Surface Metal Matrix Composites Research Articles

The Use of Ashes in Surface Metal Matrix Composites Produced by Friction Stir Processing

The article presents an assessment of the possibility of using ashes from the combustion of coal and biomass as a reinforcing phase in metal matrix composites. The composite surface layer was produced by means of the FSP (friction stir processing) method, using an original hole solution with a shifted working zone of the pin. The composite matrix was AA7075 alloy. The obtained composite was subjected to microscopic observations, tribological tests, and hardness measurements. The microscopic examinations revealed favorable changes in the microstructure, in particular, strong refinement of the grains, uniform distribution of the reinforcing phase, and good bonding of the particles of this phase with the matrix material. Changes in the microstructure resulted in a significant increase in the hardness (from 36 to 41% depending on the type of reinforcing phase) and wear resistance (from 24.1 to 32.9%), despite partial dissolution of the intermetallic phases. It was found that the effect of strengthening the matrix and the uniformity of the distribution of the reinforcing phase depend on the physicochemical properties of the used powders, especially on the shape and size of the particles. The research shows that the use of ashes as a reinforcing phase in composites is fully justified.

Friction Stirs Processing - State of The Art Process to Fabricate Metal Matrix Composites

Friction stir processing(FSP) is the solid state method to fabricate the surface metal matrix composites(MMC). This process has been derived from the concept of Friction stir welding. As this process is performed in solid state, many defects related to phase transformation can be avoided. As this process is done below the melting point temperature of metal or alloy, it is easier to control the process. Machine variables (tool rotational speed, tool traverse speed, tool tilt angle etc.), tool design variables (diameter, profile and height of probe and shoulder of the FSP tool), and material properties are the main process variables to perform FSP in order to fabricate Metal matrix composite. In addition to these variables number of passes, tool traverse patterns, reinforcement particles’ content and its’ types also can be considered as process variables. Tribological properties’ comparison can be done between alloy and MMC fabricated by FSP for different combinations of process parameters. Microstructural study also can be carried out in order to see the effects of above process parameters. In this paper the above aspects are summarized and performance assessment done by various researchers has been covered.

Tribological and corrosion behaviour of Al-Mg-CeO2 metal matrix surface composites

In this work, multiple-passes of friction stir processing (FSP) technique was utilized to fabricate Al-Mg-CeO2 surface composites (SCs). Microstructural studies revealed that 5-pass FSP showed a better dispersion of CeO2 nano-particles and enhanced grain refinement compared to 1-pass FSP. The results indicated that the Al-Mg-CeO2 SCs exhibit enhanced tribological characteristics viz; load bearing capacity, improved resistance to wear (34.48% decreased wear rate in 5-pass SCs) and corrosion resistance in respect to the non-reinforced Al-Mg matrix. The analysis of mechanical, tribological, and corrosion behaviour strongly correlates with microstructural evolution.

Investigating the tribological characteristics of copper surface composites reinforced with high entropy alloy (AlCoCrCuFe) through friction stir processing

The present investigation focuses on the fabrication of Copper-High Entropy Alloy (HEA) surface Metal Matrix Composite (MMC) using the solid-state Friction Stir Process (FSP) and the characterization of wear characteristics. Higher hardness values at the level of 770HV were the cornerstone in its selection, in addition to identifying several appropriate considerations for combining the AlCoCrCuFe HEA in Cu-HEA surface MMCs. Because of the combination of FSP and HEA, the produced composite had a fine microstructure and increased hardness. The wear test is carried out using pin-on-disc equipment for all conceivable parameter combinations to thoroughly analyze wear qualities, with velocity, load, as well as sliding distance chosen as input parameters. The wear rate decreases dramatically with HEA additions and rises with sliding velocity, load, and sliding distance. The impact of HEA addition on the Coefficient of Friction (CoF) during a dry sliding wear test is opposed to its influence on wear rate. The wear parameters such as load, sliding speed, and sliding distance possess a positive correlation with the wear rate and a negative correlation with a coefficient of friction. The applied load has a severe effect on wear rate and CoF when compared to other wear parameters considered. Scanning Electron Microscope (SEM) micrographs of the worn surface were utilized to analyze the wear process, which clearly showed that the copper’s wear resistance improved with the addition of HEA.

Author Correction: Recent Advances in Magnesium-Based Metal Matrix Surface Composites Developed via Friction Stir Processing Route—An Overview

Author Correction: Recent Advances in Magnesium-Based Metal Matrix Surface Composites Developed via Friction Stir Processing Route—An Overview

Aluminium-Based Dissimilar Alloys Surface Composites Reinforced with Functional Microparticles Produced by Upward Friction Stir Processing

Surface metal matrix composites offer an excellent solution for applications where surface properties play a crucial role in components’ performance and durability, such as greater corrosion resistance, better wear resistance, and high formability. Solid-state processing techniques, such as friction surfacing and friction stir welding/processing, offer several advantages over conventional liquid-phase processing methods. This research investigated the feasibility of producing surface composites of aluminium-based dissimilar alloys reinforced with functional microparticles through experimental validation, determined the process parameters that resulted in a more homogeneous distribution of the particles in the surface composites, and enhanced the understanding of Upward Friction Stir Processing (UFSP) technology. The production of aluminium-based dissimilar alloys (AA 7075-T651 and AA 6082-T651) surface composites reinforced with SiC particles was studied, and it was concluded that the macrography and micrography analyses, scanning electron microscopy (SEM) analysis, microhardness measurements, and eddy currents technique reveal an extensive and homogeneous incorporation of SiC particles. In the stirred zone, a decrease of approximately 20 HV 0.5 in hardness was observed compared to the base material. This reduction is attributed to the weakening effect caused by low-temperature annealing during UFSP, which reduces the strengthening effect of the T651 heat treatment. Additionally, the presence of particles did not affect the surface composite hardness in the stirred zone. Furthermore, despite the presence of significant internal defects, SEM analyses revealed evidence of the lower alloy merging with the upper zone, indicating that the lower plate had a role beyond being merely sacrificial. Therefore, the production of bimetallic composites through UFSP may offer advantages over composites produced from a monometallic matrix. The results of the eddy currents testing and microhardness measurements support this finding and are consistent with the SEM/EDS analyses.

Surface metal-matrix composites based on AZ91 magnesium alloy via friction stir processing: A review

Surface metal-matrix composites based on AZ91 magnesium alloy via friction stir processing: A review

Investigation into microstructural evolution, mechanical and tribological properties of an aluminum surface composite developed using a severe plastic deformation technique

Aluminum based surface metal matrix composite was developed with 15% and 20% of TiCp reinforcement using multi-pass friction stirring process. The effect of TiC reinforcement and multiple FSP passes on microstructural evolution was characterized using optical, X-ray diffraction, electron microscopy, and electron backscattered diffraction techniques, while texture formation was analyzed using the neutron diffraction method. Hardness and tribological investigations were carried out to examine the mechanical behavior of the reinforced surface. A defect-free, uniformly reinforced composite surface with increased matrix-reinforcement interface was attained with 15% TiC after six passes. Hardness improved substantially to 215 HV due to the combined effect of zener pinning, grain refinement, uniformly dispersed reinforcement and increased dislocation density in the matrix. Better texture index was observed on the composite surface with Copper and S as dominating texture components. Significant wear resistance was exhibited by the composite at lower load due to strong adherence of TiC to the matrix, which however decreased with increase in loading conditions. Wear surface examination revealed that the mode of wear was predominantly abrasive.

Surface Modification and Parametric Optimization of Tensile Strength of Al6082/SiC/Waste Material Surface Composite Produced by Friction Stir Processing

Friction stir processing (FSP) is one of the promising tools to enhance the mechanical and microstructural features of any engineering material due to its excellence in grain refinement. Further, the successful utilization of waste material into a useful product instigates the use of chicken bone powder (CBP), walnut shell powder (WSP), and rice husk powder (RHP) as secondary reinforcement to develop surface composites and metal matrix composites to enhance the mechanical properties. In the present work, a surface composite of base alloy Al6082 is developed through the utilization of SiC as primary reinforcement and CBP, WSP, and RHP as secondary reinforcement. The experiments were performed as per Taguchi’s L9 orthogonal array and the analysis of variance (ANOVA) response is discussed in detail. The process parameters taken for the study are the type of tool pin profile such as hexagonal, square, and cylindrical threaded along with rotational speed and tool tilt angle. The result revealed the microstructural characterization through field emission scanning electron microscopy (FESEM) images equipped with energy-dispersive X-ray spectroscopy (EDS) phase mapping and elemental spectrum. The tensile strength of each specimen was tested through a horizontal tensometer and further studied to get the optimized value of the process parameter to achieve a larger value. The use of a hexagonal pin profile with the optimized value of the rotational speed of 1500 rpm and 3° tilt angle gives the higher tensile strength of 250.64 MPa.

Investigating the effects of different particulate deposition techniques on the fabrication of AA 2014/TiC surface composites using friction stir processing

Aluminium matrix surface composites play a significant role as in many of the engineering application surface properties rather than bulk properties determines the life of the components. Friction stir processing (FSP) which is a thermo-mechanical process is emerging as an excellent choice for fabricating metal matrix surface composites. The present work aims to study the effects of different particulate deposition techniques for the processing of AA2014/TiC surface composite using FSP. Three different reinforcement techniques were considered in this research work and microhardness of each processed specimen was measured. The observed microhardness value for all three specimens was greater than the microhardness value of the base material (BM). But the reinforcement technique with groove capped by the means of a pin less FSP tool shows a substantial enhancement in microhardness value of 25.37%. Performing FSP without capping the groove results in the agglomeration of the reinforcing particles. This also resulted in increased tool wear because of the direct interaction of reinforcing particles with the FSP tool. A defect-like cavity was formed during FSP when the reinforcing particles were filled in the blind holes. The experimental results demonstrated that for fabricating surface composites using FSP, a straight capped groove shows a significant enhancement in microhardness compared to the other two techniques.

Effect of process parameters on surface composite fabrication of newly commercialized Mg-ZE41 alloy by friction stir processing (FSP): microstructural development and microhardness

PurposeAltering the microstructure and developing the surface metal matrix composites (MMCs) in a solid-state by friction stir processing (FSP) has been on trend for the past decade. The microstructural modification increases the material properties, which are structure sensitive. The microstructural evolution is highly influenced by the selection of process parameters in FSP. In this study, the effect of process parameters on the microstructure evolution and microhardness of the fabrication of surface MMCs of newly commercialized Mg-ZE41 alloy by the incorporation of different reinforcement particles such as ZrO2, CeO2 and Al2O3 is investigated.Design/methodology/approachBy making use of Taguchi’s design of experimentation, which recognizes the crucial factors and ascertain their effect on the properties of the material, the optimization of process parameters for this study was done using MATLAB-14 software. The parameters were adopted along with the levels throughout the FSP for the fabrication of different surface MMCs. For each reinforcement particle, two factors at three levels each had L9 factorial design were used to analyse the effect of these factors on the processing result (microstructure, grain refinement and hardness). The two different factors used in this study are tool rotational speed (TRS) and tool traverse speed (TTS) as a part of the full factorial design matrix for different surface MMCs.FindingsAmong all combinations, TRS of 1500 rpm and TTS of 20 mm/min. for ZE41-ZrO2 MMCs and ZE41-CeO2 MMCs were observed as optimum to produce defect-free processed zone along with the high level of grain refinement and hardness, whereas for ZE41-Al2O3 the same was obtained at 1500 rpm TRS and 10 mm/min TTS.Originality/valueIn this paper, the role of process parameters in the development of surface MMCs on newly commercialized Mg-ZE41 alloy by FSP is investigated. The effect of TRS and TTS on microstructure evolution, grain refinement and microhardness is analysed. Hence, in this study, the optimum parameters for the fabrication of surface MMCs of Mg-ZE41 alloy have thus been established.

Sputter-grown hierarchical nitride (TiN & h-BN) coatings on BN nanoplates reinforced Al7079 alloy with improved corrosion resistance

A boron nitride nanoplates (BNNPs) reinforced aluminium alloy (Al7079) based ex-situ metal matrix (MM) nano-composite was successfully developed via mechanical stir casting process. This MM nano-composite shows better wetting and anti-corrosion properties in comparision of bare Al7079 alloy. To further enhance the aforementioned properties, two dissimilar hard coatings (TiN & h-BN) with hierarchal rough surfaces were employed on the BNNPs functionalized MM composite surface via a single-step PVD technique, which provide a tough barrier with non-wetting surface to prevent the base material from corrosion attack. The addition of these layers led to a significant change in physical, chemical, mechanical and anti-corrosion properties. The results also revealed the hydrophobicity of developed coatings with optical contact angle meter of TiNNCs and h-BNNPs surfaces ~102.1° and 141.6°, respectively. The collective results obtained from electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization tests revealed the one order higher corrosion resistance of h-BN coated sample than TiN coated sample under saline media (3.5 wt%). This coating may be a promising candidate in various applications, where the protection of materials against corrosion is necessary. • Development of BN nanoplates reinforced aluminum alloy (Al-7079) metal matrix by mechanical stir casting. • The MM nano-composite shows better wetting and anti-corrosion properties as compare to base Al7079 alloy. • TiNNCs and h-BNNPs were employed on the BNNPs-Al7079 composite surface via a single-step PVD technique. • Better hydrophobicity and high corrosion resistance shown by BNNPs coated sample compared to TiNNCs coated sample.

Fabrication of surface metal matrix composites for structural applications using friction stir processing – A review

Surface metal matrix composites (SMMCs) are the best choice materials for recent advanced engineering applications. In this regard, friction stir processing (FSP) is gaining popularity as a promising method for producing SMMCs. FSP is extensively used to make magnesium and aluminum based SMMCs. In addition, this technique is also suitable to produce surface composites made from steel, copper, and titanium-based alloys. The FSP of metals can improve the mechanical properties e.g., ductility, strength, fatigue life, abrasion resistance, corrosion resistance, hardness, and formability. This paper provides a comprehensive overview of FSP of single and hybrid fillers reinforced SMMCs along with the influence of process parameters to enhance the mechanical properties and tribological behavior of SMMCs. Tool variables and processing parameters frequently influence the properties of FSPed SMMCs. Due to the significant impact of tool variables at high melting temperature zone, especially for the hard SMMCs, a quick word on tool design parameters and their limitations are systematically presented. The numerous research articles are reviewed in detail to determine the effects of tool and process parameters, multiple passes of the tool in the process zone, and reinforcing particles on grain refinement during fabrication of SMMCs. To determine the effective machine/process parameters, it is necessary to examine the underlying mechanisms involved during FSP thoroughly. With the help of reported models, the fundamental mechanisms in the strengthening of FSP manufactured SMMCs are examined in this paper. Enhancements of mechanical properties and wear behavior on aluminum SMMCs due to mono and hybrid reinforcements are also reviewed. Common defects during processing and their remedial are deliberated. FSP technique has several research needs, such as producing customizing microstructures with defect-free composites are also discussed in this study.

Effect of Zirconium Dibromide and Aluminum Oxide Hybrid Particle Reinforcement on the Mechanical, Microstructure and Wear Properties of AA6063 Surface Metal Matrix Composite

In the present study Aluminum 6063 as the matrix and with Zirconium dibromide and Aluminum oxide as the reinforcement particle Metal Matrix surface composites were fabricated by friction stir processing. By the addition of reinforcements such as Zirconium Dibromide and Aluminum Oxide used as the strengthening agents during FSP process certainly made the MMC more wear resistant and harder than the base matrix. The effect of varying reinforcement percentage on the Mechanical wear and microstructure properties were studied. The Micro hardness showed an increasing trend in the nugget zone. The wear rate decrease with increase in volume percentage of hybrid reinforcement. FESEM images of the samples displayed uniform distribution of the particle in the matrix. And also reiterated the formation of hybrid particles.

Characterisation of Aluminium Ni–40Fe–10Ti fabricated by friction stir processing

ABSTRACT Aluminium metal matrix surface composites are gaining more attention in industries such as aerospace, marine and defence, due to the improved hardness, strength, ductility and better resistance to corrosion. In this study, Al/Ni–40Fe–10Ti surface composites were fabricated using friction stir processing (FSP) and the effect of tool rotational speed and transverse speed on the microstructural and mechanical properties was studied. Processing parameters chosen for the experiment are tool rotational speeds between 600 rpm and 1000 rpm, and transverse speeds between 70 mm/min and 210 mm/min. The results show that at a tool rotational speed of 1000 rpm and at transverse speeds of 140–210 mm/min, the hardness values were found to be improved significantly from 38 Hv of the base metal to 41 Hv of the friction stir processed (FSPed) surface. The tensile strength was also found to be improved in a sample produced at a rotational speed of 1000 rpm and transverse speed of 70 mm/min. Tool rotational speed and transverse speed have a greater influence on the mechanical properties of friction stirred process surface because of the high heat input generated in the weld region causing proper mixing and incorporation of the reinforcing Ni–40Fe–10Ti powder.

Experimental investigations on effect of surface treatment of aluminum based metal matrix composites using laser

Laser sintering is one of the most widely used methods for fabricating advanced materials such as metal matrix composites (MMC). It offers a great deal of flexibilities to deal with complex shapes. Laser sintering is also a critical method to deal with constituents of metal matrix composites with higher melting point and hardness. In the present work, an attempt is made to present an experimental study wherein Al-MMC is fabricated first with the powder metallurgy route. Then surfaces of MMC are treated with laser. The effect of laser treatment on hardness and wear property is investigated. The treatment of laser on the surface of MMC resulted in increased hardness as compared to untreated MMC, and the wear resistance is found better along with the increased percentage of reinforcement particles. The work also presents a study on the application of laser to process Metal Metric Composite. It gives an idea of different associated process parameters like laser power, scanning speed, and their effect on MMC.

Special Issue on Tribology of Additive Manufacturing

Special Issue on Tribology of Additive Manufacturing

Recent Developments in Hybrid Surface Metal Matrix Composites Produced by Friction Stir Processing: A Review

AbstractThe metal matrix composites combine the metallic properties of a tough and ductile matrix with properties of reinforcement particles, simultaneously develop the functional properties by proper selection of reinforcements for projected applications. However, hard ceramics reinforcements decrease toughness and ductility of soft matrix and restrict their wide applications. The surface metal matrix composites (SMMCs) preserve the matrix properties with added advanced surface properties by reinforcing particles only in the surface layer. The hybrid surface metal matrix composites (HSMMCs) with more than one reinforcement gained attention in material processing due to their noble tribological behavior and surface properties, which cannot be attained in mono composites. Conventional liquid-phase processing techniques to fabricate hybrid surface composites result in the formation of undesirable brittle compounds, detrimental to desirable properties of composites. Friction stir processing (FSP), a solid-state processing technique, has been used by many investigators using different reinforcements to fabricate mono as well as hybrid surface composites. Friction stir processed (FSPed) hybrid surface composites have not been extensively reviewed. The current review provides a comprehensive understanding of the latest developments of FSP in hybrid surface composites manufacturing. This paper review different reinforcement strategies in the fabrication of FSPed hybrid surface composites and also the effects of single-pass, multipass, and change in pass direction on microstructure and resultant properties. Finally, future directions and challenges to FSPed hybrid surface composites are summarized. This review article containing important information on hybrid surface composites fabrication by FSP will be useful to academicians and investigators in the field.

Studies on Al-MWCNT MMC surface coating on Aluminium substrates through friction surfacing process

In this study, Aluminium-Multi Wall Carbon Nano Tube (Al-MWCNT) metal matrix composite surface coating was fabricated by using solid state friction surfacing technique on Al substrate. The influence of process parameters on the coating dimensions, integrity and hardness was examined. The optical microscopy studies revealed that the coating integrity with the substrate is good with Trial-2 parameters i.e RPM 2500, Axial Load 700Kg and Traverse Speed 6mm/s. Grain refining due to the dynamic recrystallization was observed in the coating microstructure. XRD studies revealed that the MW-CNTs were distributed in to the coating and no detrimental intermetallic compounds were formed between Al matrix and MW-CNTs except Al4C3. The Scanning Electron Microscopic Studies reveals that the Al metal was severely deformed before forming the coating which is evident from the flow lines. It is further confirmed from the SEM studies that the MW-CNTs were dispersed uniformly within the coating and the nano size was retained in the coating without significant coarsening.

Tribological behavior of friction stir processed AA6061 aluminium alloy

Abstract In the age of light weight, aluminum alloys are used as one of the most predominant materials in automotive and aircraft industries. But their applications are being restricted where tribological (relative motion between parts) is major issue. Thus, coating metallic substrates i.e. aluminum alloys with ceramic powders is an effective solution in prolonging the component service life. The present investigation aims at changing the surface morphology by introducing carbide powders (180 µm) of boron, silicon and tungsten on to AA 6061 Al alloy (widely used in automobile components) using friction stir processing. Fabricated surface metal matrix composites (SMMCs) exhibited better wear resistance compared to the base metal. SMMC (127VHN) consisting B4C as reinforcement has shown superior wear resistance among other SMMCs made from WC and SiC respectively. From the SEM analysis, it is clearly observed that abrasion wear is the primary cause for less wear resistance in AA 6061 aluminium alloy while as adhesive wear mechanism is found to be predominant one in all other surface composites resulting in the increase of wear resistance. Thus, it is recommended to use B4C as reinforcing material for surface modification of AA6061 aluminum alloy when compared with other reinforcing materials of WC and SiC.