Mg-based Metal Matrix Composites Research Articles

The top 100 most cited articles on magnesium alloy orthopedic implants: A bibliometric and visualized analysis

Magnesium (Mg) alloys are considered as promising bone implant materials due to their natural degradability, good biocompatibility, and good mechanical properties. Therefore, magnesium alloys have received considerable attention in the field of orthopedic implants due to their superior comprehensive properties. In this study, we analyzed the basic information of the top 100 most frequently cited articles on mg alloy orthopedic implants that met the inclusion criteria in the WoS Core Collection database, and the VosViewer software was used for web visualization and keyword analysis. Through bibliometric and visual analysis, this article systematically introduces the research status of magnesium alloy orthopedic implants, discusses the advantages of magnesium and its alloys as orthopedic implants, and explores four strategies to improve corrosion performance, including purification, alloying treatment, surface coating and Mg-based metal matrix composites (MMC). In addition, this paper revealed the future research focus in this field.

Recent trends in biodegradable magnesium matrix composite: Manufacturing techniques, applications, and future scope

There is a need for in-depth study in the area of materials and metallurgicalscience to address worldwide concerns linkedto the shortage of environmentally friendly materials. Considering the fact that magnesium (Mg) is susceptible to corrosion, there has been an increase in demandfor creating recyclable nanocomposites depending on Mg. Numerous strategies, including the fabrication of composites with appropriate organic reinforcing agents, metal alloys, or surface changes, have been implemented to solve the problems of oxidation of pure Mg. Mg, the lightweight metal ever discovered, has a lot of potential for usage in structural alloys. Mg-based Metal Matrix Composites (MMC) are the idealoptions and have so far solved the difficulties in all areas of mechanical and bio-medical purposes because of their low weight, improved rigidity, toughness, strength-to-weight proportion, and fatigueresistance. The lighter alloys as well as nanocomposites appeal to the automotive and aerospace industries and offer a substitute for heavier metals like steel, cast iron, zinc compositions, and even aluminum (Al)alloys. This report outlines all the considerable characteristics of the various fabrication methods used to developMagnesium MatrixComposite (MMCs), including stir casting technique, powder metallurgy, friction stir processing, as well as infiltration. It also contains background informationon composite materials and the different reinforcement particle used to fabricate MMCs.

A Novel Study on the Effect of Tool Offset in Friction Stir Processing for Mg-NiTi Composite

Mg-NiTi-based metal matrix composites are appropriate solutions for the two most important goals of material engineers in the present day, i.e., imparting functional behaviour and the light weighting of metallic structures. In recent years, due to its solid-state nature, the development of Mg-based metal matrix composites has largely benefited from friction stir processing. Despite the great effort of researchers in the domain of friction stir welding and processing, finding optimum process parameters for efficient material mixing and consolidation remains a rigorous and exhaustive challenge. Tool offset variation has been seen to aid the integrity and strength of friction stir welds; however, its effect upon the stir zone structure, material flow, particle distribution, and defect formation has not been investigated for friction stir processing. Therefore, the authors employed Mg as the base metal and NiTi shape memory alloy as the reinforcement to the targeted metal matrix composite. The tool offset was linearly varied by tilting the slotted length with respect to the traverse direction. Friction stir processing performed at a rotational speed of 560 rpm and traverse speed of 80 mm/min revealed crucial changes in defect morphology and area, which has been explicated with the quantified variation in tool offset from the advancing side to the retreating side. For the positive offset conditions, i.e., tool offset towards the advancing side, the shape of the tunnelling defect was chiefly convex from the outward direction. Meanwhile, for the negative offset conditions, i.e., tool offset towards the retreating side, the tunnelling defect exhibited a concave outward shape. A transition from rectangular to triangular morphology was also observed as the tool moved from an offset of 1.75 mm in the advancing side to 1.75 mm in the retreating side.

Machinability study of Al and Mg-based metal matrix composites using wire-EDM

In this investigation, a machinability study of the fabricated aluminium (Al) and magnesium (Mg) based MMCs is done using the Wire-EDM process. Initially, Al and Mg-based MMCs are fabricated with Silicon Carbide (SiC) reinforcements particles by the bottom pouring type stir casting process. After that, successful machining of both Al and Mg-based MMCs is carried out using Wire-EDM. The lowest value of machining time and kerf width for both Al/SiC and Mg/SiC MMCs are observed (0.1732 min, 0.3270 mm) and (0.1980 min, 0.2970 mm) respectively. The highest value of material removal rate 71.6651 mm3/min and 53.1313 mm3/min are achieved correspondingly for the Al and Mg-based MMCs. Overall evaluation criteria (OEC) values are calculated for all machining conditions to find out the mean effect of all process parameters simultaneously. The highest calculated OEC value of 75.00 and 84.45 are observed intended for Al/SiC and Mg/SiC respectively.

Recent Developments in Magnesium Metal-Matrix Composites for Biomedical Applications: A Review.

Recently, there is a growing interest in developing magnesium (Mg) based degradable biomaterial. Although corrosion is a concern for Mg, other physical properties, such as low density and Young's modulus, combined with good biocompatibility, lead to significant research and development in this area. To address the issues of corrosion and low yield strength of pure Mg, several approaches have been adopted, such as, composite preparation with suitable bioactive reinforcements, alloying, or surface modifications. This review specifically focuses on recent developments in Mg-based metal matrix composites (MMCs) for biomedical applications. Much effort has gone into finding suitable bioactive, bioresorbable reinforcements and processing techniques that can improve upon existing materials. In summary, this review provides a comprehensive overview of existing Mg-based composite preparation and their mechanical and corrosion properties and biological responses and future perspectives on the development of Mg-based composite biomaterials.

Application of Environmentally-friendly Cooling/Lubrication Strategies for Turning Magnesium/SiC MMCs

The material having high strength to weight ratio is constantly in high demand for automotive industries to increase fuel efficiency. With this view, AZ91/5SiC (an Mg-based Particulate Metal Matrix Composites (PMMCs)) is fabricated using an in-house developed stir casting setup and characterized through Field Emission Scanning Electron Microscopy (FESEM) with Energy-Dispersive X-ray Spectroscopy (EDS) analysis. However, the machinability of PMMCs is found to be lower due to the existence of harder ceramic constituents and appropriate cutting fluid strategies are required to follow to combat this situation. But limited studies are available identifying the impact of recently developed sustainable cooling and lubrication techniques on machining performance when PMMCs is turned. To fill this bridge, customized setups of minimum quantity lubrication (MQL), cryogenic and CryoMQL machining with LN2 have been developed to provide eco-friendly cutting fluid approaches to turn AZ91/5SiC. The cutting force, energy consumption, surface roughness (Ra) and chip breakability index (Cin) have been analyzed for MQL, cryogenic and CryoMQL techniques with variation in process parameters. By considering the average value of all turning tests, 64.65% and 40.39%; and 11.49% and 7.13% higher value of cutting force and energy consumption is found correspondingly for cryogenic and CryoMQL machining respectively as compared to MQL technique respectively. Overall, 25.59% and 18.35% lower values of Ra have been observed for CryoMQL technique as compared with MQL and cryogenic machining respectively. The powder type chips with comparable higher values of Cin have been found in all three cooling and lubrication techniques.

Micro-drilling of Mg-based MMCs reinforced with SiO2 nanoparticles: An experimental approach

Mg-based metal matrix composites reinforced with nanoparticles are promising biomaterials due to their biocompatibility and high hardness and because they are local and systemic toxicity free. Nano-metal matrix composites are considered to be hard-to-machine materials due to the high strength and high abrasiveness of the reinforcing nanoparticles. In this article, the micro-drilling mechanisms of Mg-based metal matrix composites reinforced with different volume fraction of SiO2 nanoparticles (0.5, 1.0, 1.5, 2.0 vol.%) were investigated experimentally. Results obtained were also compared with pure Mg. First, it was found that the volume fraction and drilling parameters played an important role in the chip formation mechanism. Second, the influence of drilling parameters on hole surface morphology and cutting force were studied, in which both the rotation speed and feedrate affected the surface morphology, and the main factor affecting cutting force was found to be the feedrate. Furthermore, the formation of burrs was investigated. The height of the burr could be reduced by using small feedrate and low rotation speed. Finally, the size effect of micro-drilling was studied. The variation of surface roughness and cutting force of pure Mg and Mg-based metal matrix composites had three changing trends with the uncut chip thickness. The minimum chip thickness of Mg/SiO2 metal matrix composites was determined to be 1.1 μm.

The role of in-situ ceramic reinforcements on microstructure evolution and mechanical properties on developed hybrid Mg-MMCs

In-situ generation of ceramic reinforcements during the manufacturing of metal matrix composites (MMCs) have wide advantages ranging from better dispersion, generation of nanoceramics to increased compatibility with matrix. The present work aims to explore the effect of precursor concentration on the in-situ generation of CeO2 and MgO particles in Mg-based MMC. The contribution of different strengthening mechanisms is also explored. Optical microscopy, Scanning electron microscope (SEM), Energy dispersive spectroscopy (EDS) analysis, and X-ray diffraction (XRD) of the developed MMCs lead to categorization of particles and features into cauliflower structure, agglomerated nanoceramics, composite ceramic particles (CCP), nanoceramics, nanopores and intermetallic. Vickers hardness tests, compression tests, and scratch tests are carried out to evaluate the mechanical response of MMCs. The compression fractured surfaces are analyzed using SEM. Preliminary wear response is evaluated using a 3-D optical profilometer to evaluate the scratched surfaces. The effect of particle size and concentration on various strengthening mechanisms is evaluated. It is possible to manipulate the mechanical properties through controlling the in-situ reinforcement type and distribution, which is also further possible, as reported here.

Experimental investigation on micro-drilling properties of Mg-based MMCs reinforced with HAP nanoparticles

Mg-based metal matrix composites (MMCs) reinforced with Hydroxyapatite (Ca10(PO4)6(OH)2, HAP) nanoparticles have been studied as bone substitute materials because of their excellent biocompatibility and biological activity. In this paper, Mg/HAP MMCs with different HAP contents (0.5, 1.0 wt%) were selected and the micro-drilling properties were revealed. Firstly, the chip of MMCs was analyzed. Secondly, the surface roughness of Mg/HAP MMCs under different cutting parameters was studied. The results showed that the surface roughness decreases with the increasing of feedrate and decreases with the increasing of spindle speed, which are contrary to pure Mg. Furthermore, the shapes of burr are all classified as uniform burr, and the burr height increased with the increase of spindle speed and feed. Finally, the size effect of micro-drilling was studied. The minimum cutting thickness per tooth of Mg/HAP MMCs was determined to be 1.0 μm.

Mechanical Properties and Corrosion Behavior of WZ73 Mg Alloy/SiCp Composite Fabricated by Stir Casting Method

Low strength, which limits the industrial applications of Mg alloys, can be improved by forming Mg-based metal matrix composites (MMC) reinforced with ceramic particles. In this study, a Mg-based MMC was synthesized by introducing SiC particles into a WZ73 Mg alloy using the stir casting method. The effects of the SiC particles on the mechanical properties and corrosion behavior of WZ73 alloys were studied. The results showed that an addition of 1.5 vol % of SiC enhanced the strength of a WZ73 alloy but reduced the corrosion resistance. A further increase of SiC to 2.5 vol % had no effects on strength and corrosion behavior, which was attributed to the agglomeration of SiC particles. A microstructural analysis indicated that the addition of SiC did not alter the morphology and distribution of the secondary phase in the WZ73 alloy. Thus, the improved strength was attributed to the reinforcement of SiC and the refinement of the Mg grain, while the degraded corrosion resistance was the result of the grain refinement of Mg and the presence of the Mg/SiC interface in the vicinity of the secondary phase, which breaks the continuity of the Mg matrix and results in a higher corrosion rate.

Improving hydrogen storage performance of AZ31 Mg alloy by equal channel angular pressing and additives

In this study, commercial AZ31 Mg alloys were processed by equal channel angular pressing (ECAP) to study the effects of processing route and numbers of passes on hydrogen storage properties of AZ31 alloys. Furthermore, Mg-based metal matrix composites (MMCs) were fabricated by gravimetric casting of AZ31 alloy, activated carbon and Ni to investigate the effect of additives on hydrogen storage properties. The results indicated that kinetics of hydrogen uptake increased with the increasing number of pass. AZ31 processed by ECAP route Bc with 8 passes had hydrogen capacity of 7.0 wt%, and demonstrated the highest grain refinement and the fastest hydrogen absorption kinetics. With the addition of 5 wt% of activated carbon and 0.5 wt% Ni, the hydrogen sorption kinetics of MMCs was enhanced and was comparable to that of the AZ31 processed by ECAP with 8 passes; however, in exchange for the improved kinetics, the hydrogen storage capacity was lowered to 6.3 wt%. To enhance hydrogen absorption kinetics, adding catalysts in the casting process could be more efficient than post-casting ECAP treatment if saving processing time is the priority.

Prediction of corrosion susceptibilities of Al-based metal matrix composites reinforced with SiC particles using artificial neural network

In this theoretical study, the prediction of the corrosion resistance of Al–Si–Mg-based metal matrix composites reinforced with SiC particles has been studied, using an artificial neural network. Four input vectors were used in the construction of the proposed network; namely, volume fraction of SiC reinforcement, aging time of the composites, environmental conditions, and potential. Current was used as the one output in the proposed network. Test results indicate that the proposed network can be used efficiently for the prediction of the corrosion resistance of Al–Si–Mg-based metal matrix composites reinforced with SiC particles, and the methodology is suitable for engineers to study the corrosion of metal matrix composites. In addition, a few forecasts regarding the polarization response for different SiC volume fractions and aging conditions have also been generated without using any experimental data.

On the corrosion behaviour of newly developed biodegradable Mg-based metal matrix composites produced by in situ reaction

Biodegradable Mg-based metal matrix composite (Mg-MMC) reinforced by MgO ceramics and Mg–Zn intermetallics were prepared by in situ reaction using a powder mixture of pure magnesium and 20 wt% ZnO as raw materials. The corrosion behaviour of Mg-MMC was evaluated by electrochemical measurements and immersion tests in Hanks’ solution. Results show that the newly developed Mg-MMC is composed of α-Mg matrix and uniformly distributed MgO ceramic and Mg–Zn intermetallics in matrix as reinforcements. The Mg-MMC possesses a corrosion behaviour comparable to pure magnesium and exhibits enhanced improvement in mechanical properties and corrosion resistance.

Particle Size Effects of Silicon Carbide on Wear Behavior of SiCp-Reinforced Magnesium Matrix Composites

This article investigated the particle size effect of micro-sized SiC on the tribological behavior of SiCp-reinforced AZ91D Mg-based metal–matrix composites (MMCs). The Mg MMCs were prepared by the melt-stirring technique for wear tests. The hardness and coefficient of friction of Mg MMCs increases as particle size of SiC particle in MMCs increases, except for the hardness tendency at the region between particle size of 11 and 15 μm. The SiCp/AZ91D MMCs exhibit superior wear resistance under lower and moderate sliding condition. However, the effects of the SiC particle reinforcements on wear resistance are not as conclusive under severe sliding condition, since the matrix of MMCs were softened at elevated temperature under such a severe condition.

Volume Fraction Effects of Silicon Carbide on the Wear Behavior of SiC<sub>p</sub>-Reinforced Magnesium Matrix Composites

This paper investigated the volume fraction effect of micro-sized SiC on the tribological behavior of SiCp reinforced AZ91D Mg-based metal-matrix composites (MMCs). The Mg MMCs were prepared by the melt-stirring technique for wear tests. The hardness and coefficient of friction of Mg MMCs increase as increasing volume fraction of SiC particle in MMCs. The SiCp/AZ91D MMCs exhibit superior wear resistance under lower and moderate sliding condition. However, the effects of the SiC particle reinforcements on wear resistance are not as conclusive under severe sliding condition (50N-1500 rpm for all vol.% of MMCs, 50N-1000rpm for 3 vol. % MMCs), since the matrix of MMCs were softened at elevated temperature under such severe condition. However, the incorporation of SiC particles could enhance the wear resistance of AZ91D matrix alloy for most of the sliding conditions.

Corrosion behavior of SiC reinforced magnesium composites

The corrosion behavior of two SiC reinforced Mg-based metal matrix composites, Mg–6SiC and Mg–16SiC (in volume percent), has been studied in freely aerated 1 M NaCl solution and compared with that of pure Mg. The presence of SiC particles deteriorated the corrosion resistance of magnesium. Corrosion resistance decreased with increasing SiC volume fraction. The galvanic corrosion current density between pure SiC and pure Mg has been experimentally measured using zero resistance ammeter technique and theoretically determined using mixed potential theory. Galvanic corrosion between Mg matrix and SiC reinforcement in the composites did not contribute significantly to the overall corrosion rate. Electrochemical impedance spectroscopy indicated that the higher corrosion rates for the composites could be related to the defective nature of surface film.

Corrosion Behavior of an Artificially Aged (T6) Al–Si–Mg-based Metal Matrix Composite

The influence of age hardening on the corrosion behavior of Al–Si–Mg-based metal matrix composites (MMCs) has been investigated in aerated and deaerated 3.5 wt% aqueous NaCl solutions. Silicon carbide particle (SiCp reinforced composites consisting of 10 and 20 vol% SiCp are produced by the compocasting technique. After the extrusion process, the composites are artificially aged (T6). The corrosion resistances of the aged composites are analyzed by measuring the cyclic potentiodynamic polarization. The surface morphology of the composites before and after the corrosion tests are determined by using metallographic methods and scanning electron microscopy (SEM). In addition, the X-ray diffraction technique (XRD) has been used to determine the phases that occur at the matrix–reinforcement interface. The results demonstrate that the Epit values of unreinforced matrix alloy and composites increase negatively with increasing aging time. It is also observed that corrosion preferentially starts at the interface of Al–Mg2Si and Al–SiCp.

Acoustic Emission and Dilatometry for Non-Destructive Characterisation of Microstructural Changes in Mg Based Metal Matrix Composites Submitted to Thermal Cycling

Many Mg-based metal matrix composites (MMCs) have been developed and manufactured during the last decade as prospective light high-performance constructional materials. When a MMC is submitted to temperature changes (cooling down from the temperature of fabrication, cyclic temperature changes during operation of structural parts) thermal stresses arise at the interfaces owing to a considerable mismatch of the thermal expansion coefficient of the matrix and that of the reinforcement. Even slight temperature changes may produce thermal stresses which exceed the matrix yield stress, consequently, generating new dislocations at the interfaces causing microstructural changes and plastic deformation of the matrix. Long-term exposure may also result in fatigue damage. It is noteworthy that the effect of temperature variations is similar to creep under non-stationary loading conditions. Acoustic emission (AE) has been observed during thermal cycling of Mg based MMCs. Since dislocation motion and microstructural damage are generally accepted to produce AE, it is possible by AE measurements to identify and to characterize the microstructural changes and to correlate them with temperature or other parameters. The dilatometry technique enables the degree of matrix plastic deformation which superposing the thermal expansion to be determined by measuring the shape changes during testing. The combination of bothmore » methods yields non-destructively, at any instant of the test, information on the structure and operating processes over the entire volume of the specimen. This can also provide valuable information for subsequent investigations by microscopy or internal friction. The object of this paper is to report on the recently developed, combined AE and dilatometry technique and its application in a structural evolution in Mg-based MMCs subjected to thermal cycling.« less