (g/min) had significant effect on adhesive strength of MMC-coating followed by SDG (mm) and TEMP (°C). The MMC-coating applied using the RSM optimized CS parameters showed 70.73% superior adhesive strength owing to the lower porosity formation of 2 vol% which offers greater interfacial area. The ASP equation was formulated using the "best fitting line" approach and validated using ANOVA for predicting the adhesive strength (MPa) from the porosity formation (vol%) in the MMC-coating. [ABSTRACT FROM AUTHOR]