Magnesium-based Composites Research Articles

Fabrication of high-performance biomedical rare-earth magnesium alloy-based WE43/hydroxyapatite composites through multi-pass friction stir processing

Magnesium-based composites with bioactive ceramic particles addition are promising materials for biomedical implant applications. Nevertheless, the agglomeration of bioactive ceramic particles remains a challenge for fabricating high-performance biomedical magnesium-based composites. Herein, a novel high-performance biomedical rare-earth magnesium alloy-based WE43/hydroxyapatite (HA) composite is successfully fabricated via multi-pass friction stir processing (MP-FSP). Systematic investigations reveal that MP-FSP leads to a uniform distribution of HA particles and efficient elimination of defects. The microstructural analysis shows a significant grain refinement in the WE43 alloy from 49.4 μm to 2.4 μm under triple-passes FSP. The mechanical properties of the composite are enhanced significantly under triple-passes FSP, with yield strength, ultimate tensile strength, and elongation reaching 236.2 MPa, 278.6 MPa, and 14.2% respectively. Corrosion resistance is also improved, with a 30% reduction in the corrosion rate in SBF solution compared to the unprocessed alloy. Moreover, the MP-FSP fabricated composites exhibit superior corrosion-wear resistance, characterized by slight abrasive wear compared to the abrasive wear and severe pitting corrosion observed in the base WE43 alloy. These improvements are attributed to the synergistic effects of grain refinement, dispersion strengthening, enhanced interfacial bonding, and texture modification. Overall, these findings provide significant quantitative insights into the advanced fabrication techniques of magnesium-based composites for biomedical implant applications, highlighting the effectiveness of MP-FSP in enhancing both mechanical and corrosion-related properties.

Probing the Effect of Alloying Elements on the Interfacial Segregation Behavior and Electronic Properties of Mg/Ti Interface via First-Principles Calculations.

The interface connects the reinforced phase and the matrix of materials, with its microstructure and interfacial configurations directly impacting the overall performance of composites. In this study, utilizing seven atomic layers of Mg(0001) and Ti(0001) surface slab models, four different Mg(0001)/Ti(0001) interfaces with varying atomic stacking configurations were constructed. The calculated interface adhesion energy and electronic bonding information of the Mg(0001)/Ti(0001) interface reveal that the HCP2 interface configuration exhibits the best stability. Moreover, Si, Ca, Sc, V, Cr, Mn, Fe, Cu, Zn, Y, Zr, Nb, Mo, Sn, La, Ce, Nd, and Gd elements are introduced into the Mg/Ti interface layer or interfacial sublayer of the HCP2 configurations, and their interfacial segregation behavior is investigated systematically. The results indicate that Gd atom doping in the Mg(0001)/Ti(0001) interface exhibits the smallest heat of segregation, with a value of -5.83 eV. However, Ca and La atom doping in the Mg(0001)/Ti(0001) interface show larger heat of segregation, with values of 0.84 and 0.63 eV, respectively. This implies that the Gd atom exhibits a higher propensity to segregate at the interface, whereas the Ca and La atoms are less inclined to segregate. Moreover, the electronic density is thoroughly analyzed to elucidate the interfacial segregation behavior. The research findings presented in this paper offer valuable guidance and insights for designing the composition of magnesium-based composites.

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.

The Effectiveness Mechanisms of Carbon Nanotubes (CNTs) as Reinforcements for Magnesium-Based Composites for Biomedical Applications: A Review.

As a smart implant, magnesium (Mg) is highly biocompatible and non-toxic. In addition, the elastic modulus of Mg relative to other biodegradable metals (iron and zinc) is close to the elastic modulus of natural bone, making Mg an attractive alternative to hard tissues. However, high corrosion rates and low strength under load relative to bone are some challenges for the widespread use of Mg in orthopedics. Composite fabrication has proven to be an excellent way to improve the mechanical performance and corrosion control of Mg. As a result, their composites emerge as an innovative biodegradable material. Carbon nanotubes (CNTs) have superb properties like low density, high tensile strength, high strength-to-volume ratio, high thermal conductivity, and relatively good antibacterial properties. Therefore, using CNTs as reinforcements for the Mg matrix has been proposed as an essential option. However, the lack of understanding of the mechanisms of effectiveness in mechanical, corrosion, antibacterial, and cellular fields through the presence of CNTs as Mg matrix reinforcements is a challenge for their application. This review focuses on recent findings on Mg/CNT composites fabricated for biological applications. The literature mentions effective mechanisms for mechanical, corrosion, antimicrobial, and cellular domains with the presence of CNTs as reinforcements for Mg-based nanobiocomposites.

Synergistic effect of hybrid reinforcement on magnesium-based composites for enriching mechanical and tribological characteristics

The exceptional mechanical, microstructural, and tribological characteristics of friction stir processed (FSP) hybrid and mono nanocomposite materials resulted in growing research interest. In the presented work, the base matrix of magnesium-based AZ31B alloy was reinforced with fly ash (FA) and nano-titanium carbide (n-TiC) particulates using FSP and resulting in both hybrid and mono composite surfaces. The microstructures and homogeneous distribution of reinforcing particulates of the synthesized composites were investigated with optical microscopy (OM) and field emission scanning electron microscopy (FESEM). In addition, for the synthesized nanocomposites, mechanical and tribological characteristics were investigated including using tensile and compression strength, micro/nano-hardness, and wear characteristics. The OM and FESEM data indicate that owing to the significant impact of the FSP process, grain refinement and the homogenous dispersion of the FA and n-TiC nanoparticles for both mono and hybrid composites were achieved. Overall, the new nano-hybrid composites have better mechanical properties due to improved interfacial bonding and homogeneous dispersion of hybridized n-TiC/FA reinforcements. The results indicate that the AZ31B/FA/TiC hybrid nanocomposite has better mechanical and tribological characteristics than the base alloy and the mono composite materials. More specifically, the grain size was reduced nearly 20 times, microhardness was 1.72 times higher, ultimate tensile strength was 2.42 times higher, compressive strength was 2.57 times higher, and wear rate was, about 80% higher when contrasted to the base alloy. Lastly, it is expected that this composite can offer a remarkable solution for crafting high-performance automotive parts.

Physicomechanical, morphological and tribo-deformation characteristics of lightweight WC/AZ31B Mg-matrix biocomposites for hip joint applications.

Exploring high strength materials with a higher concentration of reinforcements in the alloy proves to be a challenging task. This research has explored magnesium-based composites (AZ31B alloy) with tungsten carbide reinforcements, enhancing strength for medical joint replacements via league championship optimisation. The primary objective is to enhance medical joint replacement biomaterials employing magnesium-based composites, emphasising the AZ31B alloy with tungsten carbide reinforcements. The stir casting method is utilised in the manufacture of magnesium matrix composites (MMCs), including varied percentages of tungsten carbide (WC). The mechanical characteristics, such as micro-hardness, tensile strength, and yield strength, have been assessed and compared with computational simulations. The wear studies have been carried out to analyse the tribological behaviour of the composites. Additionally, this study investigates the prediction of stress and the distribution of forces inside bone and joint structures, therefore offering significant contributions to the field of biomedical research. This research contemplates the use of magnesium-based MMCs for the discovery of biomaterials suitable for medical joint replacement. The study focuses on the magnesium alloy AZ31B, with particles ranging in size from 40 to 60 microns used as the matrix material. Moreover, the outcomes have revealed that when combined with MMCs based on AZ31B-magnesium matrix, the WC particle emerges as highly effective reinforcements for the fabrication of lightweight, high-strength biomedical composites. This study uses the league championship optimisation (LCO) approach to identify critical variables impacting the synthesis of Mg MMCs from an AZ31B-based magnesium alloy. The scanning electron microscopy (SEM) images are meticulously analysed to depict the dispersion of WC particulates and the interface among the magnesium (Mg) matrix and WC reinforcement. The SEM analysis has explored the mechanisms underlying particle pull-out, the characteristics of inter-particle zones, and the influence of the AZ31B matrix on the enhancement of the mechanical characteristics of the composites. The application of finite element analysis (FEA) is being used in order to make predictions regarding the distribution of stress and the interactions of forces within the model of the hip joint. This study has compared the physico-mechanical and tribological characteristics of WC to distinct combinations of 0%, 5%, 10% and 15%, and its impact on the performance improvements. SEM analysis has confirmed the findings' improved strength and hardness, particularly when 10%-15% of WC was incorporated. Following the incorporation of 10% of WC particles within Mg-alloy matrix, the outcomes of the study has exhibited enhanced strength and hardness, which furthermore has been evident by utilising SEM analysis. Using ANSYS, structural deformation and stress levels are predicted, along with strength characteristics such as additional hardness of 71 HRC, tensile strength of 140-150 MPa, and yield strength closer to 100-110 MPa. The simulations yield significant insights into the behaviour of the joint under various loading conditions, thus enhancing the study's significance in biomedical environments.

Mechanical Properties Enhancement of AZ91 Magnesium Alloy Reinforced with Various Ratios of Titanium Particles and Processed by ECAP

This study utilized AZ91 magnesium-aluminum alloy as the matrix for magnesium-based composites, reinforced with micron-sized titanium (Ti). Gravity casting and mechanical stirring were employed to fabricate specimens with 0 wt.%, 0.3 wt.%, and 0.5 wt.% Ti reinforcement. Heat-treated samples underwent Equal Channel Angular Pressing (ECAP), and microstructures were analyzed via SEM and XRD. The experimental results demonstrate that the addition of micron-sized titanium improves the yield strength, ultimate tensile strength, and hardness. The inclusion of 0.5 wt.% titanium powder resulted in a 17.5% increase in ultimate tensile strength and a 37% increase in yield strength. After secondary processing with ECAP, the ultimate tensile strength showed an additional 25% increase, while the yield strength increased by 13.5%. Vickers hardness test results reveal a significant 13.7% strength improvement with the addition of 0.5 wt.% titanium powder, and after ECAP secondary processing, there was a marginal additional increase of 0.8%.

Development of high strength and corrosion resistance Mg-Zn-Dy/HA-Ag composite for temporary implant applications

The present study focused on developing the high strength and corrosion resistant magnesium-based composites for temporary implant applications. For this, hydroxyapatite (HA)-silver (Ag) coated Mg-Zn-Dy alloy is subjected to friction stir processing to develop surface composite (F-HAg). The developed surface composite exhibited good mechanical properties and higher corrosion resistance, which was attributed to the significant grain refinement, strong basal structure and presence of high fraction of high angle grain boundaries. Indeed, the results of this study indicate that the fabricated surface composite is a potential material for bioabsorbable implant applications.

The Effect of Graphene Nanoplatelets Content on the Hardness of Mg6%Zn0.2%Mn Composites

The effect of graphene nanoplatelets (GNPs) content on the hardness of magnesium-based composites was studied. A magnesium-based composite, Mg6%Zn0.2%Mn with graphene nanoplatelets (GNPs), was fabricated via powder metallurgy process at room temperature and compressive pressures of 50kN for 20 minutes, which was then sintered at 500°C for 2 hours. It produced significant grain refinement microstructure. The change in microstructure was examined by 3D microscope analysis, and the hardness value was evaluated using the Vickers microhardness apparatus. This study demonstrated the importance of GNPs reinforcement with zinc and manganese for microhardness analysis in the sintered Mg-based GNPs composites. It also portrayed their influence on grain refinement of the microstructure. The hardness results agreed with the microstructure results, proving that the presence of GNPs increases the hardness of the Mg-based composites.

FRICTION STIR PROCESSING AND CLADDING: AN INNOVATIVE SURFACE ENGINEERING TECHNIQUE TO TAILOR MAGNESIUM-BASED ALLOYS FOR BIOMEDICAL IMPLANTS

Regarding biocompatibility, toxicity, degradation, and interaction with body cells, the materials as well as fabrication process used for biomedical implants are crucial aspects. Implant materials are chosen in accordance with these criteria. The most recent medical implants are made of materials, i.e. stainless steel, Co–Cr and titanium alloys. Although these conventional implant materials generate hazardous ions and have a stress shield effect in many medical implant situations, the implants must be removed from the body within a certain period of time. In order to avoid the need for implant removal, researchers advise using magnesium metal matrix composite (Mg-MMC) as an implant material. Magnesium composites are subjected to a variety of engineering processes to enhance their mechanical and biocompatibility properties, including the addition of reinforcement, treating the surface, and changing the synthesis processes. The solid-state “friction stir process” is discussed for the fabrication of magnesium metal matrix composites. The influence of various reinforcing materials’, process parameters and reinforcing strategies are summarized in this review study with respect to the microstructure, mechanical characteristics, and corrosion behavior of biodegradable magnesium matrix composites. This study provides an importance of magnesium-based composites for biomedical implants and the degradation behavior reduces the secondary activities to remove implants.

Synergistic effect of hybrid reduced graphene oxide (rGO) and carbon nanotubes (CNTs) reinforcement on microstructure, mechanical and biological properties of magnesium-based composite

Magnesium (Mg) was considered as a new kind of biomaterial implant due to its biodegradability and biocompatibility. Nevertheless, sufficient mechanical properties and low degradation rates in physiological environments are required. In this research, we have demonstrated that a network structure is developed from the reduced graphene oxide (rGO) and carbon nanotubes (CNTs), which inhibited face-to-face aggregation of rGO nano-platelets by straight CNTs inserted into adjacent rGO nano-platelets. The combination of rGO and CNTs was then used to strengthen the Mg-based nanocomposite fabricated using semi-powder metallurgy. The compressive strength and strain to fracture were maximally achieved 326.7 MPa and 11.58%, respectively for composite with 0.16 wt% CNTs and 0.5 wt% rGO. It was due to the effective load transfer and energy absorption of rGO and CNTs. Mechanisms for crack tip shielding, crack bridging and crack deflection was found to be responsible for mechanical enhancement. The electrochemical tests showed that the composite with the lowest CNTs concentration has the best corrosion resistance. In addition, the apatite-forming ability of composite in simulated body fluid (SBF) and cell culture experiments demonstrated favorable composite bioactivity and biocompatibility. Evaluation of the antibacterial activity showed that the growth and penetration of Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) bacteria could be significantly inhibited with increasing rGO-CNTs hybrid content in Mg alloy. This study may open the doors to the fabrication of Mg-based nanocomposite implants containing rGO-CNTs hybrid fillers for load-bearing applications.

Processing of Mg–Ca/tricalcium phosphate composites and their electrochemical properties in a cell culture medium

Biodegradable magnesium-based composites have recently attracted considerable attention for use in orthopedic implants on account of not only their biocompatibility but also the possibility of tuning their mechanical and corrosion properties. In this study, the effects of the fraction of tricalcium phosphate (TCP) and its crystal structure on the electrochemical properties in Eagle's minimal essential medium as well as the mechanical properties were examined using high-strength Mg–Ca/TCP composites with a fine-grained matrix (grain size: 1.2 µm) and relatively uniform TCP particle dispersion. The composites were prepared by extruding mixtures of the component powders at 540 K and exhibited high compressive yield strengths exceeding 290 MPa. Electrochemical tests revealed that the corrosion parameters were insensitive to both the fraction of TCP particles and their crystal structure. The fine-grained matrix may have overwhelmed the ability of the TCP dispersion to serve as a corrosion inhibitor. The chemical compositions of the cracked surface layer on the matrix and the white discontinuous corrosion products of the composites formed after the electrochemical tests were similar to those of the parent alloy.

Investigation of mechanical properties and antibacterial behavior of WE43 magnesium-based nanocomposite

The aim of this study is to develop a biodegradable magnesium-based nanocomposite with enhanced mechanical and antibacterial properties. To achieve this goal, nano- and micro-scale zinc oxide (ZnO) and copper-zinc oxide (Cu/ZnO) reinforcements were incorporated into WE43 magnesium alloy, as the matrix of the nanocomposite. High purity ZnO and Cu/ZnO were synthesized by solution combustion with citric acid fuel using conventional and microwave heating, resulting in nanometer and micrometer particles, respectively. Friction stir processing (FSP) was employed to develope the magnesium-based composites. ZnO and Cu/ZnO powders were implemented into the WE43 base plate with either drilling holes or machining grooves. Hole-inserted additives resulted in more uniform particle distribution than groove-inserted ones. In addition, nanoscale ZnO and Cu/ZnO particles showed more uniform distribution compared to microscale ZnO. The addition of Cu/ZnO particles yielded the highest level of antibacterial activity, compressive strength and micro hardness of the composite. The antibacterial performance of the composite was in line with the fact that Cu/ZnO powder showed more pronounced antibacterial properties than ZnO powders. In addition, groove-inserted Cu/ZnO composite showed compressive strength of 527 MPa and hardness of 90.7 Hv, which were significantly higher than the values of 300 MPa and 78.7 Hv obtained for groove-inserted ZnO composites. It should be noted that the un-processed monolithic WE43 alloy had a compressive strength of 138 MPa and hardness of 66.8 Hv.

Latest research and developments of ceramic reinforced magnesium matrix composites—A comprehensive review

High-performance lightweight materials give rise to a demand for magnesium-based composites. Magnesium metal matrix composites have found extensive applications in the aerospace and automotive industries due to their remarkable mechanical properties. Limitations in dispersion, strength, and interface strength of magnesium-based composites are seen through the addition of some hybrid reinforcements and different fabrication techniques. In this regard, previous studies have demonstrated the ability of various reinforcements such as graphene, carbon nano tubes, silicon carbide, and titanium carbide to a magnesium matrix for the enhancement of its metallurgical properties. There are still several challenges in the development of magnesium metal matrix composites, such as non-homogeneous distribution, poor creep resistance at elevated temperatures, limited cold work ability, and low corrosion resistance. The challenges that need to be overcome and suggestion for improving the wear resistance and frictional properties of magnesium metal matrix composites were studied and discussed. This review evaluates the importance of different reinforcement percentages as well as the development of magnesium metal matrix composites. The different types of fabrication techniques that are well suited to overcome the challenges of poor dispersing, non-homogeneous distribution, interfacial problems, and poor wettability are discussed. Microstructure analysis, the agglomerating effect, and matrix bonding strength are also discussed. The challenges and future scope of research are discussed for the demonstration of the importance of more scientific studies in magnesium metal matrix composites.

Wear Characteristics of Mg Alloy AZ91 Reinforced with Oriented Short Carbon Fibers.

Light-weight metal matrix composites, especially magnesium-based composites, have recently become more widespread for high-efficiency applications, including aerospace, automobile, defense, and telecommunication industries. The squeeze cast AZ91 base material (AZ91-BM) and its composites having 23 vol.% short carbon fibers were fabricated and investigated. The composite specimens were machined normal to the reinforced plane (Composite-N) and parallel to the reinforced plane (Composite-P). All the as-casted materials were subjected to different tests, such as hardness, compression, and wear testing, evaluating the mechanical properties. Dry wear tests were performed using a pin-on-disk machine at room temperature under different applied wear loads (1–5 N) and different sliding distances (– m). The microstructures and worn surfaces of the fabricated AZ91-BM and the two composite specimens were investigated using a scanning electron microscope (SEM) equipped with an energy dispersive spectroscopy (EDS) advanced analysis system. The wear debris was collected and investigated also under the SEM. The results showed significant improvement in hardness, compressive strength, and wear resistance of the composite specimens (Composite-N and Composite-P) over the AZ91-BM. The compressive strength and wear resistance are more fibers orientation sensitive than the hardness results. When the fiber orientation is parallel to the sliding direction (Composite-N), the weight loss is somewhat lower than that of the fiber orientation perpendicular to the sliding direction (Composite-P) at a constant wear load of 2 N and the sliding distances of , and m. In contrast, the weight loss of Composite-P is lower than Composite-N, especially at the highest sliding distance of m due to the continuous feeding of graphite lubricant film and the higher compressive strength. Plastic deformation, oxidation, and abrasive wear are the dominant wear mechanisms of AZ91-BM; in contrast, abrasive and delamination wear are mainly the wear mechanisms of the two composites under the applied testing conditions.

An investigation of microstructural background for improved corrosion resistance of WE43 magnesium-based composites with ZnO and Cu/ZnO additions

In this research, WE43-based nanocomposites were fabricated by addition of nano- and micro-sized particles of ZnO and Cu/ZnO, followed by friction stir processing (FSP). In addition to the effect of the size of additives, the effect of geometry of the particle insertions, groove and holes, on the evolution of microstructure and corrosion properties of Mg-based composites were studied. The grain size of the matrix of the fabricated composite was reduced after FSP. In addition, significant fragmentation and re-distribution of secondary phase particles occurred which resulted in size reduction, increased density and improved uniformity of the particles. Corrosion behavior of the composite was assessed by scrutinizing potentiodynamic polarization, electrochemical impedance spectroscopy, cyclic polarization and immersion tests. It was found that the corrosion mechanism of Mg-based nanocomposite samples was a combination of pitting and uniform corrosion. Furthermore, the rate of electrochemical corrosive reactions reduces by performing FSP and addition of particles. The composite fabricated using hole insertion and nano-sized particles showed a more uniform distribution of additives resulting in higher corrosion resistance in comparison with groove insertion. In addition, fabricated composite sample with Cu/ZnO particles presents the highest anti-corrosion properties. • A new Mg-based composite with ZnO and Cu/ZnO powders as reinforcing factors is developed by friction stir processing (FSP). • A composite with refined grains, redistribution of secondary phase particles and uniform distribution of ZnO and Cu/ZnO powders is fabricated. • Reduction of grain size and redistribution of secondary phase particles has a remarkable positive effect on improvement of corrosion resistance . • Because of presence of ZnO and ZnO particles, corrosion resistance of resultant composite is improved and localized corrosion is reduced. • Improved biocompatibility is observed due to the positive influences of ZnO and Cu/ZnO particles.

Effect of Zinc and Bio-Glass Addition on Mechanical Properties and Corrosion Behavior of Magnesium-Based Composites for Orthopedic Application: A Preliminary Study

Effect of Zinc and Bio-Glass Addition on Mechanical Properties and Corrosion Behavior of Magnesium-Based Composites for Orthopedic Application: A Preliminary Study

Study of Influence of Aluminum Nitride Nanoparticles on the Structure, Phase Composition and Mechanical Properties of AZ91 Alloy

In this work, magnesium-based composites were obtained by shock-wave compaction of a powder mixture of Mg-5 wt.% AlN at a shock-wave pressure of 2 GPa. Their microstructure was investigated and the phase composition was determined, from which it follows that the nanoparticles retain their phase composition and are uniformly distributed in the magnesium matrix. The materials obtained by shock-wave compaction were used as master alloys for the production of magnesium alloys by die casting. The amount of aluminum nitride nanoparticles in the AZ91 magnesium alloy was 0.5 wt.%. Studies of the microstructure of the magnesium alloys showed a decrease in the average grain size of the magnesium matrix from 610 to 420 μm. Studies of mechanical properties have shown that the introduction of aluminum nitride nanoparticles increases the yield strength from 55 to 119 MPa, the tensile strength from 122 to 171 MPa and the plasticity from 4 to 6.5%, respectively. The effect of nanoparticles on the fracture behavior of the magnesium alloy under tension was determined.

A review of the design, processes, and properties of Mg-based composites

Abstract Magnesium-based composites are promising materials that can achieve higher strength, modulus, stiffness, and wear resistance by using metals, ceramics, and nanoscale carbon-based materials as reinforcements. In the last few decades, high-performance magnesium-based composites with excellent interfacial bonding and uniformly distributed reinforcements have been successfully synthesized using different techniques. The yield strength, Young’s modulus, and elongation of SiC nanoparticle-reinforced Mg composites reached ∼710 MPa, ∼86 GPa, and ∼50%, respectively, which are the highest reported values for Mg-based composites. The present work summarizes the commonly used reinforcements of magnesium composites, particularly nano-reinforcements. The fabrication processes, mechanical properties, reinforcement dispersion, strengthening mechanisms, and interface optimization of these composites are introduced, and the factors affecting these properties are explained. Finally, the scope of future research in this field is discussed.

The Effect of Co-Encapsulated GO-Cu Nanofillers on Mechanical Properties, Cell Response, and Antibacterial Activities of Mg-Zn Composite

Magnesium-based composites have recently been studied as biodegradable materials for preparing orthopedic implants. In this article, the graphene oxide (GO) and GO-Cu nanosystem has been homogenously dispersed as a reinforcement in the matrix of Mg-Zn (MZ) alloy using the semi powder metallurgy (SPM) method, and subsequently, the composite has been successfully manufactured using the spark plasma sintering (SPS) process. GO and GO-Cu reinforced composite displayed a higher compressive strength (~55%) than the unreinforced Mg-Zn sample. GO and GO-Cu dual nanofillers presented a synergistic effect on enhancing the effectiveness of load transfer and crack deflection in the Mg-based matrix. Besides, the GO-Cu dual nanofillers displayed a synergistic influence on antibacterial activity through combining the capturing influences of GO nanosheets with the killing influences of Cu. However, electrochemical and in-vitro immersion evaluation showed that Cu-GO reinforcement had a slightly negative effect on the corrosion behavior of the Mg-Zn sample, but the incorporation of GO enhanced corrosion resistance of the composite. Moreover, MZ/GO and MZ/GO-Cu nanocomposites showed acceptable cytotoxicity to MG-63 cells and revealed a high potential for use as an orthopedic implant material. Based on the research results, MZ/GO-Cu nanocomposite could be used in bone tissue engineering applications.