Processing Of Metal Matrix Composites Research Articles

On understanding the cutting mechanism of SiCp/Al composites during ultrasonic elliptical vibration-assisted machining

SiCp/Al composites play a significant role in achieving equipment lightweight, but its mechanical properties weaken the machinability. Ultrasonic elliptical vibration-assisted machining (UEVM) is a potential way to improve the machinability of difficult-to-cut materials, provides an efficient and precise solution for SiCp/Al composites in industrial manufacturing. However, the removal mechanism of SiCp/Al composites during UEVM and the effective guidance for practical machining are rarely investigated. In this paper, the cutting mechanism of SiCp/Al during UEVM is analyzed through theoretical analysis, finite element (FE) simulation and systematic experiments. Specifically, a multi-phase 2D microscopic FE simulation model is implemented and verified through systematically scratching tests. The research results indicate that particle stress distribution is influenced by variable tool-particle relative position during UEVM, promoting particle fracture and forming high-density zone of broken particles. Segmented chips with shorter length and greater curvature are the main form during UEVM, and dense layered structure appears on free surface of chips. Surface defects include cavities, crushing particles and scratches, while subsurface damage is dominated by pits and crack invasion. In addition, removal rate affects the surface formation, especially under very low scratching speed. Higher scratching speed weakens the ability of particle crushing under vibration effect, which is not helpful for improving surface integrity. Therefore, a reasonable cutting speed of 200 mm/min should be set during UEVM. This paper brings in a deeply understanding on cutting mechanisms of SiCp/Al composites, provides a theoretical guidance for the design and optimization of the vibration assisted processing of metal matrix composite.

Development of pressure infiltration preparation of metal matrix composites

<p>This paper summarizes the process of metal matrix composites from pressure infiltration preparation to pressure ultrasonic assisted infiltration to pressure solvent assisted infiltration. The advantages of preparing metal matrix composites by pressure infiltration alone are low cost and convenient for mass production. However, the equipment and process requirements are too high, and the quality of composite materials can not be guaranteed. Because of the high pressure of ultrasound, ultrasonic infiltration has become an auxiliary physical method for the preparation of metal matrix composites by pressure infiltration. But this method tends to damage the fibers. Therefore, the fibers need to be coated. The coating on the fiber surface is divided into metal coating and non-metal coating. Some people mixed SiC particles or whiskers in continuous carbon fibers to prepare aluminum alloy composite materials, forming a hybrid assisted infiltration method. Later, people began to pay attention to the flux-assisted role of pressure infiltration. Therefore, solvent-assisted infiltration of fiber-reinforced metal matrix composites has become an important research field.</p>

Overcoming Challenges in the Powder Metallurgy Process of Metal Matrix Composites

Overcoming Challenges in the Powder Metallurgy Process of Metal Matrix Composites

Process study for directed energy deposition of 316L stainless steel with TiB2 metal matrix composites

In addition to laser powder bed fusion, directed energy deposition (DED) is also gaining interest as an effective metal additive manufacturing technique. Due to its system configuration, it is more efficient and flexible for materials development. Therefore, it can be used for processing of metal matrix composites (MMCs) through the use of powder mixture as feedstock. 316L stainless steel has high corrosion resistance, biocompatibility, and ductility. Several studies have shown the feasibility of using DED to process 316L stainless steel. The material properties of 316L stainless steel can be improved using reinforcement particles such as TiB2 to form MMCs. In this study, the effects of process parameters on microstructure and mechanical properties of 316L stainless steel reinforced with TiB2 (316L/TiB2) MMC were studied. The process parameters, including laser power, scanning speed, and hopper speed, were varied and analyzed using Taguchi L9 array. It was found that the process parameters have insignificant effect on the bulk density of the samples produced. Through this study, it is also found that tumble mixing was not suitable for the powder feedstock preparation for MMCs to be processed by DED. The microstructure of DED 316L/TiB2 MMC samples consists of columnar and equiaxed grains. Columnar grains were located within the layers while equiaxed grains were located at the interlayer zones. Fine sub-grains were also observed within these grains and their boundaries were enriched with molybdenum and chromium segregations. Precipitates containing titanium were also observed to segregate at the sub-grain boundaries. Finally, the Vickers microhardness of the DED 316L/TiB2 MMC was found to be similar to pure 316L stainless steel produced by DED.

In-situ metal matrix composites development for additive manufacturing: a perspective

This paper presents an overview on some ceramic materials capable of achieving in-situ reinforcements in Al/Al-alloy metal matrix composites (MMCs) during laser processing. It also presents perspective on further exploitation of the in-situ reinforcement capabilities for high quality MMCs feedstock material development. The approach utilized in writing this paper encompasses the review of relevant literature on additive manufacturing (AM) of MMCs. It is widely accepted that the in-situ reinforcement approach has proven to be more advantageous than the ex-situ approach. Though there are still some challenges like the formation of detremental phases and the evaporation of low melting temperature elements, the in-situ reinforcement approach can be used to tailor design composite powder feedstock materials for the AM of MMCs. The preprocessing or tailor-designing in-situ metal matrix composite powder before laser melting into desired components holds more promises for metal additive manufacturing. The need for the development of MMCs powder feedstock that can be directly fabricated using suitable AM technique without prior powder processing like blending or mechanical alloying has not yet been addressed Therefore, having a pre-processed in-situ reinforced MMC feedstock powder can encourage easy fabrication of MMC and other advantages of AM technologies powder recycling. The idea explained in this article is relevant to materials development for AM processing of metal matrix composite. This paper has pointed out future trends for MMCs materials feedstock powder development and new ideas for further exploitation of MMCs and AM technologies. The advantages of tailor-designing composite powders other than merely mixing them has been emphasized.

Correction to: Experimental Investigation of In-Homogeneity in Particle Distribution during the processing of Metal Matrix Composites

Correction to: Experimental Investigation of In-Homogeneity in Particle Distribution during the processing of Metal Matrix Composites

Surface energy contributions to the work of infiltration in metal matrix composite processing

The work needed to mechanically drive molten metal into a porous solid preform when producing a composite material by infiltration can significantly exceed the energy change required for thermodynamically reversible infiltration. We measure, by quantitative metallographic analysis of partially infiltrated, particle- or fiber-based non-metallic preforms, the evolution with saturation of the three interfaces present during the process. Results show that irreversible energy losses in the infiltration of alumina preforms by molten copper, aluminium or aluminium-tin alloy cannot be ascribed to the creation of liquid meniscus surface area at intermediate metal saturation. This result agrees with similar observations in soil science and gives experimental confirmation of predictions from a recent simulation of capillarity-dominated metal infiltration [Acta Mater., vol. 210, 2021, 116831].

Surface energy contributions to the work of infiltration in metal matrix composite processing

Surface energy contributions to the work of infiltration in metal matrix composite processing

Analyzing the Effect of Particle Shape on Deformation Mechanism during Cutting Simulation of SiC P/Al Composites.

To analyze the effect of particle shape on deformational behavior in the cutting simulation process for metal matrix composites (MMCs), two 2D mesoscopic-based finite element (FE) models reinforced with randomly distributed circular and irregular polygonal particles were developed. Different material properties (metal matrix phase, particle reinforced phase) and the properties of the particle–matrix interface were comprehensively considered in the proposed FE model. Systematic cutting experiments were conducted to compare the differences between two modeling approaches with respect to particle fracture, chip formation, cutting force and surface integrity. The results show that the irregular polygonal particle model is closer to the microstructure of MMCs, and is better able to reflect the deformation behavior of particles. The simulation model with irregular polygonal particles is even able to capture more details of the impact caused by particles, reflecting variations in the cutting force in the actual cutting process. The initiation and propagation of microcracks is mainly determined on the basis of particle geometry and further affects chip formation. Both models are able to correctly reflect surface defects, but the irregular polygonal particle model provides a more comprehensive prediction for the subsurface damage of MMCs.

The Comprehensive Study on the Classical Constitutive Models in Predicting the Hot Deformation Behavior of Al5083-SiC Metal Matrix Composite

The main goal of this research is to study the hot deformation process of metal-matrix composites and investigate the possibility of using classical constitutive models to calculate the flow stress of such composites during the hot deformation process. A 5083 aluminum-based metal composite reinforced with 9 wt.% of 37 micron SiC particles, and made by stir-casting method, was used for the study. Standard and improved Johnson-Cook model, Arrhenius and Zerilli-Armstrong models in the temperature range of 673-823 K, and strain rates of 0.001-1 s-1 were extracted and their accuracy was studied. Based on the results, classical models used to predict the hot deformation behavior of metal alloys can also be used to predict the behavior of aluminum-matrix composites with reasonable accuracy depending on the type of model. The hot deformation activation energy Q for the composite based on the hyperbolic-sine law Arrhenius equation, is 265.5 kJ/mol. The strain-compensated Arrhenius model was the best model to predict the behavior of the composite with the error less than 7% and can reasonably predict the trend of changing the flow stress even at high temperatures with the correlation factor of 0.989.

Real-time visualization of particle evolution during reactive flux-assisted processing of aluminum melts

A multi-modal, multi-scale correlative tomography investigation of Al-TiC metal matrix composites processed via flux-assisted reaction synthesis is reported. Synchrotron X-ray microradiography is utilized to visualize the reaction and particle evolution in real-time. Changes in particle diameter and areal number density suggest that the process is nucleation- rather than growth-dominated. At 950 °C, the bulk of the reaction takes place in a relatively short time span of less than 600 s. The microstructure is imaged at higher resolution in 2D (scanning electron microscopy) and 3D (synchrotron X-ray nanotomography), revealing the formation of carbide particles with a hexagonal platelet morphology. We propose that the morphology arises due to the incorporation of Si impurities during the experiment. It is expected that the correlative tomography workflow and analysis may guide future metal matrix composite (MMC) processing strategies.

Effect of process parameters on material removal rate in magnetic abrasive flow machining of Al/SiC/B4C metal matrix composites

In the recent times, the necessity for magnetic abrasive flow machining (MAFM) process in the industry arises as it is superior to conventional machining processes. MAFM is used to obtain high surface finishing and materials removal rate for the cylindrical, complex and intricate profiles. In this paper, the effect of process parameters has been studied on the material removal rate in MAFM process of metal matrix composites of Al/SiC/B4C prepared by stir casting process. The process parameters are magnetic field, extrusion pressure, no. of cycles, mesh size of abrasives, workpiece material and concentration of abrasives.Taguchi design of experiments has been used for design of experiments and the analysis of variance technique has been used to check the significance level of each input parameter. The results show that the intensity of magnetic field has a dominant effect on the material removal rate.

Experimental Investigation of In-homogeneity in Particle Distribution During the Processing of Metal Matrix Composites

Particle reinforced metal matrix composites are skilled to fulfill the late needs of cutting edge designing applications, because of its tunable mechanical properties. Stir casting is one of the unmistakable and affordable strategies for preparing of particle reinforced metal matrix composites. However, complete investigation and evaluation of the vortex pressure and the homogenous distribution of particles are still an obstacle for the research community. In this method, vortex pressure and flow pattern are the important factors for the dispersion of particles in the liquid metal. Effectual flow pattern and vortex pressure can be attained by optimizing stir casting parameters such as volume concentration (5%, 10%), stirrer blade angle (45º, 90º), impeller position (20%, 40%) from the base, viscosity of Al melt (1.04 mPa-s, 1.24 mPa-s) and holding time (10 minutes, 15 minutes). In this research, computational fluid dynamics has been used to find the vortex pressure, which influences the particle distribution. A new photographic technique was implemented to find out the flow pattern of the reinforcement particles and the stir casting parameters are optimized using Taguchi method. Optimized parameters have been utilized for the production of PRMMCs. In addition, micro structural image and hardness test confirm the uniform particle distribution of the reinforcement particles. From the outcome of various experimentations, 10 minutes holding time of the stirrer blade with 45º angle which was kept 40% from the base and the viscosity of the Al melt (1.04 mPa-s) with 10% volume fraction of SiC particles shows effective flow pattern and optimum vortex pressure with homogenous distribution of SiC particles.

Solidification Processing of Cast Metal Matrix Composites Over the Last 50 Years and Opportunities for the Future

This paper reviews the progress of solidification processing of cast metal matrix composites over 50 years since their original discovery, which was first published in 1969. Current use of metal matrix composite components in automotives, railways, space, computer hardware, and recreational equipment are presented. Some cast metal matrix composites which are discussed include aluminum reinforced with graphite, silicon carbide, alumina, and fly ash. Several critical issues in solidification processing of metal matrix composites, including nucleation, growth, the effects of reinforcements of fluidity, and the thermo-physical properties of the melts on micro-segregation, and particle pushing or engulfment during solidification of the are discussed. Current and future directions and challenges in solidification processing of cast metal matrix composites are presented, including the synthesis of self-lubricating, self-healing, and self-cleaning composites using solidification processing.

The effect of thermal mismatch on the thermal conductance of Al/SiC and Cu/diamond composites

Thermal mismatch at the interface is inevitable in the manufacturing process of metal matrix composites. The relationship between strain and thermal conductivity of metal is obtained. The plastic strain region caused by thermal mismatch and its effect on thermal conductance of Al/SiC and Cu/diamond are acquired and discussed using the finite element method. It is found that the average strain is independent of particle size and proportional to the ratio of particle radius to distance. The strain will affect the thermal conductivity of composites in two ways. One is to decrease the effective thermal conductivity of matrix, which is more significant for the Al/SiC system than the Cu/diamond system, but it has a relatively small impact on the thermal conductivity of composites. The other is to reduce the interfacial thermal conductance (ITC) by weakening interfacial bonding and scattering phonon transport, making the effective thermal conductivity of reinforcement and thermal conductivity of composites decrease, which has a bigger impact on composites with high thermal conductance reinforcements. The results also show that there is an increase of thermal conductivity of composites with ITC in a specific region determined by particle size, and the composite reinforced with large particles has a higher thermal conductivity at low ITC because of the low density of interface. Our work is important for understanding the effect of thermal mismatch on thermal conductance of metal matrix composites and provides a way to bridge the relationship between mechanical behavior and physical properties.

Selective laser melting of aluminium metal-matrix composites and the challenges

Metal matrix composites based on aluminium metal matrices offer material solutions for high performance and low weight applications. The reinforcement filler materials in the form of continuous or discontinuous fibres, whiskers or particulates allow for the properties to be tailored to suit to different application demands. Several grades of aluminium matrix composites manufactured by different means are currently in use for high-tech structural and functional applications including aerospace, defence, automotive, and thermal management areas, as well as in sport’s needs. The growth in the additive manufacturing technologies made possible a plethora of new opportunities in terms of controlling the dispersion of the filler particles, which is in particular a major constraint with the traditional bulk manufacturing methods. While there are specific benefits drawn from the point-by-point consolidation mechanics of additive processes such as selective laser melting, certain drawbacks are also hindering the widespread application in aluminium metal matrix composite processing. Practical difficulties associated with the presence of continuous or discontinuous fibres, whiskers and other particulates and the unique microstructures resulting from the typical material consolidation mechanics are specific examples. The state-of-the art of applying selective laser melting to process aluminium metal matrix composites will be reviewed in the current paper, with specific emphasis paid to in-situ arrangement of the fillers and the material, process, structure, and property relationships.

Sustainability in Production and Selection of Reinforcement particles in Aluminium Alloy Metal Matrix Composites: A Review

This paper reviews relevant literature in the area of incorporating sustainable materials into the material selection process of metal matrix composites (MMCs) production. Agricultural and industrial waste materials used as reinforcements in MMCs have been reviewed to highlight the need for establishing a lean production process. The reviewed investigations have recorded improvements in both the microstructure, density and mechanical properties such as hardness, strength, tensile, and impact strength of the resulting MMC. The reviewed literature highlights stir casting as the most used method of producing aluminium and magnesium-based matrix composites due to its relatively low cost, simplicity, and efficiency. Based on the results of various studies, it is highly recommended that the use of these sustainable materials as reinforcements in MMCs possess the necessary properties to be used in engineering industrial applications.

Improvement of Mechanical and Fatigue Properties for Aluminum Alloy 7049 By Using Nano Composites Technique

The aim of present work is to improve mechanical and fatigue properties for Aluminum alloy7049 by using Nano composites technique. The ZrO2 with an average grain diameter of 30-40 nm, was selected as Nano particles, to reinforce Aluminum alloy7049 with different percentage as, 2, 4, 6 and 7 %. The Stir casting method was used to fabricate the Nano composites materials due to economical route for improvement and processing of metal matrix composites. The experimental results were shown that the adding of zirconium oxide (ZrO2) as reinforced material leads to improve mechanical properties. The best percentage of improvement of mechanical properties of 7049 AA was with 4% wt. of ZrO2 about (7.76% ) for ultimate tensile stress UTS, (9.62% ) for yield stress YS and (9.92%) for hardness HB than other of adding of 2, 6 and 7% of ZrO2. Also the results shown that the fatigue strength of 7049 AA with 4 % ZrO2 nanoparticles is higher than that of 7049 AA under constant loading 9.86% at 108 cycles as well as the fatigue life factor (IFLF %) at different amplitude stress 400, 350, 300 and 250 MPa was improvement in range 66, 115, 63 and 107% respectively.

Mechanical Alloying and Electrical Current-Assisted Sintering Adopted for In Situ Ti-TiB Metal Matrix Composite Processing.

In this work, mechanical alloying and electrical current-assisted sintering was adopted for in situ metal matrix composite material processing. Applied at the initial powder stage, mechanical alloying enables a homogeneous distribution of the starting elements in the proposed precursor powder blends. The accompanying precursor preparation and the structurally confirmed size reduction allow obtainment of a nanoscale range for the objects to be sintered. The nano precursors aggregated in the micro-sized particle objects, subjected to electrical current-assisted sintering, characterize the metal matrix composite sinters with high uniformity, proper densification, and compaction response, as well as maintaining a nanoscale whose occurrence was confirmed by the appearance of the highly dispersed reinforcement phase in the examined Ti-TiB material example. The structural analysis of the sinters confirms the metal matrix composite arrangement and provides an additional quantitive data overview for the comparison of the processing conditions. The mechanical alloying examined in this work and the electrical current-assisted sintering approach allow in situ metal matrix composite structures to create their properties by careful control of the processing steps.

Numerical Modeling of Fiber-Reinforced Metal Matrix Composite Processing by the Liquid Route: Literature Contribution

One of the technologies used to produce metal matrix composites (MMCs) is liquid route processing. One solution is to inject a liquid metal under pressure or at constant rate through a fibrous preform. This foundry technique overcomes the problem of the wettability of ceramic fibers by liquid metal. The liquid route can also be used to produce semiproducts by coating a filament with a molten metal. These processes involve physical phenomena combined with mass and heat transfer and phase change. The phase change phenomena related to solidification and also to the melting of the metal during the process notably result in modifications to the permeability of porous media, in gaps in impregnation, in the appearance of defects (porosities), and in segregation in the final product. In this article, we provide a state-of-the-art review of numerical models and simulation developed to study these physical phenomena involved in MMC processing by the liquid route.