Magnesium Matrix Research Articles

Study on the mechanism of magnesium calcium alloys/mineralized collagen composites mediating macrophage polarization to promote bone repair

Magnesium-based composites are a focal point in biomaterials research. However, the rapid degradation rate of magnesium alloys does not align with the healing time of bone tissue. Additionally, the host reaction caused by magnesium implantation hampers its full osteogenic potential. To maintain an appropriate microenvironment, it is important to enhance both corrosion resistance and osteogenic activity of the magnesium matrix. In this study, a composite scaffold composed of mineralized collagen and magnesium alloy was utilized to investigate the regulatory effect of mineralized collagen on mouse macrophages and evaluate its impact on mouse bone marrow mesenchymal stem cells in terms of osteogenesis, immune response, and macrophage-induced osteogenic differentiation. This experiment examined the biocompatibility of mouse bone marrow mesenchymal stem cells and macrophage-induced osteogenic differentiation in vitro, and examined the expression levels of relevant pathways proteins. Magnesium calcium alloys/mineralized collagen exhibited extensive spreading, facilitated by broad and abundant pseudopodia that firmly adhered them to the material surface and promoted growth and pseudopodia formation. The findings revealed that magnesium calcium alloy/mineralized collagen scaffold materials induced osteogenic differentiation mainly through M2 polarization of macrophages. This effect was mainly mediated by promoting the integrin α2β1-FAK-ERK1/2 signaling pathways and inhibiting the RANK signaling pathways.

Research progress on nanoparticles reinforced magnesium alloys

Magnesium alloys, acknowledged as the environmentally-friendly engineering material of the 21st century, are ideally suited to fulfill the requirements of lightweight manufacturing. However, the poor plasticity of magnesium alloys hampers their further application. Subsequently, development of nanoparticle-reinforced magnesium matrix composites has been proven to be a promising way to enhance the comprehensive performance of magnesium alloys. The exceptional performance achieved even by very small number of reinforcements stimulated innovation in preparation techniques and in-depth analysis of reinforcement mechanisms. This paper provides a review on key challenges related to their processing, the profound impact of different micro-nanoparticle reinforcements on the microstructure and properties of magnesium matrix composites during solidification and subsequent deformation machining. Additionally, the reinforcement mechanisms of the excellent mechanical performance of the composites are also discussed. This study can provide valuable insights for the understanding of the selection of appropriate reinforcements and processing to optimize the performance nanoparticle-reinforced magnesium matrix composites.

Investigation on the interface bonding and reinforcement mechanism of nano Ti/AZ31 magnesium matrix composites

In this study, nano Ti/AZ31 composites were successfully prepared by powder metallurgy method, and the strength and plasticity of the composites were improved in both directions. The SEM shows that the Ti particles were evenly distributed at the grain boundary in the sintered composite, and the Ti particles pin the grain boundary to make the grain of the composite significantly refined. EBSD shows that the addition of nano Ti particles significantly reduces the texture strength of the composite and increases the starting probability of the slip system. TEM shows that nano Ti and AZ31 matrix formed stable Al3Ti and MgO phases at the interface, and shows a strong coherent relationship. The nanoindentation test shows that the Ti/AZ31 interface of the composite was stable, the interface bonding energy and interface fracture toughness were gradiently distributed, and the bonding energy and fracture toughness of the interface bonding area were better than those of the matrix. Tensile test shows that the 1.5 wt%Ti/AZ31 composite obtained the best comprehensive mechanical properties with yield strength, ultimate tensile strength and elongation of 143 MPa, 243 MPa and 11.5%, respectively, obviously higher than those of AZ31 alloys. The increased strength was mainly due to the grain refinement and strengthening at grain boundaries. The improved ductility was the result of weakened texture, increase of slip system start-up probability and strong interfacial bonding between Ti particles and AZ31 matrix.

Effect of SiCp on the solidification process of magnesium

In this paper, SiCp was added to the pure Mg matrix by ultrasound-assisted stir casting to prepare SiCp-reinforced magnesium matrix composites. The solidification process and solidification structure were analyzed. The results show that SiCp reacts with a pure magnesium matrix to form the element Si, which affects the nucleation temperature and phase transition time of alloys. The presence of Si element decreases the nucleation temperature of α-Mg. As the SiCp content increases, more Si elements are present, which leads to a lower nucleation temperature of α-Mg. In addition, elemental Si and Mg undergo a eutectic reaction to form Mg2Si, which prolongs the phase transition. Elemental Si also affects the solidification process of Mg. During solidification, the element Si generated by the reaction is enriched at the front of the solid-liquid interface, leading to compositional undercooling, which results in the growth of α-Mg through a non-flat interface. When the α-Mg solidification is complete, a solid solution rich in Si elements is formed. Subsequently, the Si element precipitates from the α-Mg solid solution by secondary crystallization as Mg2Si distributed at grain boundaries and inside the grains.

Review on manufacturability and strengthening mechanisms of particulate reinforced Mg composites

The further development of lightweight and energy-saving engineering materials is a great challenge for scientists in the 21st century. Magnesium and its composites, as the metal materials with the lowest density among metal structural materials, have good thermal conductivity, good dimensional stability, high specific strength, good biocompatibility, which can meet the requirements of energy-saving, emission reduction, environmental protection. In recent years, magnesium and its composites have found the major applications in various fields such as aerospace, automotive industry, electronics and medical industry. However, the fabrication of magnesium matrix composites is difficult, and the deformation behaviors and strengthening mechanisms of particulate reinforced magnesium matrix composites have unique characteristics. This article reviews the recent research progress of the magnesium matrix composites, including different fabrication methods and strengthening mechanisms. According to the classification of solidification rate, the advantages and disadvantages of various techniques used to fabricate magnesium matrix composites were introduced. The traditional and novel fabrication techniques were discussed. The influence mechanisms of particulates on solidification microstructures, recrystallization behaviors, texture strength and twin behaviors of magnesium matrix composites during solidification and extrusion were summarized, and the roles of particulates in solidification and extrusion of magnesium matrix composites were analyzed. The strengthening mechanisms of particulates on the mechanical properties, corrosion resistance, fatigue resistance and creep resistance of magnesium matrix composites were revealed. Finally, the development prospect and research direction of magnesium matrix composites were prospected. It is hoped that this paper can provide a reference for the further development of magnesium matrix composites.

The semi-continuous (Mg,Al)2Ca second phase on Mg-Al-Ca-Mn alloys as an efficient anti-corrosion anode for Mg-air batteries

Developing high anti-corrosion and good discharge properties of magnesium based alloys for Mg-air batteries is still in challenge. In this work, a series of Mg-Al-Ca-Mn (AMX) alloys are prepared, and the second phases on AMX alloys are adjusting by varying the Al content. The AMX alloys with 3 wt% Al (denoted as AMX311) exhibits the excellent anti-corrosion behavior with a corrosion current density of 85.7 μA cm−2 and a low corrosion rate (4.1±0.21 mm y−1) in the 3.5 wt% NaCl solution. Furthermore, AMX311 shows lower hydrogen evolution volume (20.9±1 ml/cm2) and weight loss (5.8±0.3 mg) compared to other contrast samples. The outstanding electrochemical corrosion performance of AMX311 is attributed to the Al-rich oxide film which slowing corrosion at the initial stage and the formation of semi-continuous (Mg,Al)2Ca phase which can acts as a physical barrier to prevent the electrolyte from further corroding the magnesium matrix. Moreover, the AMX311 exhibits the highest discharge voltage (-1.471 V) and a peak specific energy of 1684.7±30.0 mW h g−1 at 20 mA/cm2, due to its superior corrosion resistance and reduced chunk effect. This work provides a good guide for designing advanced Mg-based alloys and an excellent insight into the effect of second phase on the corrosion and discharge performance of Mg-air batteries anode materials.

Microstructure, mechanical and tribological properties of Mg/CoCrFeNiMoTi high entropy alloy composites produced via FSP

In this study, multi-pass friction stir processing (FSP) was used to produce magnesium (Mg) matrix composites reinforced with CoCrFeNiMoTi high entropy alloy (HEA) particles. The effect of the HEA reinforcements on microstructure evaluation, mechanical properties (hardness and tensile) and wear performance was investigated. The composites were produced with similar pass number (three passes) and tool rotation speed (1250 rpm) and different tool transverse speeds (25 and 50 mm/min) and compared with the Mg matrix without reinforcing particles. XRD results indicated no significant reaction at the interface of the HEA and the matrix during FSP. Microstructure results showed the distribution improvement of the HEA reinforcements and elimination of lamellar structure (inhomogeneous structure) with the decrease of the tool transverse speed from 50 to 25 mm/min. Microstructures of all specimens illustrated four microstructural regions including stirring zone, thermo-mechanical affected zone, heat-affected zone and base metal. The average grain size of the stir zone reduced significantly from 12 µm for the Mg-50 to 2.5 µm and 1.6 µm for the Mg/HEAs-50 and Mg/HEAs-25 composites. The hardness value was increased from 34 HV for the base alloy to 113 HV for the FSPed composite at 25 mm/min (232 % improvement). The maximum yield and tensile strengths were obtained as 86.4 MPa and 114 MPa for the FSPed composite at 25 mm/min which presented enhancement of 92 % and 43 %, respectively as compared with the FSPed Mg alloy. The wear resistance results showed the reduction of the friction coefficient and wear rate with the addition of the HEA reinforcements with a considerable decrease in wear debris, groove depth, micro-cracks and delamination. Comparative plots confirmed that the hardening and strengthening effects of the HEA reinforcements were significantly higher than other reinforcements in Mg matrix composites.

Microstructure and Corrosion of Mg-Based Composites Produced from Custom-Made Powders of AZ31 and Ti6Al4V via Pulse Plasma Sintering.

Magnesium (Mg) and its alloys offer promise for aerospace, railway, and 3D technology applications, yet their inherent limitations, including inadequate strength, pose challenges. Magnesium matrix composites, particularly with metallic reinforcements like titanium (Ti) and its alloys, present a viable solution. Therefore, this study investigates the impact of Ti6Al4V reinforcement on AZ31 magnesium alloy composites produced using pulse plasma sintering (PPS). Results show enhanced microhardness of the materials due to improved densification and microstructural refinement. However, Ti6Al4V addition decreased corrosion resistance, leading to strong microgalvanic corrosion and substrate dissolution. Understanding these effects is crucial for designing Mg-based materials for industries like petrochemicals, where degradation-resistant materials are vital for high-pressure environments. This research provides valuable insights into developing Mg-Ti6Al4V composites with tailored properties for diverse industrial applications, highlighting the importance of considering corrosion behavior in material design. Further investigation is warranted to establish predictive correlations between Ti6Al4V content and corrosion rate for optimizing composite performance.

Development of Composite Materials Using Magnesium Matrix with Variations in the Addition of Volume Fractions of Nano-Al2O3 Reinforcement Results of the Stir Casting Method

Magnesium matrix composites were developed as a form of material selection that can save fuel use due to excess magnesium, which has very low specific gravity and still has good mechanical properties. In this study, a magnesium matrix composite with nano-Al2O3 reinforcement was successfully fabricated using the stir casting method. When compared with magnesium monolithic, the addition of nano-Al2O3 particles of 0.05, 0.10, 0.15, 0.20, and 0.25 %Vf in magnesium composite casting was investigated to improve the mechanical properties of Mg/nano-Al2O3 composites. Magnesium composites with 0.20% Vf reinforcement were found to be the best composition of impact price, wear rate, density, and porosity. This is because the more reinforcement given, the more mechanical properties increase, but the agglomeration tendency of nano-Al2O3 particles is higher so that at a composition of 0.25 %Vf, there is a mechanism anomaly because the reinforcement carried out is less homogeneous. In addition to the number of amplifiers, the improvement of mechanical properties is influenced by the fabrication process, i.e. stir casting. This study uses chemical characterization of OES, EDS, and XRD, hard damage, impact, wear, density and porosity testing, and metallographic observations using OM and SEM.

Optimizing microstructure and mechanical properties of bimodal-structured magnesium matrix composites by regulating the remelting time of powder thixoforming

A kind of bimodal graphene oxide (GO) reinforced ZK60 Mg matrix composite, characterized by the constitutes of fine grain (FG) zones reinforced by GO and coarse grain (CG) zones, was prepared via powder thixoforming, and its microstructure was optimized through adjusting the partial remelting time to achieve a desirable strength-ductility coordination. Both the volume fractions and grain sizes of CGs could be regulated at different levels by changing the heating duration. The composite thixoformed at 60 min, having 30.1 vol% CGs with average grain size of 15.2 μm, achieves the highest yield strength of 192 MPa and ultimate tensile strength of 316 MPa, as well as a high elongation of 21.8% and toughness of 61.9 MJ m−3, possessing the most remarkable coordination of strength and ductility among the as-reported homogeneous-structured Mg-6Zn composites reinforced by carbonaceous nanomaterials. The macroscopic strain of the composites becomes more uniform as the remelting time increases due to the enhanced co-deformation ability between FG and CG constitutes, which contributes to higher ductility. The back stress strengthening makes a large contribution to the strengthening of the composites. Bimodal structure induced toughening, enhanced dislocation storage capability of the FG zones, and crack blunting contribute to the toughness of the composites. This work provides a promising approach for designing and fabricating bimodal-structured metal matrix composites with good comprehensive mechanical performances.

Enhancing mechanical and wear performances of magnesium matrix composites using low-cost squid quill ash

The increasing demand for lightweight, cost-effective aerospace and automotive components with higher performance promotes interest in the use of naturally occurring materials, such as magnesium composites with natural and low-cost reinforcements. This research focuses on stir casting to reinforce magnesium matrix composites with squid quill ash (SQA) particles, aiming to improve their mechanical and wear performances. The results show that the mechanical and wear properties of magnesium matrix composites can be improved significantly by increasing the SQA content. Incorporating 10% SQA reinforcements in AZ91 magnesium alloy leads to a maximum increase in hardness, yield strength, and ultimate tensile strength by 32.34%, 18.86%, and 12.34%, respectively. When compared to the matrix alloy, the wear resistance of the composites reinforced with 5 wt% and 10 wt% of SQA particles is improved by 14.05% and 30.81%, respectively. These findings demonstrated the feasibility of using SQA particles in the production of magnesium matrix composites. This not only reduces environmental impact by repurposing SQA, but also provides a practical method for the economical utilization of SQA particles in the fabrication of magnesium matrix composites for aerospace and automotive applications.

Comparative study of CaO and CaCO3 on microstructure refinement, mechanical and corrosion resistance of AM60 alloy

Grain refinement is a crucial technique for enhancing the mechanical properties and corrosion resistance of magnesium alloys. In this study, the addition of 0.3 wt% CaO and 0.3 wt% CaCO3 successfully refined the AM60 alloy, resulting in a significant reduction in the average grain size from 326 μm to 96 μm (when adding CaCO3). The refined grain size of the as-cast AM60 alloy led to an increase in both tensile strength and yield strength to 118.2 MPa and 72.6 MPa, representing a respective increase of 35% and 23% compared to the alloy without the refiner. As results of EBSD, it is verified that the basal slip system (0001)<112‾0> has a higher Schmid factor after adding CaO, which indicates that this system has higher activity. The substitution reaction between CaO and Mg can produce synergistic effects from the solute effect of Ca and the nucleating effect of residual CaO, which play an important role in grain refinement. Due to the fine grain size and diffuse distribution of the second phase in the AM60-CaCO3 alloy and the thermal decomposition of CaCO3, which consumes the aluminum element in the matrix, the content of the β-phase (Mg17Al12) is reduced. Consequently, this reduces the electric coupling effect between the β-phase and the magnesium matrix. The AM60-CaCO3 alloy exhibited the most superior corrosion resistance, achieving a corrosion rate of only 1.01 mm y−1, representing a 48.9% reduction in corrosion rate compared to the AM60 alloy.

Research Progress and the Prospect of Damping Magnesium Alloys.

As the lightest structural metal material, magnesium alloys possess good casting properties, high electrical and thermal conductivity, high electromagnetic shielding, and excellent damping properties. With the increasing demand for lightweight, high-strength, and high-damping structural materials in aviation, automobiles, rail transit, and other industries with serious vibration and noise, damping magnesium alloy materials are becoming one of the important development directions of magnesium alloys. A comprehensive review of the progress in this field is conducive to the development of damping magnesium alloys. This review not only looks back on the traditional damping magnesium alloys represented by Mg-Zr alloys, Mg-Cu-Mn alloys, etc. but also introduces the new damping magnesium materials, such as magnesium matrix composites and porous magnesium. But up to now, there have still been some problems in the research of damping magnesium materials. The effect of spiral dislocation on damping is still unknown and needs to be studied; the contradiction between damping performance and mechanical properties still lacks a good balance method. In the future, the introduction of more diversified damping regulating methods, such as adding other elements and reinforcements, optimizing the manufacturing method of damping magnesium alloy, etc., to solve these issues, will be the development trend of damping magnesium materials.

Corrosion Behavior of Graphene Nanosheets Reinforced Magnesium Matrix Composites in Simulated Body Fluids

Corrosion Behavior of Graphene Nanosheets Reinforced Magnesium Matrix Composites in Simulated Body Fluids

Influence of machining process of MoS2/B4C/Az31 Mg alloy composite and its tribological characteristics

The automotive, biomedical, and aerospace industries are among those with a rising need for lightweight materials with enhanced mechanical and tribological qualities. Composites based on magnesium alloys have attracted interest because of their excellent strength-to-weight ratio and promise to improve component performance. Magnesium (Mg) alloy-based composites find applications in sports and leisure equipment, aerospace, biomedical implants, and more. The research outlined here serves a critical need in the field of materials science and engineering, particularly regarding the development of advanced magnesium (Mg) alloy-based composites. In this study, we have created a new aluminum composite using the AZ31 alloy mixed with 5% boron carbide (B4C) and 5% molybdenum disulfide (MoS2) as reinforcement through a powder metallurgical technique. The magnesium alloy contains 3% aluminum and 1% zinc. Our research aims to understand the mechanical and tribological behaviors and the impact of Electrical Discharge Machining (EDM) process parameters on AZ31 magnesium alloy. We need to modify these properties for various applications. Many industrial researchers have studied the machinability of magnesium alloys using EDM. We conducted wear tests on AZ31 alloy reinforced with both B4C and MoS2 in altered quantities using a pin-on-disc setup. The outcome displays that the wear resistance of these composites is considerably better matched to other magnesium matrix composites (MMCs). We also measured various densities of the hybrid composite, including apparent density, green density, and sintered density, which were found to be 0.839, 1.495, and 1.504 g/cm3, respectively—better than other composites. In addition, the hybrid composite exhibited a substantial increase in micro hardness, reaching 22.012 HV, indicating improved wear resistance of the material. Comparatively, low density, minimum wear profile, and maximum hardness were recorded for the sample of AZ31 + 5%MoS2 + 5%B4C. The influence of EDM parameters was discussed.

A Special Editor’s Issue on Magnesium Matrix Composites

A Special Editor’s Issue on Magnesium Matrix Composites

Improvement of strength and ductility of TC4p/AZ91D magnesium matrix composites by modifying the extrusion ratio

In this study, AZ91D (Mg-9Al-Zn) alloys reinforced with 2 vol% TC4 (Ti–6Al–4 V) particles fabricated by semi-solid stir casting were extruded at different ratios, resulting in observed grain refinement effects. The research findings demonstrate that both TC4 and β-Mg17Al12 phases contribute to promoting dynamic recrystallization (DRX) nucleation. With increasing extrusion ratio, the β-phase (Mg17Al12) gradually fractures into smaller particles, leading to progressive grain refinement. Furthermore, the transition from 〈01–10〉 fiber texture to non-basal texture in the α-Mg matrix after hot extrusion is attributed to improved DRX behavior and activation of non-basal slip. As the extrusion ratio increases, the tensile strength and elongation (EL) of TC4p/AZ91D composite improve significantly, reaching optimum comprehensive mechanical properties at an extrusion of 40:1 with a yield strength (YS) of 257 MPa, an ultimate tensile strength (UTS) of 357 MPa, and an EL of 9.7%. This remarkable strengthening effect is primarily attributed to β-phase reinforcement, grain refinement strengthening, and strain hardening.

Effects of process parameters on drilling of Magnesium-reinforced with B4C composite

The aerospace and defense industries could benefit from magnesium matrix composites because of their favorable mechanical and physical characteristics, in addition to their low density. Magnesium-based alloys and composites are also recognized for their biodegradability and biocompatibility, making them suitable for orthopedic implants. The addition of reinforcing elements significantly improves high specific strength to stiffness, wear resistance, damping, resistance to deformation under constant load, and resilience to repeated stress. Additionally, machinability is equally important during fitment in any such application. In this study, drilling experiments were conducted on Mg/B4C composites with two different volume reinforcement percentages (5% and 10%), and the results were compared under various cutting conditions. During the drilling process under different cutting conditions, the thrust force and torque were analyzed using a dynamometer and the surface roughness of the hole surface and chip formation were also analyzed for different conditions.

Optimizing CO2 laser beam welding parameters for magnesium hybrid metal matrix composites (ZE41A)

ABSTRACT The current work is the investigation of optimizing input welding parameters of CO2 laser welding of two stir squeeze casted magnesium (ZE41A) matrix silicon nitride and alumina-reinforced hybrid metal matrix composites (MMCs). Two similar hybrid MMC plates were joined by the CO2 laser beam welding process and were investigated for input welding parameters influencing the metallurgical and mechanical properties. The identified parameters were subjected to optimization by Box-Behnken experimental design of Response Surface Methodology (RSM) and the experimental trials were validated by Analysis of Variance (ANOVA). With increases of 16% and 23%, the microhardness and tensile strength peaked at 207 MPa and 78 HV, respectively. The ideal input welding settings were 3500W of laser power, 4 mm/minute welding speed, and a focus length of 1.5 mm.

Role of induced elastic deformations at the Mg/MgH2 transformation

The kinetics of magnesium hydride formation depends on many factors such as thermodynamic conditions, the presence/absence of additives and the mechanical treatments applied to the starting material. As a result, the impact on the reaction of the material is complex. Additionally, during repeated hydrogenation/dehydrogenation cycles, the microstructure of the material becomes significantly different from the original one. In such case, it is not so simple to order the relative importance of the different experimental contributions. In fact limited research efforts have been devoted to the impact of elastic deformation and its direct consequences on the hydride nucleation process. This motivates the present theoretical analysis of the mechanical energy balance between the Mg and MgH2 entities. Here the formation and interaction of a hydride nucleus with structural defects as a pore or a free surface is carried out in the Mg-MgH2 system.The present work evidences that calculation makes it possible to underline and unequivocally analyze the importance of a single parameter among a set of multiple factors that potentially have an impact on the kinetic processes. It is demonstrated here that due solely to the change in volume during hydride nucleation, conditions develops in the magnesium matrix for predominant release of hydride onto free surfaces, including pores.The calculation of the energy balance made it possible to classify the local impact on the nuclei for different typical configurations such as the vicinity of a free surface, a boundary and the vicinity of low rigidity defects (e.g. pores, vacancies, etc.). Hydride formation near a surface (external or internal, a twin plane or a grain boundary, etc.) results in a reduction in mechanical energy terms, which favors the easy nucleation step in magnesium. Nucleation occurs primarily on free surfaces rather than in bulk.