Magnesium Metal Matrix Composites Research Articles

Graphene reinforced magnesium metal matrix composites by infiltrating coated-graphene preform with melt

Graphene’s exceptional mechanical, electrical, and thermal conductivity capabilities make it an ideal reinforcement for metal matrix composites. However, graphene is hard to be dispersed in the melt metal due to its high surface energy, non-wetting nature, and strong van der Waals interactions between graphene sheets, which weaken the reinforcing efficiency of composites. A novel process by infiltrating the coated-graphene preform with melt magnesium was proposed to improve the dispersion of graphene in the magnesium matrix. Graphene preforms with oriented pores were prepared by a directional freeze-drying method. Magnesium oxide coatings were deposited on the surface of graphene inside the graphene preform using the evaporation of magnesium atoms to enhance the strength as well as the wettability between the preform and magnesium matrix. Magnesium matrix composites were fabricated by liquid-solid pressure infiltrating coated-graphene preform with molten magnesium. The microstructure of graphene preforms and composites and mechanical properties of the composites were characterized. The results show that graphene is uniformly dispersed in the matrix and presents a reticular structure, and the hardness, elastic modulus, and compressive strength of the composite were improved apparently compared to the matrix. This study suggests that the method of preparing composites by infiltration provides a novel strategy for fabricating nano-material reinforced magnesium matrix composites.

A Review on Mechanical and Wear Characteristics of Magnesium Metal Matrix Composites with Machine Learning Modelling

A Review on Mechanical and Wear Characteristics of Magnesium Metal Matrix Composites with Machine Learning Modelling

Effect of sliding speed and sliding distance on wear behavior of AZ31-B4C composite

Emphasis of current research is to investigate the dry sliding behavior of AZ31 magnesium alloy and AZ31–1.5B4C magnesium metal matrix composites (MMCs) at varying sliding speeds and sliding distances. Magnesium alloy and composite are fabricated through ultrasonic assisted stir casting method. Optical microscope (OM), scanning electron microscopy (SEM), and energy dispersive x-ray analysis (EDAX) are used to characterize developed materials. Microhardness of all materials is measured using a Vickers microhardness tester. Wear-friction behavior is investigated in dry sliding mode using pin-on-disc tribometer at room temperature. Magnesium alloy and composite are tested over a range of sliding speeds (0.25–1.25 m s−1) and distances at a moderate normal load (20N). Wear morphology is finally investigated for composites and alloy under SEM and EDAX. SEM micrographs of as-cast AZ31-1.5B4C composite reveals uniform distribution of B4C particles with noticeable refinement in grain structure. EDAX spectra of AZ31-1.5B4C composite depict the presence of boron and carbon along with existing elements of AZ31 alloy. Microhardness has enhanced around 30% for Mg-MMC by incorporating 1.5 wt% B4C in AZ31 alloy. Furthermore, the use of B4C as reinforcement increases the density of the composite. Wear rate is reduced by around 20% and COF is reduced by around 25% for AZ31-1.5B4C composite compared to AZ31 alloy for all experimental conditions. Abrasion, oxidation, adhesion and delamination wear mechanisms are observed as dominant mechanism for varying sliding speeds and distances.

Investigation into the mechanical properties of heat-treated magnesium metal matrix composites reinforced with TiO2 and Sn particles

Investigation into the mechanical properties of heat-treated magnesium metal matrix composites reinforced with TiO2 and Sn particles

Microstructure, mechanical properties and wear behavior of Mg matrix composites reinforced with Ti and nano SiC particles

This study examines the mechanical properties and wear mechanisms of magnesium (Mg) metal matrix composites reinforced with titanium (Ti) and silicon carbide (SiC) particles. Three different composite formulations were investigated: Mg-30 wt% Ti (A), Mg-25 wt% Ti-5 wt.% SiC (NB), Mg-20 wt% Ti-10 wt% SiC (NC), and Mg-15 wt% Ti-15 wt% SiC (ND). These composites were fabricated through ball milling and spark plasma sintering (SPS). The incorporation of SiC particles significantly enhanced grain refinement and phase formation within the composites. Density analysis revealed that the actual densities of the composites were lower than the theoretical values, with Composite A exhibiting the highest actual density of 2.15 g/cm³ and the lowest porosity of 16.31%. The introduction of SiC particles increased porosity, with Composite NB displaying the highest porosity at 30.58%. Hardness testing indicated that Composite NC, containing 10 wt% SiC, achieved the highest hardness of 137 HV. In contrast, Composite ND, with 15 wt% SiC, showed a reduced hardness of 115 HV, attributed to increased porosity and potential SiC particle agglomeration. Wear behavior was evaluated using a pin-on-disc tribometer. Weight loss measurements indicated that Composite A had the lowest weight loss (1.1–2.1 mg), while Composite NB experienced the highest weight loss (2.8–8.3 mg) due to increased porosity. Composite NC demonstrated a balance with moderate weight loss (2.0–3.8 mg). The coefficient of friction (COF) varied with SiC content and applied loads (2, 4, and 8 N), with Composite A demonstrating the lowest COF values (2.3–2.8) and stable performance across different loads. Composite NB exhibited higher COF values (3.5–4) and significant fluctuations due to elevated porosity and the presence of SiC particles. Composite NC showed better wear resistance and more stable COF values (2.5–2.9) compared to NB and ND.

Experimental Investigation of WE43(T6) magnesium metal matrix composites to enhance mechanical properties and EDM process parameters

In recent years, magnesium metal matrix composites (MMCs) are increasingly used in the automotive, aerospace, and biomedical industries due to their superior physical and thermal properties compared to their parent materials. Magnesium metal matrix composites are noteworthy for numerous reasons, including their light weight, high specific modulus, wear resistance, corrosion resistance, high toughness, fracture resistance, thermal stability, and ability to perform at higher temperatures. Our research primarily focuses on enhancing the mechanical properties of the magnesium metal matrix composite (WE43-T6) reinforced by silicon carbide (SiC) and aluminum oxide (Al2O3) particles with a size of 10 μm to 30 μm. The composite was examined using SEM and EDAX to investigate its microstructure and elemental composition. The distribution of the reinforcement particles is well represented in the microstructural analysis. In addition, the present research also focuses on studying MRR, TWR, and surface roughness in EDM machining process using copper, brass, and tungsten carbide electrodes to improve MRR and limit TWR and surface roughness. The results of the study showed that pulse on-time, pulse current, and spindle speed have a significant influence on MRR and TWR. A parametric analysis using a linear regression model was performed to verify the effects of experimental machining performance The experimental results were found to have less than 5% error. The addition of silicon carbide and aluminum oxide particles to magnesium metal matrix composites, makes materials harder and stronger while reducing their weight by 0.98–1.05%.

Investigation on Mechanical and Fracture Behavior of Magnesium Composite Reinforced With Hybrid Fly Ash Particulates Synthesized via Friction Stir Processing Route

Abstract Utilizing waste materials like fly ash in the creation of lightweight magnesium metal matrix composites with a high strength-to-weight ratio is encouraged by the rising demand for in-expensive reinforcements. In the current study, friction stir processing (FSP) was employed to synthesize magnesium surface composites via incorporating hybrid reinforcement particles, including nano titanium carbide and fly ash. The synthesized composite material underwent examination through microscopic images of the stir zone and assessments of microhardness, tensile strength, compressive strength, electrical and thermal conductance, and wear behavior. The results revealed a notable refinement in grain size and a simultaneous improvement in mechanical properties. Notably, there was a substantial increase in wear resistance attributed to the increased hardness and uniform dispersion of hybrid reinforcements within the surface composite. The results demonstrate that the inclusion of reinforcements in magnesium-based alloy led to an enhancement in fracture toughness, mitigation of crack propagation, and an overall improvement in fracture resistance to catastrophic failure.

Synthesis and characterization of magnesium-titanium carbide nanocomposites via friction stir processing: An in-depth parameter investigation

Magnesium Metal Matrix Composites (MMMCs) possess remarkable mechanical and metallurgical properties that have garnered the interest of researchers worldwide. The current research endeavors to synthesize nanocomposites based on magnesium (Mg), specifically AZ31B, by employing Friction Stir Processing (FSP) and integrating nano-titanium carbide (TiC) as a reinforcing element. Additionally, the impact of various FSP parameters, encompassing transverse speeds (35 and 70 mm/min) and tool rotation speeds (850 and 1700 rpm), on the metallurgical, wear, and mechanical properties of the developed MMMCs was investigated. The microstructural analysis revealed that employing the FSP technique led to a uniform dispersion of nano-TiC reinforcement particles within the base matrix of the AZ31B Mg alloy. This concurrent distribution played a crucial role in both refining and evolving the grain sizes, subsequently leading to improvements in the composites’s mechanical and wear characteristics. To be more specific, the grain size witnessed a reduction by nearly 18 times, the microhardness increased by approximately 2.54 times, and the ultimate tensile strength (UTS) showed a 2.08-fold increase when compared to the base alloy. Furthermore, in contrast to the base material characterized by an adhesive wear mechanism, the presence of scratches indicates that the abrasive wear mechanism predominated in the case of the AZ31B/TiC nanocomposite. The outcome of the results depicts that the nanocomposite fabricated at a tool rotation speed of 1700 rpm and 70 mm/min transverse shows better mechanical and tribological characteristics than other developed composites and the base alloy.

Investigation and characteristics of AZ91 magnesium metal matrix composite using the powder metallurgy process

This paper aims to investigate the mechanical and metallurgical properties of magnesium AZ91 composite. Zinc and Aluminium were selected as reinforcement particles in the Magnesium metal matrix composite. The composites 88.5%Mg-9%Al-1.5%Mn-1%Zn, 87.5%Mg-9%Al-2.5%Mn-1%Zn, 86.5%Mg-9%Al-3.5%Mn- 1%Zn, 85.5Mg-9%Al-4.5%Mn-1%Zn, 84.5%Mg-9%Al-5.5%Mn-1%Zn and 83.5%Mg-9%Al-6.5%Mn-1%Zn are prepared through powder metallurgy. The hardness and compressive tests are used to investigate the mechanical properties of the magnesium composite. The results of the mechanical properties indicate that manganese plays a vital role in improving the hardness of the AZ91 composite. The thermogravimetric analysis investigated the weight ratio % at the 400OC. The scanning electron. microscopic analysis was used to investigate the reinforcement particle's bonding level and the defects on the composite. Based on the results, the manganese plays a vital role in improving the mechanical properties of the AZ91 composite.
 KEY WORDS: Magnesium, Composite, Mechanical properties, Hardness, Compressive, Corrosive behaviour
 Bull. Chem. Soc. Ethiop. 2024, 38(2), 305-312. 
 DOI: https://dx.doi.org/10.4314/bcse.v38i2.3

Stir casting technology for fabrication of biodegradable magnesium metal matrix composites containing different percentages of hydroxyapatite reinforcement material for biomedical purposes

Due to the superior biocompatibility and strength of magnesium and its alloys compared to other metallic alloys, such as those used in orthopaedics as a bone-implant material, they have recently been considered a breakthrough material for biomedical applications. However, before tissues have fully adjusted to the high chloride environment and physiological pH range of the physiological system, pure magnesium might lose its mechanical integrity. Therefore, it is believed that the development of magnesium matrix composites is an approach to decrease corrosion rates and improve their mechanical properties that are similar to those of natural bone. They are not required to be taken out once the wound has entirely healed because they are biodegradable as well, which might reduce the need for additional surgeries in the future. The stir casting technique has been employed in this workto produce samples of magnesium-based biodegradable metal matrix composites, referred to as M2H (Magnesium & 2.0 wt% Hydroxyapatite powder) and M4H (Magnesium & 4.0 wt% Hydroxyapatite powder), with varying amounts of hydroxyapatite powder as a reinforcement material. In this worktensile test samples (M2H-T1,T2 & M4H-T1,T2) andcompression test samples (M2H-C1,C2,C3& M4H-C1,C2,C3,C4)along with microstructural and SEM test samples (M2H-MS & M4H-MS)were prepared and cut to a suitable shape and size in accordance with ASTM standards. This paper mainly focuses on the samples preparation for mechanical testing and SEM characterisation.

Exploring the effects of self-lubricating MoS2 in magnesium metal matrix composite: Investigation on wear, corrosion, and mechanical properties

The prime focus of this experimentation is to develop a lightweight self-lubricating surface composite with superior wear resistance. This article inquires into the consequences of Molybdenum di Sulphide (MoS2) for its 2, 4, and 6 vol% dispersion on magnesium surface by applying friction stir processing (FSP). The prepared composites were analysed for their microstructure, mechanical, and wear characteristics. The observation of the microstructure reveals the smaller grain size as a result crystallization process occurring during FSP and the uniform dispersion of reinforced particles. The surface composite shows a growing tendency in its hardness which can be assumed as the outcome of the reduced grain size and reinforcement dispersion. On the other hand, the developed composite exhibited lower tensile characteristics than the base matrix. The composite shows constructive enhancement in wear resistance with the increase in the vol% of MoS2 particles whereas the increase in load increases the wear rate. The value of the corrosion rate is decreased up to 60 % with 2 % reinforcement addition whereas further addition resulted in a higher corrosion rate.

Fabrication & investigation of properties of hybrid surface composite of magnesium matrix reinforced with aluminum & zinc by friction stir processing

Pure magnesium, despite its advantages, lacks crucial strength and corrosion resistance. With a continuous quest for improved materials and techniques, this study investigates innovative composite materials and the use of FSP for broader industrial applications. The study succeeded in producing this composite with enhanced properties compared to pure magnesium. Notably, the composite exhibited better corrosion resistance, increased strength and hardness. The grain size in the stir zone was significantly smaller, the grain structure was fine without defects, and recrystallized grains were present, resulting in more grain boundaries. Importantly, the properties of this surface composite approached or even surpassed those of some conventionally cast magnesium metal matrix composites. This suggests the potential for using this surface composite and FSP in industrial applications with further process parameter optimization. These findings highlight the promising prospects of surface composites and FSP in replacing traditional methods and bulk composites in specific industries.

Influence of Lanthanum oxide on AZ31 magnesium composite properties

Magnesium metal matrix composites are used for wear-resistance applications such as engine liners, cylinder blocks, and friction materials. In this study, AZ31+(0.5 to 2 wt%) La2O3 composites are prepared through a powder metallurgy process. Notably, when the percentage of La2O3 increase, the density of reinforced composites increases by 3%, and hardness increase by 25%. The microstructure mapping shows the homogeneous distribution of Mg, Al, Zn, La, and O elements throughout the composites. AZ31 + 1.5 wt% La2O3 composite has the lowest friction coefficient of 0.20 and lower wear rate of 2.73 × 10-3 mm3/m at 20 N. The worn surface of this composite has minor grooves, plows, and fewer wear particles compared to other composites.

AZ31-Mg metal matrix composite in metallurgical and testing approaches

The objective of this research is to experimentally investigate the metallurgical, mechanical, and tribological behavior of [Formula: see text], SiC, and [Formula: see text] reinforced AZ31 magnesium metal matrix composite (MMC) fabricated via powder metallurgy process. Accordingly, the mixing of the powders was carried out through ball milling operation at various times with constant speeds. The compaction of the milled powder was carried out on hydraulic press at various compaction pressures. The improvement of the wear resistance performance at 10 and 5 vol.% SiC were revealed around 12.9% and 25.8%. The fracture mechanisms of the optimal specimen resulting from the compression test were studied under SEM observation and it revealed that both ductile and brittle fractures occurred. The results from the confirmation test revealed an improvement of 2.04 g/cm3, 13%, 110.35 MPa, and 1293.399 MPa for actual density, porosity, ultimate strength, and hardness, respectively. The uniform nature of particle distribution was observed in SEM micrograph under investigation of the microstructure of the sample. The average particle size of the sample was also obtained around 809.14 nm. The proposed material is expected to be useful for various automotive and aerospace applications precisely for pistons and wings of airplane in aerospace.

Enhancement of Mechanical Behaviors and Microstructure Evolution of Nano-Nb2O5/AZ31 Composite Processed via Equal-Channel Angular Pressing (ECAP)

The automobile industry uses magnesium for load-bearing components due to its low density, durability, and ductility. This study investigated a nanocomposite containing Nb2O5 (3 and 6 wt%) nanoparticles as reinforcement with AZ31 magnesium alloy made by stir casting. A severe plastic deformation was conducted on the cast samples via equal-channel angular pressing (ECAP) after homogenization at 410 °C for 24 h and aging at 200 °C for 10 h. The microstructural distributions and mechanical properties of the magnesium metal matrix composites (MMCs) reinforced with Nb2O5 nanoparticles were investigated via ECAP. With the increase in the number of ECAP passes, the grain sizes became uniform, and the size of secondary phases reduced in the pure Nb2O5/AZ31 MMC. The grain size decreased remarkably after the ECAP process from 31.95 µm to 18.41µm due to the dynamic recrystallization during plastic deformation. The mechanical properties of hardness, ultimate tensile strength, and elongation effectively improved after each ECAP pass. The maximum values achieved for the Nb2O5/AZ31 composite subjected to ECAP were 64.12 ± 12 HV, 151.2 MPa, and 52.71%.

Friction, wear, and characterization of magnesium composite for automotive brake pad material

Magnesium metal matrix composites for lightweight brake pad applications are developed in this study. The composites are fabricated by using the powder metallurgy process. The addition of 0.5 wt.% to 2 wt.% Y2O3 (Rare Earth Oxide) used as a reinforcement to the AZ31 Mg composite is investigated. Density, hardness, and tribometer tests are carried out according to the ASTM standards. The friction and wear test of magnesium composites is tested against the grey cast iron disc. FESEM analysis shows the microstructure and morphology of worn surfaces. The elemental mapping result depicts that the elements of Mg, Al, Zn, Y, and O are uniformly distributed in the composite. X-ray diffraction analysis shows the compounds of Y2O3, MgO, ZnO, and Al2O4 are present on the worn surface of AZ31 + 2 wt.% Y2O3 composite. The outcome of the experiment reveals that increasing the proportion of yttrium oxide increases the magnesium composite's density and decreases the porosity. AZ31 + 2 wt.% Y2O3 composite exhibits the highest hardness of 122HV, a stable coefficient of friction, and a lower wear rate compared to AZ31 + 0 wt.% Y2O3 composite.

Microstructure and mechanical properties of magnesium alloy reinforced with TiB2 and B4C processed through friction stir processing

Due to its light weight, particulate magnesium metal matrix composites have become a popular choice for industrial applications in the fabrication of vehicles. There were a few practical challenges with creating magnesium-based alloy composites, such as flammability and significant shrinkage. Despite the real time fabrication limitations, researchers are being attracted in magnesium metal matrix composites that are reinforced with particulate reinforcements due their high strength to weight ratio. Friction Stir Processing is one of the most widely used processes used to produce Magnesium metal matrix composites. Because of low process temperature, it is mostly impervious to chemical reactions that are caused during conventional manufacturing processes. The present research work emphasis on the development of AZ31alloy composite by friction stir processing reinforced with TiB2 and B4C particulate reinforcements. The effect of added reinforcement in mechanical properties like tensile strength, hardness, and wear performance were observed. The addition of TiB2 helps in improving the ultimate tensile strength of the magnesium MMC. SEM observations have shown that the number of passes increased it refined the grain size. Particle sizes were also seen to be reduced in size as the increment in passes. The variation in the tensile strength was not impressive; on the other hand, the hardness of FSPed samples has increased in comparison to the base material. Samples have shown improvement in resistance to the wear rate as an increase in traverse speed and it was seen to increase that resistance to wear was increased as the passes were incremented.

Magnesium-based nanocomposites synthesized using friction stir processing: an experimental study

ABSTRACT Friction stir processing is emerging as a potential methodology for manufacturing magnesium metal matrix composites with almost no defect. In the current work, friction stir processing was utilized for the synthesis of two different magnesium metal matrix composites, i.e., AZ31B/titanium carbide and WE43/titanium carbide. The produced specimens were examined for metallurgical, mechanical, and electrical characteristics. Compared to the base alloys, microstructure analysis revealed significant refinement in grains from 42 µm to 3.5 µm, which simultaneously contributes to nearly doubled microhardness values. In addition, when compared to base metal, an enhancement up to 1.66 times, 1.78 times and 1.61 times, respectively, was recorded for nano-hardness, tensile strength, and compressive strength values. Moreover, the presence of more refined grains in the fabricated composites was also shown to reduce electrical conductivity. Lastly, after analyzing various strengthening mechanisms, it was found that the refinement of grain majorly contributes to the final strengthening of the composite material.

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.

Role of processing techniques related to Mg-MMCs for biomedical implantation: An overview

Magnesium is one of the lightest structural metals currently available, and it can replace conventional alloys in mass-saving applications while still offering superior stiffness and strength. The presence of reinforcing components inside the metallic matrix has a substantial impact on stiffness, specific strength, wear behaviour, damping behaviour, and creep qualities when compared to conventional engineering materials. Due to their superior physical and mechanical characteristics, low density, and suitability for a variety of applications, magnesium metal matrix composites are ideal materials. This paper describes how to choose an acceptable technique and its process parameters for the synthesis of magnesium-based metal matrix composites (MMCs). Additionally, it gives a general summary of how different reinforcements affect magnesium and its alloys, highlighting both their benefits and drawbacks.