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In this study, the environmentally friendly friction stir processing (FSP) method was utilized to fabricate surface composites employing technical aluminum matrix 1050-H14 and aluminum alloy 6060-T4 reinforced with silicon carbide (SiC) particles. Microstructure analysis, employing light and scanning electron microscopy, in conjunction with comprehensive evaluations of hardness, compressive strength, and tribological properties, was conducted to elucidate significant findings. The results reveal that an augmented number of FSP passes contributes to the homogenization of microstructure, leading to the alteration of SiC particle morphology and fragmentation. Consequently, this phenomenon results in improved mechanical properties, particularly noteworthy in the case of AA6060-T4 alloy matrix composites, and enhanced wear resistance. Both AA1050-SiC and AA6060-SiC composites demonstrate notable increases in compressive strength compared to their unreinforced matrices. Particularly noteworthy is the substantial enhancement in compressive strength observed in the AA6060-SiCp composite, escalating from 249 to 331 MPa (at ε = 0.1) and from 398 to 715 MPa (at ε = 0.2) with an increase in the number of FSP passes. Additionally, FSP's ability to precisely control process parameters such as tool rotational speed and traverse speed allows for the optimization of mechanical properties and microstructural characteristics tailored to specific application requirements. This study highlights the potential of FSP in fabricating high-performance aluminum matrix composites with superior strength and wear resistance, positioning it as a viable technique for advanced engineering applications. The environmentally friendly nature of FSP, due to its solid-state operation and reduced energy consumption, further underscores its suitability for sustainable manufacturing practices. [ABSTRACT FROM AUTHOR]

This study investigates the corrosion resistance and wear behaviour of aluminium matrix composites (AMCs) manufactured through the ultrasonic-assisted stir-casting technique. These composites were synthesized by introducing titanium carbide (TiC) and nickel (Ni) into aluminium alloys (AA6061). The X-ray diffraction results confirmed the presence of α-Al, TiC and Al3Ni phases within the composites. Microstructural examination demonstrated an uniform dispersion of TiC particles and dispersion of Al3Ni along grain boundaries. To evaluate the corrosion behaviour, samples were subjected to immersion tests and electrochemical techniques, including potentiodynamic polarization and electrochemical impedance spectroscopy (EIS), in a 3.5 wt% NaCl solution. Immersion tests indicated that the composites exhibited slower dissolution rates than base AA6061 alloys. Potentiodynamic polarization results revealed that the inclusion of TiC and Ni reinforcements enhanced corrosion resistance, with TiC having a more pronounced influence. The EIS tests suggested that the composites had higher charge-transfer resistance than AA6061 alloys. After conducting corrosion tests, scanning electron microscope (SEM) images of the base AA6061 alloys unveiled the presence of deep pits but the inclusion of reinforcements resulted in the shallow pits. In addition, Vickers hardness tests and pin-on-disc wear tests were conducted to investigate hardness and wear properties. Notably, hybrid composites containing 3% TiC and 3% Ni exhibited a substantial 42.18% increase in hardness as compared to the base alloy. These hybrid composites also demonstrated superior wear resistance, with a wear rate that was 58.6% lower compared to AA6061 alloy and 41% less than that of the 3% Ni-reinforced composite. [ABSTRACT FROM AUTHOR]

The paper presents the results of testing the wear resistance and coefficient of friction (COF) tools made of SikaBeresin® F50 polyurethane resin intended for dies and punches for the cold sheet metal forming process. Seven sets of composite tools (rotating rings) additionally reinforced with waste metallic powders from Al and Cu alloys (5-20% by volume) from the dry cutting process of pipes and rods were tested. Wear resistance tests and determination coefficient of friction were carried out using the T-05 block-on-ring tribotester. The tests were performed for heat and corrosion resistant sheets made of nickel alloy AMS5599 (Inconel 625), iron alloy AMS5510 (321) and aluminum alloy sheets AMS4026 (6061-T4). Composite tools with the addition of 20% aluminum powder (A+B+C+20%Al) tested with a specimen of steel alloy AMS5510 and nickel alloy AMS5599 were characterized by the lowest wear resistance. In each case, the composite rotating ring without reinforcements was characterized by the lowest coefficient of friction. The use of Cu powder reinforcements in each case had a positive effect on increasing wear resistance. The best wear resistance of 0.011% was obtained for composite rotating ring with the addition of 10% copper powder paired with specimen of nickel alloy AMS5599 sheet. [ABSTRACT FROM AUTHOR]

Abrupt advancement in technologies lead to growing thirst for efficient and economical alternative materials that possess superior properties. This lead to a gradual shift from the use of monolithic alloys to Metal Matrix Composites (MMCs). High resistance to corrosion and wear makes Aluminium MMC (AMMC) the most promising variant for structural, automotive, marine and aerospace applications. This review opens an insight into the current advancement of AMMCs, detailing an overview on diverse matrices and types of reinforcements that were used to produce such composites. This work also explores and classifies the gain and shortcomings of various phase formations during thermal treatment, revealing the possibilities of improving the physical strength and wear resistance with minimal complexity. This work also highlights the growing concern on corrosion performance of advance AMMC with ceramic reinforcements. In spite of the challenges involved in commercialising AMMC, recent trends of industrial utility reveal their potential to meet evolving demands. [ABSTRACT FROM AUTHOR]

Aluminium-carbon nanotube (Al-CNT) composites have proven to offer a lot of potential for applications involving friction and wear. This study investigated the wear behaviour of Al-CNT composites with uniformly dispersed CNTs without structural damage at concentrations of 0.5 wt%. The wear behaviour of these composites has been compared with that of pure aluminium, which was fabricated using the identical wet shake mixing, compaction, and extrusion procedure. The study aimed to determine how CNT concentration and applied stress influence the wear behaviour of composite materials. Scanning electron microscope (SEM) was used by the researchers to examine the surface features of the worn samples. The study showed a significant increase in hardness and wear resistance with adding CNT. Compared to pure aluminium, the composite containing 0.5 wt. % CNTs demonstrated a 25% reduction in wear rate, and the average value of the coefficient of friction (µ) also decreased. The wear rate and coefficient of friction increased when samples containing 0.5 wt. % CNTs were subjected to various loading scenarios. The major contribution of CNTs to improving wear characteristics was discovered through SEM investigation of these worn surfaces. Using the ANSYS Workbench, a built finite element model was used to perform contact analysis on the disc and pin. Analytical results and experimental data were contrasted, and the ANSYS data was utilised to assess the process parameters. The comparison confirmed the analysis accuracy and dependability, which showed a consistent agreement between the analytical findings and the experimental results. [ABSTRACT FROM AUTHOR]

In today's manufacturing industries, Metal Matrix Composites (MMCs) are in high demand owing to their valuable properties like high strength-to-weight ratio and resistance against wear. This research evaluates the wear properties of AA2219 matrix composites reinforced using varying amounts (2%, 4% and 6% by weight) of Si3N4 particles, fabricated by squeeze casting. Wear performance testing of the developed Aluminium Matrix Composite (AMC) is executed by utilising pin-on-disc equipment subjected to varying conditions of load and speed. The wear rate is reported to rise with increasing normal load and sliding velocity. The study also reveals that the wear rate reduces with increasing reinforcement content. [ABSTRACT FROM AUTHOR]

The extraordinary mechanical properties of AA7075-T6 alloy are comparable to that of steel, but its low hardness, high wear rate at room and high temperature have limited its widespread use, so the main aim of this study is to eliminate these weaknesses by producing a hybrid surface composite with the help of an intermetallic compound (Al3Zr) and other reinforcements (Al2O3 and ZrO2). Friction stir processing was chosen for this purpose, so in addition to obtaining extremely refined grains, the formation of common defects, occurring in the conventional methods, could be avoided. Having produced the composite, surface appearance was evaluated and microstructural characteristics were investigated by stereo, light, and FESEM microscopes. Besides not observing any external and internal critical defect, ultra-fine grains were seen. For a detailed investigation, EDS and XRD analyses were used. To assess mechanical properties, tensile and microhardness tests were conducted. Although yield and UTS experienced a fall, the particles set the stage for remarkable improvements in microhardness, cold, and hot wear. Microhardness was raised uniformly in the whole stir zone, and a ~ 48% rise in this property was obtained. Moreover, hot and cold wear resistances were improved up to about 85% and 65%, respectively. Finally, to study the mechanisms of the fracture and wear, the surfaces were scrutinized under SEM and EDS. It was observed that the fracture had a combination of ductile and brittle behaviors and in worn surfaces, instead of cavities formation, micro-cracks and scratches were produced, which are the signs of enhancement in wear resistance. [ABSTRACT FROM AUTHOR]

In this paper, we designed the A356-B2O3-KBF4 reaction system to synthesize (AlB2 + Al2O3)/A356 biphasic particles-reinforced aluminum matrix composite with varying weight percentages (2%, 4%, 6%, and 8%). The synthesis was achieved through mechanical mixing and mixed salt reaction. We studied the friction and wear performance of the composite at room temperature using XRD, PC, SEM, EDS, laser confocal microscopy, and microhardness analysis. Our results indicate that the AlB2 and Al2O3 duplex-enhanced particles were effectively synthesized, with predominantly short rod morphology and local clustering observed for the AlB2 particles. The AlB2 particles were mostly in the micron-scale range, while the Al2O3 particles were mostly in the nanoscale range, both exhibiting agglomeration phenomena. Both enhanced particles showed an agglomeration phenomenon and could grow together with the interface binding very closely. At 6 wt.% mass fraction of biphasic particles, the composite exhibited the best refinement effect on-Al grains, as well as the greatest friction reduction effect and wear resistance for both the (AlB2 + Al2O3)/A356 composite and the A356 matrix alloy. The wear mechanism was primarily abrasive wear, while the A356 matrix alloy's wear mechanism was adhesive wear. [ABSTRACT FROM AUTHOR]

This study investigates the tribological properties of an AA 5754 aluminum alloy composite reinforced with the nanopowder of Al2O3, fabricated using the friction stir processing (FSP) technique with blind holes. The aim is to analyze the effects of varying the tool rotational speed (rpm) and blind hole diameter on the wear and friction behavior of the produced composite. A pin-on disk test is conducted under dry conditions and room temperature to assess the tribological properties against steel. Scanning electron microscopy (SEM) coupled with energy dispersive X-ray spectroscopy (EDS) is employed to examine the worn and wear surfaces of the produced composites post test. The results indicate that increasing the applied load results in a decrease in the coefficient of friction (COF), with values ranging from 0.775 to 0.852 for 10 N and 0.607 to 0.652 for 20 N. Moreover, the wear rate diminishes with higher Al2O3 content and optimal FSP tool rotation (1280 rpm). Hardness analysis reveals variations between 33–42 HV and 35–39 HV, influenced by nanoparticle distribution. The composite demonstrates superior wear resistance compared to raw AA5754 aluminum due to its reinforced nature. However, high FSP tool rotation rates lead to abrasive wear and surface cracks. These findings offer insights into optimizing FSP parameters to enhance the tribological performance of nano-reinforced aluminum alloys. [ABSTRACT FROM AUTHOR]

The current study attempted to introduce nano-aluminium oxide (Al2O3) particles into ZE41 alloy via friction stir processing (FSP). The effect of these nano-Al2O3 particles on the mechanical and tribological characteristics of ZE41 alloy is investigated. The results of microstructural studies revealed the uniform distribution of Al2O3 particles and substantial grain refinement in the stir zone by FSP. Enhanced microhardness was observed in the processed region due to the grain refinement and the occurrence of regularly distributed Al2O3 particles. The wear resistance was also seen increased with the incorporation of the Al2O3 particles. Moreover, the effect of FSP parameters on the successful incorporation of nano-Al2O3 particles in ZE41 alloy without any defect is also realised. [ABSTRACT FROM AUTHOR]

In this study, liquid casting process is used to fabricate AA1050/SiC composites. To increase the wettability of molten Al and improve the adhesion of particles to metallic matrix, liquid casting was selected as the fabrication process. AA1050 and Nano-SiC particles were selected as metallic matrix and reinforcements, respectively. Then, wear, mechanical properties, fracture toughness and forming limit diagram of (FLD) of aluminum composite samples have been investigated experimentally. To do this, AA1050/SiC composite strips with thickness of 1 mm have been fabricated up to eight ARB passes at 300∘C. The graining was investigated via optical microscopy (OM). The ultimate tensile strength (UTS) of samples improved to 170 MPa registering 168% improvement than the initial monolithic sample. Also, the bonding quality among the layers improved by decreasing the thickness of layers at higher number of passes (increasing the plastic strain). SEM fracture surface morphology of samples after the tensile test showed that by increasing the ARB passes, shear ductile was the fracture mode. So, deep dimples are shrinking slowly relative to the annealed sample. The FLDs' area dropped sharply for pass 1 and then improved at higher passes as the criterion of formability. Also, wear resistance of composite samples was better than monolithic sample. Moreover, at the 10th pass, the fracture toughness enhanced to the maximum value of 33.5 MPam 1 / 2 . [ABSTRACT FROM AUTHOR]

Purpose: The purpose of this study is to reveal the effect of nano-Al2O3 particle addition on the nucleation/growth kinetics, microhardness, wear resistance and corrosion resistance of Co–P–xAl2O3 nanocomposite plating. Design/methodology/approach: The kinetics and properties of Co–P–xAl2O3 nanocomposite plating prepared by electroplating were investigated by electrochemical measurements, scanning electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, Vickers microhardness measurement, SRV5 friction and wear tester and atomic force microscopy. Findings: A 12 g/L nano-Al2O3 addition in the plating solution can transform the nucleation/growth kinetics of the plating from the 3D progressive model to the 3D instantaneous model. The microhardness of the plating increased with the increase of nano-Al2O3 content in plating. The wear resistance of the plating did not adhere strictly to Archard's law. An even and denser corrosion product film was generated due to the finer grains, with a high corrosion resistance. Originality/value: The effect of different nano-Al2O3 addition on the nucleation/growth kinetics and properties of Co–P–xAl2O3 nanocomposite plating was investigated, and an anticorrosion mechanism of Co–P–xAl2O3 nanocomposite plating was proposed. [ABSTRACT FROM AUTHOR]

Aluminum matrix composites (AMCs) have garnered significant attention across various industrial sectors owing to their remarkable properties compared to conventional engineering materials. These include low density, high strength-to-weight ratio, excellent corrosion resistance, enhanced wear resistance, and favorable high-temperature properties. These materials find extensive applications in the military, automotive, and aerospace industries. AMCs are manufactured using diverse processing techniques, tailored to their specific classifications. Over three decades of intensive research have yielded numerous scientific revelations regarding the internal and extrinsic influences of ceramic reinforcement on the mechanical, thermomechanical, tribological, and physical characteristics of AMCs. In recent times, AMCs have witnessed a surge in usage across high-tech structural and functional domains, encompassing sports and recreation, automotive, aerospace, defense, and thermal management applications. Notably, studies on particle-reinforced cast AMCs originated in India during the 1970s, attained industrial maturity in developed nations, and are now progressively penetrating the mainstream materials arena. This study provides a comprehensive understanding of AMC material systems, encompassing processing, microstructure, characteristics, and applications, with the latest advancements in the field. [ABSTRACT FROM AUTHOR]

Developing photothermal anti/deicing fluor‐free composite coatings with high wear resistance and liquid puncture resistance is an interesting challenge. Herein, a new biomass benzoxazine monomer (C‐d) was synthesized, which was then sprayed on a glass slide, followed by spraying hyperbranched polysiloxane (HSi), polydopamine‐coated micro AlN (P@mAlN), and polydopamine‐coated nano AlN (P@nAlN), successively, to develop a new type of photothermal anti/deicing four‐layer fluor‐free composite coatings with high wear resistance and liquid puncture resistance (C‐d/yHSi/0.4P@2bAlN, y is the mass ratio of HSi to C‐d). Three‐layer composite coatings (C‐d/0.4P@zbAlN, z is the mass ratio of P@mAlN to P@nAlN) and two‐layer composite coatings (C‐d/xP@mAlN, x is the mass ratio of P@mAlN to C‐d) were also prepared to study the influence of compositions on comprehensive properties of coatings. The results show that C‐d/0.4P@zbAlN has significantly longer icing delay time (IDT) than C‐d and C‐d/xP@mAlN coatings but still shows poor wear resistance and liquid puncture resistance. Interestingly, C‐d/yHSi/0.4P@2bAlN coatings have good superhydrophobicity; as y increases, both IDT and wear resistance increase significantly. When y = 0.5, the obtained C‐d/0.5HSi/0.4P@2bAlN coating has the best integrated performance, including high anti‐deicing property (IDT = 627 s), high wear resistance, and liquid puncture resistance as well as good photothermal deicing performance, the ice melts in 343 s under the irradiation with 808 nm infrared light, overcoming the bottleneck of poor wear resistance and liquid puncture resistance of photothermal anti/deicing coatings. Besides, C‐d/0.5HSi/0.4P@2bAlN coating can effectively prevent the adhesion of pollutants and remain superhydrophobicity after soaked in different solutions (pH = 1–10). Highlights: A new biomass benzoxazine with good flexibility was synthesized.Photo‐thermal anti/deicing coatings with micro/nanostructured surfaces are built.The fluor‐free coatings have excellent wear resistance and chemical resistance.The mechanism behind was elucidated. [ABSTRACT FROM AUTHOR]

This research deals with the mechanical and tribological behaviour of different weight percentages of reinforcements (coated silicon carbide, boron carbide, and graphene oxide) dispersed with aluminium matrix (Al 6061) composites. The silicon carbide (SiC) was coated by Titanium oxide (TiO2) using the Electro Phoretic Deposition (EPD) method. The selected mix proportions fabrication process was performed by the stir casting method. The tribological and mechanical behaviour of hybrid aluminium matrix-composite specimens and Scanning Electron Microscopy (SEM) identification revealed that ASB-1 (86 wt% Al 6061 + 2 wt% GO + 10 wt% SiC + 2 wt% B4C) uncovered higher wear resistance and strengths due to reinforcement's uniform distribution throughout the aluminium matrix and coating of SiC. Moreover, a comparison was performed to determine the effectiveness of hybrid composite specimens. It is concluded that the presented SRNMS framework identified the mix proportions effectively, and the coating of SiC improves the wear resistance. [ABSTRACT FROM AUTHOR]

Aluminum matrix reinforced with carbide powders is considered one of the best ways to improve abrasion resistance in pure alloys. Thus, this study aims to evaluate the abrasive wear resistance of A380 aluminum alloy reinforced with different amounts of NbC reinforcement. The A380 aluminum alloy was selected as the matrix and melted at a temperature of 750°C in an induction furnace. Three weight fractions of NbC powder (5 wt%, 10 wt%, and 15 wt%) and one without NbC were chosen as the reinforcement material and were added using the stir casting method at 400 rpm for 5 min. Mg acts as a bonding agent, Sr was used to modify the eutectic phase, and Al5Ti1B was a grain refiner. Three-body abrasive wear test was conducted in accordance with the ASTMG65 standard. The material properties were evaluated by hardness test, grain size determination, density, porosity, and metallographic analysis. The composite shows an increase in wear resistance and hardness as the NbC content was elevated, especially in the sample containing 15 % NbC. The worn surfaces showed a similar pattern with grooves and plowing, and the highest fraction of NbC (15%) had the lowest amount of plowing. [ABSTRACT FROM AUTHOR]

Aluminum matrix composites (AMCs) find extensive use across diverse industries such as automotive, aerospace, marine, and electronics, owing to their remarkable strength-to-weight ratio, corrosion resistance, and mechanical properties. However, their limited wear resistance poses a challenge for applications requiring high tribological performance. Abrasive wear emerges as the predominant form of wear encountered by AMCs in various industrial settings, prompting significant research efforts aimed at enhancing their wear resistance. Over the past decades, extensive research has investigated the influence of various reinforcements on the abrasive wear behavior of AMCs. This paper presents a comprehensive review of the impact of different variables on the wear and tribological response of aluminum composites. This review explores possible wear mechanisms across various tribosystems, providing examples drawn from the analysis of existing literature. Through detailed discussions on the effects of each variable, conclusions are drawn to offer insights into optimizing the wear performance of AMCs. [ABSTRACT FROM AUTHOR]

This study investigates the fabrication, wear characterization, and coefficient of friction (COF) prediction of open-cell AlSn6Cu–Al2O3 composites obtained by a liquid-state processing technique. Focusing on wear behavior under varying loads using the pin-on-disk method, this research characterizes microstructure and phase composition via SEM, EDS, and XRD analyses. A novel aspect of this research is the application of an LSTM recurrent neural network model for the fast and accurate prediction of the COF of the composites, eliminating the need for extensive experimental work. Additionally, feature importance analysis using Random Forest regressors is conducted to ascertain the relative contribution of each input variable to the output variable, enhancing our understanding of the wear mechanisms in these materials. The results demonstrate the effectiveness of the composite's reinforcement in improving wear resistance, highlighting the critical role of mechanical stress and the reinforcement's hardness in the wear process. The quantitative findings related to the wear behavior include a mass-wear reduction in the open-cell AlSn6Cu–Al2O3 composite from 8.05 mg to 1.90 mg at 50 N and a decrease from 17.55 mg to 8.10 mg at 100 N, demonstrating the Al2O3 particles' effectiveness in improving wear resistance under different loads. [ABSTRACT FROM AUTHOR]

In this paper, a brake cylinder coating comprising a composite material of an Fe3Al and Cr3C2 mixed powder was prepared by adding laser cladding onto carbon structural steel. We studied the influence of process parameters on the microstructure and tribological properties of the cladding materials using scanning electron microscopy (SEM), energy-dispersive spectroscopy (EDS), and 3D white light interferometer and wear tests. The influence of different processes on the morphology of the carbide strengthening phase was found to be relatively small with a Cr3C2 content of 15 wt.%. The carbides mainly exhibited a network structure in each group of cladding layers. The area of the network strengthening phase varied under different processes. Of the cladding layers formed with different processes, the scanning speed of the 0.003 m/s cladding layer had the lowest wear rate. When the laser power was too low or the powder feed rate was too high, unmelted Cr3C2 particles could be found in the cladding layer. During the wear process, the particles peeled off, causing severe abrasive wear. When the powder feeding rate was too low, more materials in the base material entered the cladding layer. This made the composition of the cladding layer similar to that of the grinding material, resulting in severe adhesive wear. [ABSTRACT FROM AUTHOR]

In this study, high-hardness Silicon Nitride (Si3N4) particles were spatially dispersed with aluminium A356 alloy, making A356 reinforced with 10 wt.% Si3N4 Functionally Graded Metal Matrix Composite (A356-10 wt.% Si3N4 FGMMC) through vertical centrifugal casting route. The gradient particle distribution and phase analysis were verified along the radial direction. The hardness and sliding wear behaviour were evaluated using Vicker's microhardness tester and pin-on-disc tribometer. The superior microhardness (182 HV) was observed at the exterior surface, which was 73% higher than the interior surface. In the dissimilar zones of the FGMMC, wear performance was assessed with the applied loads of 20, 40, and 60 N at sliding velocities of 2, 3 and 4 m/s during the sliding distances of 500, 1250, and 2000 m. Taguchi's technique and Analysis of Variance (ANOVA) were implemented to pinpoint the optimum and momentous sliding wear variables. The lowest wear rate of 0.749 × 10−4 is identified at the ceramic wealthy zone with 20 N, 2 m/s, 500 m, and ANOVA analysis revealed that the various zones had a major impact (30.70%) followed by load (28.76%). The worn surface investigation confirmed the production of a stable tribo-oxide layer and revealed the enhanced wear resistance on the wealthy ceramic zone. The microstructural, hardness and wear experiment's findings confirmed the gradient distribution of Si3N4 in the A356 alloy from the exterior to the interior surface, with a maximum in the exterior periphery. [ABSTRACT FROM AUTHOR]

Cold spray (CS) technology has proven a great potential in the production of composite coatings, enabling the production of materials with superior qualities such as enhanced tribological behavior. This study aims to investigate the tribological properties of CS Al-based composite coatings reinforced by quasicrystalline (QC) particles. Two different Al alloys were used as the matrix, AA 6061 and AA 2024, and mixed with Al-based QC particles (Al-Cr-Fe-Cu) at different Al/QC ratios. A room-temperature ball-on-disc test was then used to evaluate the wear resistance of the composite CS coatings in air and compared to those of the non-reinforced Al alloy CS coatings as well as a cast counterpart (AA 6061-T6). We have demonstrated that CS could be employed to produce thick and dense Al-QC composites that can retain up to about 50 wt.% QC reinforcement in the structure. The incorporation of the QC particles increased the wear resistance by a factor of 7. [ABSTRACT FROM AUTHOR]

Reactive sintering of Al-Mg powder mixtures containing 5, 10, 15, and 20 wt.% Mg was used to synthesize lightweight composites reinforced with in-situ formed Al3Mg2 and Al12Mg17 intermetallics. Detailed microstructural investigation and phase analysis were employed to examine the phases in the composites formed at 400 and 450 °C. The creation of particles with the Al12Mg17 cores encapsulated by the Al3Mg2 phase, which was further covered by a continuous aluminum matrix, was observed in the composites synthesized at 400 °C. If the composites were held at 450 °C, the liquid phase appeared at the Al-Mg interface, and as a result, a two-phase mixture was formed. It was the eutectic composed of the Al3Mg2 intermetallic compound and a solid solution of magnesium in aluminum (Al). The introduction of magnesium particles into the aluminum matrix resulted in a decrease in the density of composites, but there was no significant difference in the density of composites sintered at different temperatures. The mechanical behavior of the composites was examined using microhardness and hardness measurements and a room-temperature compression test. The result of using different cooling speeds, with the furnace and quenching in water, was the refining of the grains in the Al3Mg2 + (Al) eutectic, resulting in an increase in microhardness. The increase in hardness of the composites was related to the amount of particles introduced. Sintering at 450 °C and the cooling method influenced the hardness and compressive strength of the composites, which were higher by 10% and 13%, respectively, compared to composites sintered at 400 °C. Tribological tests showed that introducing more and more magnesium particles into the aluminum matrix, followed by reactive sintering, increased the wear resistance. On the other hand, the sintering temperature and cooling conditions had little effect on the wear resistance of the Al-Mg composites. [ABSTRACT FROM AUTHOR]

The present study highlighted the nano-Si3N4 addition effect on microstructural and mechanical characteristics, such as hardness and tensile properties of the dissimilar AA2014 and AA2024 based composite material. The fabricated composites were characterized through Scanning Electron Microscopy (SEM) and X-ray Diffraction (XRD) analysis. The experimental findings revealed that the FSP technique produced a uniform distribution of nano- Si3N4 particles in the aluminum matrix (AA2014 and AA2024), which provided a significant improvement in the mechanical performance of the composite developed after triple tool passes. Fair interfacial reaction layer was identified between nano-Si3N4 and alumnium matrix. The addition of nano- Si3N4 particles in the aluminum matrix composite enhanced the hardness by 21.91% compared to the un-reinforced aluminum matrix composite. Moreover, the tensile strength of the composite was improved by approximately 14.42% in comparison to the base aluminum matrix. However, composite developed in triple tool passes produced a nanocrystalline layer near the surface of the material, which improved the wear resistance of the composite. [ABSTRACT FROM AUTHOR]

Tribological behavior of aluminum (Al) 6061 alloy reinforced with 20% submicron (0.7 μm) alumina (Al2O3) particles was evaluated under dry conditions at temperatures ranging from 25 to 300 °C. Pin-on-disk wear tests were performed with the composite pin sliding against AISI 4041 steel counterface disk at selected loads. Under dry conditions, the wear resistance of the composite was characterized by two regimes, namely, mild and severe wear at all temperatures. However, the critical load for severe wear was found to decrease with increase in temperature, indicating decrease in wear resistance with increase in temperature. The worn surfaces were characterized by abrasion, delamination, and adhesion in mild, transition, and severe wear regions, respectively, at room temperature. However, at elevated temperatures, matrix softening of the composite was found to be dominant mechanism of wear in addition to particulate fracture. [ABSTRACT FROM AUTHOR]

For improving the wear resistance of soft Al substrate by fabricating surface composite, commercial Al metal matrix composite (MMC) SiCp/A356 sheet was cladded onto 1060 Al substrate by friction stir brazing (FSB) process, in which a pinless tool and Zn solder were used to avoid pin wear and to extend bonded width. The MMC/Al (top/bottom) configuration exhibited intimately contacted interface, Al-Zn bond seam reinforced by SiC particles and higher shear strength (70 MPa) due to sufficient dissolution with the aid of torquing action directly on the MMC sheet from the large rotating shoulder. For Al/MMC configuration, excessive softening of the top 1060 Al and indirect micro-shearing on the bottom SiCp/A356 resulted in excessive expulsion of molten Zn, insufficient dissolution, poor wettability and lower shear strength (35 MPa). FSB was able to produce a surface composite layer with large width up to shoulder diameter in air. [ABSTRACT FROM AUTHOR]

This study examines the effects of 2%, 4%, and 6% additions of TiO2 nanoparticles on the wear and mechanical characteristics of Al 5054 alloy reinforcement. The results demonstrate that the addition of TiO2 nanoparticles considerably increases the alloy's tensile and impact strengths. Tensile strength reaches a peak of 221 MPa at 6% reinforcement and it rises gradually as the percentage of TiO2 reinforcement increases. Similarly, impact strength rises with time and, with TiO2 reinforcement, it reaches a maximum of 63 Joules at 6%. Wear analysis using Taguchi-based design determines the optimal combination of composition, disc rotation speed, load, and sliding distance to minimize a given wear rate and friction force. The SEM analysis validates that the composites exhibit enhanced wear resistance due to the uniform distribution of TiO2 nanoparticles. An Artificial Neural Network (ANN) model is also developed to predict the responses, and it achieves an overall accuracy of 83.549%. The mechanical properties and wear resistance of TiO2 -reinforced Al 5054 composites can be enhanced, as it is demonstrated by these results. This information is crucial for material design and optimization across a range of engineering applications. [ABSTRACT FROM AUTHOR]

Microwave Assisted Self-propagating High-temperature Synthesis (MASHS) was used to prepare open-porous MAX phase preforms in Ti-Al-C and Ti-Si-C systems, which were further used as reinforcements for Al-Si matrix composite materials. The pretreatment of substrates was investigated to obtain open-porous cellular structures. Squeeze casting infiltration was chosen to be implemented as a method of composites manufacturing. Process parameters were adjusted in order to avoid oxidation during infiltration and to ensure the proper filling. Obtained materials were reproducible, well saturated and dense, without significant residual porosity or undesired interactions between the constituents. Based on this and the previous work of the authors, the reinforcement effect was characterized and compared for both systems. For the Al-Si+Ti-Al-C composite, an approx. 4-fold increase in hardness and instrumental Young's modulus was observed in relation to the matrix material. Compared to the matrix, Al-Si+Ti-Si-C composite improved more than 5-fold in hardness and almost 6-fold in Young's modulus. Wear resistance (established for different loads: 0.1, 0.2 and 0.5 MPa) for Al-Si+Ti-Al-C was two times higher than for the sole matrix, while for Al-Si+Ti-Si-C the improvement was up to 32%. Both composite materials exhibited approximately two times lower thermal expansion coefficients than the matrix, resulting in enhanced dimensional stability. [ABSTRACT FROM AUTHOR]

Friction stir processing (FSP) is used to enhancing the hardness, tensile strength, corrosion and wear resistance of the substrate by changing the microstructure and through reinforcing the surface with hard-particles. In this paper, the available literatures have been carefully scrutinised and systematically categorised into FSP process and its resulting effects on the different grades of aluminium-based metal matrix composites (AMMCs). The effect of various reinforcements on AMMCs is also discussed. The objective of this paper is to review the various FSPed AMMCs fabricate at different operating conditions under various FSP parameters and summarise their effects on the microstructure and final properties of surface composites. Improvement in mechanical properties, corrosion resistance and wear resistance were observed. Fine grains of 100 nm to 400 nm in size were obtained in AA7075-T6 matrix after multi-pass FSP with rapid cooling. In AA7075/9 wt% TiB2 SCs, the grain size reduces from 335 µm (cast AA7075) to 6.3 µm, UTS increased to ~237%, hardness increased to ~246% and wear rate reduced to ~47% as compared to cast AA7075. This review paper will be helpful to new researchers working in the field of FSP, as it comprises significant knowledge related to AMMCs through FSP. [ABSTRACT FROM AUTHOR]

The mechanical behavior of Al–Fe–Cr aluminum matrix composites strengthened by nanoquasicrystalline and/or crystalline phases was studied in the temperature range of 77–573 K. The strength characteristics and elongation to fracture during tensile tests of Al94Fe2.5Сr2.5Ti1, Al94Fe2Cr2Ti2, Al94Fe2.5Сr2.5Ti0.7Zr0.3 alloys were determined. It was established that the Al94Fe2Cr2Ti2 composite alloy has the highest strength (σb ≥ 3.87 GPa) among wrought aluminum alloys with satisfactory plasticity (elongation to fracture δ ≥ 5% at 293 K) at the temperature of 573 K. Tribological tests have shown that the wear resistance of Al–Fe–Cr aluminum matrix composites is significantly higher in the case of lubrication than when dry friction occurs. In lubrication, the friction force is almost 5 times less as well. The Al94Fe2Cr2Ti2 composite is optimal by the combination of mechanical and tribological properties among the studied alloys due to the strengthening of the aluminum matrix by nanoparticles with both crystalline and quasicrystalline structures. [ABSTRACT FROM AUTHOR]

In this study, the preparation of nanoporous-TiO2-doped Al composites with improved mechanical properties and wear resistance was carried out. For this purpose, nanosized TiO2 structures were first synthesized using the hydrothermal synthesis method. The size distribution, morphology, and chemical structure of the obtained TiO2 particles were investigated by particle size analyzer, SEM, XRD, and FTIR spectroscopy techniques. At the same time, TiO2 structures containing hydroquinone (Hq) at different rates (5, 10, and 15%) were prepared in order to ensure homogeneous TiO2 distribution during the formation of Al matrix composites and to prevent oxidation that may occur during composite casting. TiO2–Al composite structures were obtained by doping the synthesized pure TiO2 nanoparticles and TiO2 nanoparticles containing hydroquinone in different ratios to the Al matrix structure. The obtained composite structures were examined structurally by FTIR and XRD spectroscopy techniques. Then, the thermal properties of the composite structures obtained were examined by TGA analysis. Morphological properties, microstructure, and surface elemental distribution of the composite structure were investigated by SEM and EDX techniques. The abrasion properties of the obtained TiO2 added Al composite structures were investigated using SiC papers (200–400–600 and 800–1200 mesh). As a result, it was observed that the doped TiO2 nanoparticles reduced surface deformation during abrasion. [ABSTRACT FROM AUTHOR]

In this paper, SiCp aluminium matrix composites were used as the matrix, and AlSi10Mg powder, which has a relatively similar coefficient of thermal expansion to that of the matrix, was used to prepare laser cladding Al-based coatings. The results show that the optimal process parameters are P = 4400 W, Vf = 11.3 g·min−1, and VS = 1800 mm·min−1, and, although the hardness of the coatings is lower than the hardness of the substrate, it reduces the generation of defects such as cracks and porosity. With the increase in WC reinforced phase and the hardness of the coatings, wear resistance increases, the granular cytocrysts are transformed into rod-like cytocrysts, and at the same time generate the dendritic crystals, and the undergo grain refining and generate the new phases such as Al4C3, Al4SiC4. There is no obvious defect in AlSi10Mg + 40%WC coatings, the macro morphology of the coatings is good, there is no spalling in the friction wear morphology, and the wear resistance is excellent, but there are obvious cracks and obvious spalling in the coatings of AlSi10Mg + 60%WC. Compared to the matrix hardness of 171.61 HV, the hardness of the 20%WC cladding layer increased by a factor of 1.06, while the hardness of the 40%WC cladding layer increased by a factor of 1.65 and that of the 60%WC cladding layer increased by a factor of 1.8. In terms of wear, compared to a substrate wear amount of 9.36 mg, the wear for the 20%WC cladding layer was reduced to 6.13 mg (34.5% less than the substrate), for the 40%WC cladding layer it was reduced to 4.58 mg (51.06% less than the substrate), and for the 60%WC cladding layer it was reduced to 7.35 mg (21.47% less than the substrate). The quality of the coatings decreases although the hardness is higher than that of AlSi10Mg + 40%WC. The comprehensive performance of AlSi10Mg + 40%WC coatings is optimal. [ABSTRACT FROM AUTHOR]

Aluminium MMCs are among the many metal composites and are regarded as progressive engineering materials in numerous industries because of their advantages compared to standard aluminium alloy. Among the reinforcements in MMCs, ceramic particles are preferred for their superior wear resistance, temperature resistance, and adhesion to their matrix, making them a popular choice. This research work has been carried out to synthesise ceramic particle-reinforced aluminium metal matrix composites and to evaluate their tribological properties at different temperatures (50–300℃). Al2618 alloy was selected as the matrix, and boron carbide (B4C) and graphite (Gr) were selected as reinforcements. Hybrid composites are prepared through stir casting by varying the wt.% of B4C and Gr reinforcement particles with a ratio of 3:2. Microstructural observation shows the uniform distribution of B4C and Gr particles throughout the matrix without any agglomeration, and it also exhibits excellent scanning electron microscope (SEM). X-ray diffraction analysis (XRD) was performed to verify the presence of different constituents in the developed material. Samples S4 (Al 2618 + 12 wt.% B4C—8 wt.% Gr) and S5 (Al 2618 + 15 wt.% B4C—10 wt.% Gr) exhibit enhanced wear resistance (16.45%) due to the incorporation of a higher quantity of Gr solid lubricants alongside B4C within the temperature range of 50 to 300℃. The thickness and stability of the glazed layer exhibited adequate resistance to wear. [ABSTRACT FROM AUTHOR]

Marine biofouling is a worldwide issue that has aroused great concern in scientific community. Herein, a micron-laminated Cu-Al2O3 composite coating was facilely obtained via plasma spraying of Cu/Al2O3 powders to achieve eco-friendly and long-lasting antifouling performance along with superior wear resistance. The microstructure, long-term antifouling performance, and wear behavior of the Cu-Al2O3 coatings as a function of Al2O3 content were systematically investigated. Results indicated that the Cu-Al2O3 coating exhibited controlled slow copper ions leach rate of approximately 5 times lower than that of the Cu coating, promoting eco-friendly and long-lasting antifouling protection. Additionally, the copper ions leach rate from the Cu-Al2O3 coatings decreased as the Al2O3 content increased, which was mainly related to the Cu amount involved in dissolution reaction. Long-term antifouling efficiencies against bacterial survival and algae settlement for the Cu-Al2O3 composite coatings with 32.1-66.2% Al2O3 were higher than 90%. Furthermore, the Cu-Al2O3 coatings exhibited superior wear resistance by the strengthening of Al2O3. Continuous tribolayer containing trapped Al2O3 particles formed on worn surface was responsible for the excellent wear resistance of Cu-Al2O3 coatings. The outstanding comprehensive performance of Cu-Al2O3 coating combining long-lasting and eco-friendly antifouling ability and remarkable wear resistance gives clear insight into its potential applications in marine antifouling field. [ABSTRACT FROM AUTHOR]

Aluminium matrix composites offer a combination of properties such as lower weight, higher strength, higher wear resistance and many more. The stir casting process is easy to use, involves low cost and is suitable for mass production compared to other manufacturing processes. An in-depth look at recently manufactured aluminium matrix composites and their impact on particle distribution, porosity, wettability, microstructure and mechanical properties of Al matrix composites have all been studied in relation to stirring parameters. Several significant concerns have been raised about the sample’s poor wettability, porosity and particle distribution. Mechanical, thermal, and tribological properties are frequently studied in conjunction with variations in reinforcement proportion but few studies on the effect of stirrer blade design and parameters such as stirrer shape, dimensions and position have been reported. To study the effect of stirrer blade design on particle distribution, computational fluid dynamics is used by researchers. Reported multiphysics models were k-ε model and the k-ω model for simulation. It is necessary to analyse these models to determine which one best solves the real-time problem. Stirrer design selection and analysis of its effect on particle distribution using simulation, while taking underlying physics into account, can be well-thought-out as a future area of research in the widely adopted stir casting field [ABSTRACT FROM AUTHOR]

The present investigation highlights the development of high-performance materials in the construction materials industry, with a special focus on the production of aluminium matrix composites (AMCs) containing titanium carbide (TiC) particles. The stir casting method with ultrasonic assistance was employed to enhance the mechanical and tribological properties. ASTM standards were employed to evaluate the influence of TiC particles on density, hardness (VHN), ultimate tensile strength (UTS), and wear resistance at various TiC weight fraction percentages (0.0 wt.%, 2.0 wt.%, 4.0 wt.%, 6.0 wt.%, and 8.0 wt.%). Field emission scanning electron microscopy (FESEM) and X-ray diffraction (XRD) analysis were performed to analyse the microstructural changes and elemental phases present in the synthesised composite. Results revealed that the incorporation of 8 wt.% TiC reinforcement in the metal matrix composites demonstrated significant improvements compared to the base alloy. In particular, a substantial enhancement in hardness by 32%, a notable increase of 68% in UTS, and a significant 80% rise in yield strength were observed when contrasted with the pure aluminium alloy. The tensile fracture analysis of the specimens revealed the presence of dimples, voids, and cracks, suggesting a brittle nature. To assess the wear characteristics of the composites, dry sliding wear experiments were performed using a pin-on-disc wear tester. Incorporation of TiC particles resulted in a lower coefficient of friction than the base alloy, with the lowest friction coefficient being recorded at 0.266 for 6 wt.% TiC, according to the data. FESEM and energy-dispersive X-ray spectroscopy (EDXS) were used to examine the surfaces of the worn pin. Overall, the inclusion of TiC reinforcement particles in the matrix alloy greatly enhanced the wear resistance and friction coefficient of the Al-6TiC composites. Ploughing and adhesion under lower loads and delamination under higher loads were the wear mechanisms observed in the wear test. [ABSTRACT FROM AUTHOR]

This study focuses on the synthesis of TiC-TiB2/Fe coatings with varying amounts of aluminum (Al) using tungsten inert gas (TIG) cladding and investigates the impact of Al addition on microstructure refinement and performance enhancement of the coatings. The coatings were prepared on a mild steel substrate using TIG cladding. X-ray diffraction (XRD) analysis revealed the presence of TiC, TiB2, AlxTi, and AlxFe phases in the coatings. Scanning electron microscopy (SEM) images showed that the addition of Al improved the microstructure, reducing defects and enhancing the distribution of reinforcing phases within the coatings. The particle size of the reinforcing phases was significantly refined by the addition of Al. The micro-hardness of the coatings was significantly higher than that of the substrate, with the maximum micro-hardness of the coating reaching 955.5 ± 50.7 HV0.1, approximately six times that of the substrates. However, excessive Al addition led to a reduction in hardness due to a decrease in the quantity of hard phases. The wear tests showed that all the coatings had lower wear loss compared to the substrate material, with the wear loss initially decreasing and then increasing with the increasing Al content. Samples with a 28.57 wt.% Al addition exhibited the best wear resistance, with approximately 16.8% of the wear volume loss compared to mild steel under the same testing conditions, attributed to the optimal combination of reinforcement phase quantity and matrix properties. [ABSTRACT FROM AUTHOR]

The Al–K2ZrF6–KBF4 system, (ZrB2 + Al3Zr)/AA6016 aluminum matrix composites were successfully synthesized in situ under different external fields, and ZrB2 + Al3Zr dual-phase reinforced particles were successfully synthesized in the composites by XRD. The morphology of the dual-phase particles was observed by SEM and EDS, and it was found that the primary function of the external ultrasonic field was to break the grain clusters and reduce the particle size; the position of the external magnetic field was to promote the in-situ reaction and improve the synthesis rate of the particles. The acoustic-magnetic coupling can play the role of two external areas at the same time. Through the hardness test, tensile test, friction and wear test, the experimental results show that the ultimate tensile strength and elongation of the composite material under the action of acoustic-magnetic coupling are 181.4 MPa and 24.5%, an increase of 51.3% and 102.5% over the same period of last year; the microhardness of the material under the action of acoustic-magnetic coupling increased to 71.9 HV, an increase of 43.8% compared with the matrix. The grains of the material through the acoustic-magnetic collar is more refined, with a size of 74.2 μm, and the dimensions of ZrB2 and Al3Zr are smaller. A single ultrasonic field reduces the particle size, increasing the friction coefficient and reducing the wear resistance; a single magnetic field promotes the synthesis of particles, increases the number of particles, and improves the wear resistance to a certain extent. The effects of magnetic field and ultrasonic coupling on the distribution and morphology of composites and their properties were investigated. [ABSTRACT FROM AUTHOR]

The subject of the work are modern composite materials with increased wear resistance intended for elements of machines operating in difficult conditions in the construction and mining industries. The study determined the effect of zone reinforcement of GX120Mn13 cast steel with macroparticles (Al2O3 + ZrO2) on the corrosion resistance and abrasion wear of the composite thus obtained. SEM studies have shown that at interface between two phases, and more precisely on the surface of particles (Al2O3 + ZrO2) a durable diffusion layers are formed. During the corrosion tests, no significant differences were found between the obtained parameters defining the corrosion processes of GX120Mn13 cast steel and GX120Mn13 with particles (Al2O3 + ZrO2) composite. No intergranular corrosion was observed in the matrix of the composite material, nor traces of pitting corrosion at both phases interface. This is very important in terms of tested material’s service life. Reinforcement of cast steel with particles (Al2O3 + ZrO2) resulted in a very significant improvement in the abrasion resistance of the composite – by about 70%. After corrosion tests, both materials were subjected to further operational investigations. These examinations consisted in determining the impact of corrosion processes on the durability of the composite in terms of abrasion. The obtained results indicate that corrosion processes did not significantly deteriorate the wear resistance of both the cast steel and the composite. [ABSTRACT FROM AUTHOR]

In this study, the microstructure and sliding wear characteristics of the as-cast and SiC-reinforced ZK60 magnesium alloys were investigated. The microstructural evaluation confirmed nearly dense microstructure with homogeneous dispersion of the SiC particles within the matrix. The wear performance of the as-cast alloy and ZK60/SiC composites with 10 wt.% and 20 wt.% SiC were investigated by the pin-on-disk method using a 52,100 steel pin with 5 mm diameter at different applied loads in the range of 10–160 N. The results revealed that oxidation was the dominant wear mechanism at low loads, resulting in the slight wear rates of the composites and as-cast alloy. However, a rapid increase in the wear rate occurred by increasing the applied load to > 40 N owing to the change in wear mechanism from oxidation to abrasion and delamination. An obvious difference between the wear resistance of composites and unreinforced alloys was observed at high loads. The SiC particles in the composites strengthened the alloy and prohibited the crack nucleation and propagation at high loads. Moreover, by increasing the weight percentage of the reinforcement, the wear resistance of composite was enhanced because of the enhancement of composite hardness. [ABSTRACT FROM AUTHOR]

Aluminum (Al)–aluminum–carbon nanotube (Al–CNT) dual-matrix (DM) composites are a novel class of nanocomposite materials that combine the ductility of the Al matrix with the hardness and wear resistance of the Al–CNT composite and thus can offer a unique combination of properties that make them suitable for a wide range of wear applications such as cutting tools, bearings, brake pads, wear-resistant coatings, etc. However, the specific properties of the DM Al–(Al–CNT) composite will depend on several factors related to the material's composition and the friction conditions. This study investigates the wear behavior of DM Al–(Al–CNT) composites consisting of a primary matrix of soft aluminum in which milled hard particles of (Al–CNT) are dispersed as affected by five parameters: (1) wt.% CNT in the reinforcement particles, (2) mixing ratio between the reinforcement particles and the soft Al matrix, (3) sliding speed, (4) applied load, and (5) distance. The experimental design used a Taguchi fractional factorial orthogonal array (OA) L27 to reduce the number of experiments, and analysis of variance (ANOVA) was used to determine the significance and to model the effect of each control parameter. Results showed that the wear rate could be reduced by up to 80% by tailoring the composition and controlling the friction conditions. It was found that the mixing ratio significantly impacts the wear behavior of DM Al–(Al–CNT) composites. A mixing ratio of 50% and a CNT content of 3 wt.% at the lowest applied load gave the lowest wear rate and coefficient of friction. Scanning electron microscopy investigations showed fragmentations in the reinforced matrix at higher loads and mixing ratios, which negatively impacted the wear behavior. Our findings confirm that DM Al–(Al–CNT) composites are promising for wear applications. However, the wear behavior depends on the composition and microstructural design of the composite, which needs to be carefully studied and understood. [ABSTRACT FROM AUTHOR]

Due to the high hardness and wear resistance of SiC particles, severe tool wear was prevalent when cutting SiC particles-reinforced aluminum matrix (SiCp/Al) composites with traditional machining methods. This paper aims to comprehensively investigate the feasibility of laser cutting SiCp/Al composites with high volume fraction of SiC particles under different processing parameters. Surface morphology and cross-section characteristics were analyzed for further understanding laser–SiCp/Al composite interaction/removal mechanisms. Results showed that high specific energy was the most significant factor affecting surface quality during laser cutting SiCp/Al composites, and the threshold value was ~ 90 J/mm for successfully cutting through 1.0-mm-thick samples and ~ 450 J/mm for 5.0-mm-thick ones. Stripes, re-solidified materials, dross and spatters were typical defects observed during high-power fiber laser cutting SiCp/Al composites with high volume fraction. The experimental results can most likely bring new knowledge to understand the characteristics of thermal defect and heat conduction following high-efficient fiber laser cutting SiCp/Al composites and also provide data for applying high-power fiber laser in advanced automotive/aerospace industry for future applications. [ABSTRACT FROM AUTHOR]

In this work, friction stir processing (FSP) was used to successfully embed boron carbide (B4C) particles into an aluminum matrix (AA6061-T6). Four specimens of aluminum 6061 composite reinforced with 4%, 6%, 8%, and 10% volume fraction of B4C were manufactured. The effects of B4C particles volume fraction on microstructure, mechanical and wear properties are investigated. The microstructural investigations demonstrated that a rise in the volume % of reinforcement greatly decreased the matrix grain size. The manufactured AA6061-T6 loaded with B4C surface composites demonstrated homogeneous B4C particle dispersion, with no significant particle clustering in the stir zone. In addition, it was established that increasing the volume fraction of B4C particles promoted grain refinement, increased hardness, and tensile strength. X-ray diffraction (XRD) was used to identify the reinforcement dispersion. For AA6061-T6 with 10% B4C particles, a maximum hardness value of 163 HV was obtained in the stir zone. Maximum yield strength of 165 MPa and ultimate tensile strength of 220 MPa were attained by AA6061-T6 with 10% B4C particles, which is an improvement of 21% over the specimen FSP without reinforcement. The strengthening of the grain refining was attributed for the increase in hardness and strength. The ductility was reduced by the incorporation of more B4C particles. Comparing the surface composite loaded with B4C to unreinforced friction stir processing and AA6061-T6 as received, it demonstrated superior wear resistance. [ABSTRACT FROM AUTHOR]

The mechanical behavior of AA7068–4 wt.% ZrO2p composite was investigated at the cast and thermally treated (T6) conditions. The wear and friction behaviors were also examined under varying sliding distances (0–5000 m), paying special accentuation to the response parameters. The heat-treated 4% ZrO2p composite exhibited the highest ultimate tensile strength of 518 MPa, the least ductility of 7.48%, and the maximum hardness of 180 HV. The composite displayed improved wear resistance over the alloy irrespective of the condition. The friction coefficient and temperature rise due to frictional heating exhibited a revered trend. It was also observed that the induction of ZrO2p had effectually hindered the degree of subsurface deformation. The evolution and stability of mechanically mixed layer, oxide layer, cracking and deformed subsurface were detected as the operative wear mechanisms. [ABSTRACT FROM AUTHOR]