Hybrid Metal Matrix Composites Research Articles

Al6061-Basalt and Zircon Hybrid composite Material Corrosion Resistance in Acid Media

The present investigation is an attempt made to develop Al6061/Basalt/Zirconium oxide Hybrid Metal Matrix Composites (MMCs) by liquid metallurgy technique (stir casting) and to study the wear properties of Al6061/Basalt/Zirconium oxide reinforced hybrid metal matrix composites. The composite is prepared by using Liquid Metallurgy Route (Stir Casting Technique), although other processing technique such as powder metallurgy delivers better mechanical properties in MMCs, Liquid state has some significant focal points, for example, better matrix molecule holding, simpler control of matrix structure, ease of handling, closer to net shape and wide choice of material. Al6061 is taken as a base material (matrix) and Basalt (1– 10%) and Zirconium oxides (2%) are used as reinforcements. Corrosion analysis for Aluminum Metal Matrix Composites (MMCs) was done in acid (HCl) media at room temperature & different time intervals. The results were tabulated & it was found that the MMC containing 4% basalt underwent maximum corrosion at room temperature. SEM is done for all the samples the results are tabulated.

A Study on Micro-structure, Hardness and Optimization of Wear Characteristics of Al6061/TiB2/CeO2 Hotrolled MMCs using Taguchi Method

Aluminium composites are extensively used in several industrial applications. The production of Metal Matrix Composite (MMCs) with varying wt. % of reinforcement/s leads to enhancement of wear and mechanical behavior. In the present work, the varying wt. % of TiB2 and constant wt. % of CeO2 particulates were reinforced in Al6061 alloy to manufacture hybrid Al MMCs by Vortex (Stircasting) technique. Developed hybrid MMCs were hotrolled at 515°C of temperature. Hardness of hybrid MMCs was evaluated by using hardness test rig (Vickers). Result revealed that the hardness strength of developed hybrid MMCs increased with increase of the reinforcement content. The rate of wear of developed hybrid MMCs was evaluated by using Pin on Disc wear test. Test trials were conducted according to Taguchi technique. L27 array was implemented for evaluation of data. Effect of varying factors on the rate of wear and COF was analyzed by applying ANOVA (Analysis of Variance) method. ANOVA outcomes showed that the reinforcement content had a more significant impact on wear behavior and COF of the MMCs. Finally, L27 array outcomes were verified through confirmation experiments. A wear fractography outcome shows the internal fractured structure of a wear specimen which was studied using a SEM.

Dry Sliding Wear Performances of AA5052 Hybrid Composite Brake Disc Materials Reinforced With In Situ Synthesized TiC and Multi-Walled Carbon Nanotube

Abstract In this research, aluminum alloy AA5052-based hybrid metal matrix composites (MMCs) were fabricated using in situ synthesized titanium carbide (TiC) and ex situ multi-walled carbon nanotube (MWCNT) as reinforcements using the liquid metallurgy route. The wear characteristics of the aluminum hybrid MMCs were analyzed under the synergistic effects of TiC and multi-walled CNT. Pin-on-disc wear setup was utilized for the experimental investigation where the hybrid composite is considered as the disc, and the traditional brake pad material is treated as the pin. The parameters, i.e., sliding distance, applied load, sliding velocity, and reinforcement content, are treated as inputs, whereas the wear-rate and coefficient of friction are considered output variables for the tribological experimentation. The influence of various input process parameters on the tribological behavior of the fabricated samples was investigated. The plastic deformation attained by the base alloy exhibited delamination, which indicates adhesive wear, whereas the composites exhibited abrasive nature as analyzed from the wear surface morphology. The wear debris was characterized by flake-sized, corrugated, and oxidized by the microstructural study.

Physical and mechanical behavior of aluminum-magnesium alloy matrix hybrid composite fabricated through friction stir consolidation process

Nowadays metal matrix composite materials are preferable in automotive and aerospace industries due to their mechanical properties and essentially attractive strength to weight ratios. However, their availability in use is limited because of their manufacturing method difficulty and process extravagancy. The aim of this research was to fabricate metal matrix hybrid composite through a novel approach thermo-mechanical method called friction stir consolidation (FSC) process. XRD result witnessed the presence of SiC, ZrO2, and AZ61 alloy phases. Different compositions of AZ61, SiC, and ZrO2 powder were taken into consideration and the progression of the FSC process were examined through properties of compressive strength, hardness, density, and porosity. For instance, the compressive yield strength of composition 85%Vol. of AZ61, 10%Vol. of ZrO2, and 5%Vol. of SiC accounts 164.2 MPa with an acceptable 2.2451 g/cm3 and 0.593% density and porosity respectively. However, when the strength to weight ratio was taken into consideration, 95%Vol. of AZ61, 2.5%Vol. of ZrO2, and 2.5%Vol. of SiC composition attained highest strength to weight ratio value. Additionally, the compressive yield strength value increased directly proportional with the ZrO2 volumetric composition. Likewise, the fractured surface of sample acquired highest strength to weight ratio was examined through SEM Fractography analysis.

Synergetic Effect of Gr-B4C Reinforcement on the Structural and Mechanical Properties of AA6351 Hybrid Metal Matrix Composites

The purpose of this study is to investigate the effects of Graphite (Gr)-Boron Carbide (B4C) reinforcement particles on the mechanical characteristics of an aluminium-based hybrid metal matrix composites. Hybrid metal matrix composites (MMCs) were prepared by adding different proportions of Gr and B4C (0.5–0.5, 1.0–1.0, 1.5–1.5, and 2.0–2.0 wt%) through liquid metallurgy (stir casting) route. The phase, microstructure, EDS, density, hardness, tensile strength of fabricated samples were studied. Through X-ray diffraction analysis, it was established that there was a transitional stage of development between the matrix and reinforcement particles due to interfacial bonding. Furthermore, scanning electron microscopy results indicate a consistent dispersion of reinforcement particles within the aluminium matrix up to the 1 wt% Graphite and 1 wt% B4C. As the proportion of reinforcement increased, a decrease in density was observed, with the lowest density as 2.62 g cc−1 in the sample containing 2 wt% Graphite and 2 wt% B4C. The best mechanical characteristics of the fabricated hybrid metal matrix were observed with 1 wt% Graphite and 1 wt% B4C, with a hardness of 82 HRC, impact strength of 32 Joules, and an engineering ultimate tensile strength of 134.3 MPa.

Mechanical and wear characteristics of (Al7075/SiC/Gr/Zr) hybrid metal matrix composites using ultrasonic assisted stir casting process

Mechanical and wear characteristics of (Al7075/SiC/Gr/Zr) hybrid metal matrix composites using ultrasonic assisted stir casting process

Corrosion behavior and tribological-microstructural characterization of Al/ZrO2-Gr hybrid composite fabricated via Friction Stir Processing

The present study investigates the microstructural evolution, tribological properties, and corrosion behavior of hybrid metal matrix composites reinforced by a combination of graphite (Gr) and zirconia (ZrO2) particles fabricated by Friction Stir Processing (FSP). To do so, microstructural characterization was carried out by optical microscopy (OM) and electron backscatter diffraction (EBSD) analysis. In addition, pin-on-disk, microhardness measurement, potentiodynamic polarization, and electrochemical impedance tests were conducted to evaluate the tribological and corrosion behavior of the samples. Results showed that employing four passes of FSP led to significant grain refinement in stir zones because of dynamic recrystallization (DRX), particle-stimulated nucleation (PSN), and Zener pinning effect. Furthermore, the EBSD results illustrated that the average grain size area has significantly decreased from ∼115 µm2 in the only FSP-treated specimen to ∼1.2 µm2 in the hybrid composite. Also, the presence of the secondary phase particles caused an increase in the fraction of the high-angle grain boundaries (HAGBs) compared to the only FSP-treated specimen. The results of the pin-on-disk test revealed that the wear resistance improved in the particle-reinforced composites and, on the other hand, decreased in the FSP-treated sample compared to the base metal (BM). Furthermore, the lubricant effect of the Gr particles contributed to a pronounced reduction in the coefficient of friction (COF) and weight loss in the Gr-containing composites such that the COF of the hybrid composite and Gr-reinforced mono-composite dramatically decreased by ∼0.52 and ∼0.37, respectively. The corrosion behavior of the FSP-treated sample demonstrated better resistance compared to the BM. In addition, the particle-reinforced composites exhibited better corrosion resistance than the FSP-treated sample and BM, especially the Al/Gr mono-composite which had the minimum corrosion rate and the most positive pitting potential (Epit), making it the most pitting-resistant sample in comparison to other specimens.

Experimental Analysis of Aluminium Hybrid Composite with Various Operating Conditions

This present study deals with the fabrication of Al7075/B4C/HBN metal matrix hybrid composite and investigation of its tribological and mechanical behaviour. The aluminium alloy was reinforced with Hexagonal boron nitride (HBN) with various weight fraction (0%,2%,3%,4%) by keeping Boron carbide (B4C) constant at 3%. Stir casting process was used for the fabrication of the composite. Wear experiment was conducted on pin-on-disc tester using four process parameters such as applied load (10N, 20N, 30N and 40N), sliding velocity (1m/s, 2m/s, 3m/s, 4m/s), temperature (25oC, 50oC, 100oC, 150oC) and percentage of reinforcement (0,2,3,4 HBN). The results indicated that the mechanical properties of the composite material were reduced at high temperatures. Hardness of the composites increases while increase the wt % of HBN. Hardness is minimum at 3rd composition. However, at high temperatures and humidity levels, some debonding was observed, which could reduce the mechanical properties of the material. Overall, the experimental analysis highlights the importance of considering the operating conditions when designing and using aluminum hybrid composites for various applications.

Experimental investigations of AA6061/Al2O3/WC/SiC hybrid metal matrix composite fabricated by two step stir casting

ABSTRACT Hybrid metal matrix composites have emerged as an epicentre of material research due to their vast applications and a wide array of reinforcement combinations. In this experiment, two-step stir casting method had been used to fabricate hybrid aluminium 6061 metal matrix composites. The micro-structural and mechanical evaluation (density measurement, impact, tensile, hardness, and flexural) of the fabricated aluminium (AA6061) hybrid metal matrix composite had been performed. The reinforcements used were Al2O3 (3 wt.%), RHA (2 wt.%), WC (2 wt.%), and SiC (5 wt.%, 10 wt.%, 15 wt.%, 20 wt.%). The mechanical properties had been found to improve with increasing wt.% of SiC. The maximum experimental density (2999.2 Kg/m3), impact energy (6 J), tensile strength (130.15 N/mm2), hardness (35 HRA), and flexural load (6720 N) had been obtained with 20 wt.% SiC reinforcement. The presence of reinforcements (Al2O3, RHA, WC, SiC) and their uniform distribution in the Al6061 matrix was confirmed by micro-structural analysis. Other surface morphological information like agglomeration of less soluble alumina and presence of dendrite structures at higher SiC concentration were also revealed. Further, the observations from this investigation have been compared with already existing literature. In conclusion, prospects for future research have also been explored.

Mechanical and tribological assessment of AA7075 reinforced Si3N4/TaC/Ti hybrid metal matrix composites processed through stir casting process

ABSTRACT In the present research work, microstructural, mechanical and tribological aspects of Aluminium alloy (AA) 7075 reinforced with Titanium (Ti), Tantalum Carbide (TaC), and Silicon Nitride (Si3N4) ceramic particles were explored by utilising stir casting. Mechanical attributes like compression, tensile, hardness and flexural were evaluated. Dry sliding wear experiments at both room (30°C) and elevated atmospheric (60°C & 120°C) conditions were conducted to investigate the wear performances. Microstructural analyses reveal homogeneous distribution of reinforcements in the matrix along with good interfacial bonding with negligible amount of agglomeration. Considering the effect of hard ceramic materials in the matrix alloy tensile, compression, flexural and hardness of the developed MMCs found to be improved when compared with base alloy. Finer grains restrict the dislocation movement due to the Orowan strengthening mechanism of the developed hybrid MMCs. As the force enhances from 20 N to 40 N, the rate of wear for AA7075 reinforced with 0.75 wt% TaC, 6 wt% Si3N4, and1 wt% Ti was found to be minimum. Taguchi and Analysis of Variance (ANOVA) were performed to acquire the optimum process and dominating parameters. Regression analysis showed the relationship between the output and input control factors.

Fabrication and Thermal Analysis of Hybrid A356 Aluminium Metal Matrix Composites Prepared by Stir Casting Process

Background: Electronic packaging makes use of hybrid A356 aluminium alloy MMCs (matrix metal composites). Enhanced endurance limit, increased production and energy, low maintenance cost, and benefits to the environment, such as reduced noise and airborne pollutants, are among the features that are recommended to be evaluated. Objective: This study aimed to analyze the thermal properties of A356 aluminium alloy with graphite (Gr) and boron carbide (B4C) hybrid metal matrix composites. For this purpose, the A356 hybrid composite was primed by the stir casting process with the addition of 5 wt % and 10 wt % of Gr and B4C reinforcements. In general, A356 hybrid composite material thermal analysis is crucial for electrical equipment. Methods: The liquid-in-filtration method was used to create the hybrid composites, which were then tested thermally for parameters, like melting point, thermal diffusivity, and thermal coefficient of expansion. The thermocouple sensor of a calorimeter was used to examine the disparity in the composites. A thermal analysis tool called TGA was used to visually represent the relationship between a material's weight and temperature. Results: The temperature was found to be 300oC at the 0.411 W/g maximum heat flow rate. Thermal conductivity is the ratio of the temperature difference divided by the area of the heat transfer from one substance to another. The thermal coefficient of expansion illustrates how a material's dimensions and weight change as temperature increases. Conclusion: The proportion of the weight of the hybrid composites was found to fall with a rise in the temperature. The melting point curve of the composites demonstrated a little increase in temperature to be accompanied by a sharp increase in heat flow.

Experimental modelling and optimisation of electrochemical surface grinding of hybrid metal matrix composite

ABSTRACT The demand of hybrid-metal-matrix composites (HMMCs) is rising continuously in various industries such as aerospace, automobile and biomedical. Therefore, effective machining of HMMCs is essential for their productive utilisation. However, machining processes are usually not feasible for shaping this composite due to inherent properties of matrix and reinforcing material, and melting of reinforcement particles. In the present work, a hybrid Electro-Chemical Surface Grinding (ECSG) setup has been developed by combining the Electro-Chemical Machining and Mechanical Grinding action. The process applied on Al-SiC-Gr composite, which is a key member of HMMC family. It is a better alternative for many parts like piston and piston ring in automobile industries. Central composite design-based Response Surface Methodology has been used for experimental modelling, response prediction and optimisation. The effects of significant control factors such as applied voltage, electrolyte concentration, wheel speed, table speed and electrolyte flow rate on material removal rate (MRR) and surface roughness (SR) have been studied. The results revealed that electrolyte concentration and applied voltage are most significant factors for both MRR as well as SR. Genetic algorithm-based optimisation results confirm 45% and 38% improvements in MRR and surface finish.

Wear and friction (Tribological) characteristic of aluminum based metal matrix hybrid composite: An overview

The hybrid composites are a new class of materials for tribological applications that encouraged many researchers to develop hybrid composites. The mechanical properties and tribological of Al based matrix composites enhances the use of mono ceramic as a reinforcement. In hybrid composites the properties of more than one suitable kind of reinforcements is to be exploited to make better composites for various tribological applications. This paper gives an overview about wear and friction (tribological) properties of hybrid composites and its development.

Correlation of Structural and Mechanical Properties for Ultrasonically Stir Casted Al6061 Reinforced SiC-AlN Hybrid Metal Matrix Composites

In our current investigation, Al6061-SiC-AlN composites were manufactured using the ultrasonic stir casting method. As reinforcement, silicon carbide (SiC) and aluminium nitride (AlN) [both 3 percent and 6 percent by wt.] were used to provide mechanical properties including tensile, compressive, and hardness. Al6061-SiC-AlN hybrid composite samples’ tensile strength, compressive strength, and hardness were measured. Al6061-SiC-AlN hybrid composites’ tensile, compressive, and hardness properties are calculated and compared to those of the matrix i.e. Al 6061 alloy. The tensile strength, compressive strength, and hardness all rose from 328 to 385 MPa, 145 to 178 MPa, and 302 to 724 VHN, respectively, with the addition of SiC and AlN nano-reinforcements. The suggested composite is compared to unreinforced Al6061 in terms of density and mechanical qualities such ultimate tensile strength, yield strength, impact strength, hardness, and wear characteristics. The results of the experimental examination showed that the produced hybrid composite, which contains 20% of the total reinforcing material, has no appreciable increase in impact strength but displays high hardness, high yield strength, and low wear rate.

Fabrication and experimental investigation on mechanical properties of AL7075/SiC and crab shell powder hybrid metal matrix composites

The present review describes, in order to meet the need for service conditions from various applications like aircraft industry, automobile industries, etc., offers high strength materials. Therefore an effort was undertaken to work on improving the mechanical characteristics of Al7075 alloy composites with varied weight ratios of (5%, 10%, and 15%) Silicon carbide, which have been cast using the process of stir casting. In the prepared samples, the 10% of SiC reinforced metal matrix composite exhibited the best results compared to the other samples. For the evolution of aluminum metal matrix composite into a hybrid metal matrix alloy of Al7075-10%SiC-Crab shell powder with varied weight percentages (3%,6%,9%), samples and supplement test data were gathered. The mechanical properties of SiC and CSP reinforced composite specimens such that tensile strength was increased with increasing Wt % of SiC and CSP, percentage of elongation reduced with increasing % of SiC and CSP. The hardness of the composite increased with increasing reinforcement content of the matrix material approaching the base material. So, 10%SiC and 9% CSP reinforced composite is the best composite material compared to other composites.

Corrosion behaviour of SiC and Al2O3 reinforced Al 7075 hybrid aluminium matrix composites by weight loss and electrochemical methods

The corrosion study of Al 7075 hybrid metal matrix composites reinforced with equal weight percents (2.5, 5, 7.5, and 10) of silicon carbide and aluminium oxide is investigated in the present work by weight loss and electrochemical methods. In this study, composite specimens prepared by the squeeze casting technique were analyzed at room temperature to estimate the rate of corrosion in a 3.5% NaCl solution for various intervals using the weight loss method. As a consequence, a hybrid Al7075 composite reinforced with 10% SiC and 10% Al2O3 had a lower corrosion rate of 0.9997 mmpy than pure Al7075, which had a maximum corrosion rate of 3.4481 mmpy. The corrosion rate of hybrid composites is determined by the tafel polarization method and the electrochemical impedance spectroscopic method. These experiments showed that the corrosion rate of the hybrid metal matrix composite Al7075 + 10% SiC +10% Al2O3 was 0.630 mmpy less than that of the monolithic 7075 alloy. The corrosion morphology behaviour of the Al 7075 and their hybrid composite samples is observed by SEM. The SEM micrographs implied that SiC and Al2O3 reinforcements with the matrix alloy produced good interfacial and intermetallic bonding and hence decreased the corrosion rate.

Influence of hybrid reinforcements on the mechanical properties and morphology of AZ91 magnesium alloy composites synthesized by ultrasonic-assisted stir casting

In the present study, AZ91 magnesium alloys reinforced with a fixed weight fraction of aluminium oxide (Al2O3: 1.5 wt%) and titanium di-boride (TiB2: 1, 3, and 5 wt%) particle hybrid metal matrix composites were developed using the stir casting method assisted with ultrasonic agitations. The microstructural analysis reveals that the structure of monolithic alloy is made up of α-Mg grains with evenly distributed β-Mg17Al12 intermetallic secondary phases near the grain boundaries. Incorporating hybrid reinforcements into the matrix alloy decreases the average grain size and also leads to the breakdown of the β-Mg17Al12 phase from a rounded shape to sharp needle-like profiles. The micro-hardness, ultimate tensile strength, and impact strength outcomes revealed a direct correlation with varying TiB2 particulate contents, the peak values of which have been achieved with the addition of 3 wt% of TiB2 particulates with AZ91 + 1.5 wt% Al2O3 hybrid composite.

Tribological properties of novel Al 7075(T6)-SiC-crumb rubber-MoS2-based hybrid composites: An experimental approach towards green revolution

In the present study, an experimental approach is conducted for analyzing the tribological attributes of the novel green hybrid metal matrix composites fabricated by an advanced vacuum-sealed bottom pouring stir casting comprised of Al 7075(T6) as a base metal doped with three distinct reinforcements as silicon carbide, crumb rubber, and molybdenum disulfide. Six casting process variables such as SiC, crumb rubber, MoS2, stirring speed, stirring time, and pouring temperature have opted for the fabrication of green hybrid composites via Taguchi L18 mixed-level orthogonal array. Tribological studies (in terms of wear loss, frictional force, and coefficient of friction) on fabricated green composites are examined via the high-temperature rotary pin-on-disc tribometer with fixed process parameters (such as wear track diameter, sliding speed, normal load, sliding distance, disc rotation speed, and test duration) under dry sliding wear test. Moreover, the wear test is also executed under variable temperature conditions of 35 °C, 100 °C, 200 °C, and 300 °C. The metallography of synthesized green composites and their worn surfaces is inspected via a metallurgical microscope and scanning electron microscopy–energy dispersive X-ray spectroscopy techniques. Besides, the analysis of variance is implemented to predict the percentage contribution of the combined process variables for wear loss analysis. In contrast to the as-cast specimen (S0), the developed hybrid pin specimen (S3) yields a tremendous improvement in its metallurgical and tribological attributes under varying temperature conditions. Owing to the merits of the proposed composite, it can be extensively used in lightweight, high-temperature, and wear-resistant applications of various automotive and aerospace engineering.

Machinability Studies of Aluminium-based Hybrid Metal Matrix Composites – A Critical Review

Aluminium composites are being used in many industries like automobiles, aeronautical, signage, cabinetry, cladding and transportation. Aluminium has a lightweight, long lasting, weather resistance, fire resistance and ratio of strength- to- weight is high properties. In today's rapidly developing manufacturing industries, there are many challenges to use metal composites. Also, there is a need to do research on various input parameters, safety parameters and environmental impacts. now, today's era vehicle manufacturing companies are growing up faster. vehicle manufacturing companies are focusing on increasing speed and reducing weight of vehicles so it will be achieved by choosing appropriate metal compositions. For the machining process, a turning operation has been selected. As the material hardness increases cutting forces increase and there is a need to select proper material to cut these composites. For preparing various metal composites stir casting, sand casting, squeeze casting, in-setu method and powder metallurgy process were used. The aim of this study is to give better suggestions and understanding of which material composites should be used? What is the alternative metal by considering operating conditions for machining and performance parameters? Present study is being investigated considering cutting speed, feed rate and depth of the cut while machining and how it affects performance parameters such as high tool wear, hardness, strength, SR, castability and chips production etc. Suggested carbon fibre is an alternative and how it affects the motion of an object and how it adds value in safety by considering certain parameters.

Structural and Mechanical Behavior of Copper-TiC-Graphite Hybrid Metal Matrix Composites Fabricated by Microwave Sintering Technique

For electrical sliding contact applications, there are important criteria such as superior tribological qualities in addition to strong electrical conductivity. This calls for the development of advanced metal matrix composites based on copper. Although adding graphite to a copper matrix results in a self-lubricating feature, the composite’s strength declines. Harder ceramic particles like SiC, TiC, and Al2O3 may be used to reinforce the composite to increase its strength. This study looked at the construction of a hybrid composite made of a copper metal matrix reinforced with TiC and graphite particles. The impact of TiC (5, 10, and 15 vol.%) and graphite (5 and 10 vol.%) reinforcements on the structural, physical and mechanical characteristics of copper-TiC-graphite hybrid composites that were microwave-sintered are thoroughly explored. The consistent distribution of reinforcements in the copper matrix is seen in micrographs. In comparison to traditionally sintered composites, microwave-sintered ones showed greater relative density, sintered density, and hardness.