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The present investigation deals with development of AA2219 composites with different weight fractions of Cerium oxide (CeO2) reinforcement and characterizing the microstructure and mechanical properties thereof. XRD and SEM micrograph confirm the presence of CeO2 particles and Al2Cu precipitate. The grain size of 0, 0.5, 1.0, 1.5 and 2 wt% CeO2 composites are 483, 453, 411, 362 and 328 μm, respectively. Addition of CeO2 significantly reduces the dendritic morphology and refines the α-Al grain structure. 2 wt% CeO2 addition has yielded the maximum hardness of 124 HV and yield strength of 87 MPa in all the composites developed. Additionally, the developed composites were evaluated by examining the wear characteristics with the co-efficient of friction (COF) and the specific wear rate. In this study, Taguchi's L25 orthogonal array was used to optimize the parameters like reinforcement fraction, load and sliding distance. Signal-to-noise ratio (S/N ratio) and analysis of variance (ANOVA) are used to obtain the parameters highly influencing the wear behaviour. Adhesive wear is exhibited by ploughing at lower loads and delamination is observed with increasing load. Deep shallow ploughs with embarked abrasion are observed at higher loads.

The commercially pure magnesium (Mg) was successfully processed through equal channel angular pressing (ECAP) at a set of warm temperature and back pressure up to four passes in different routes. The microstructural, mechanical and wear behavior has been investigated with respect to the number of passes and the processing route. The samples have displayed substantial grain refinement, improved mechanical properties and wear resistance after the ECAP process. The fractographs of tensile samples confirmed fracture mode as a ductile–brittle mixed fracture. The X-ray line profile analysis demonstrates that modifications in the microstructure after ECAP contribute to the improved mechanical properties. The sample processed in route BC exhibits improved mechanical and wear properties owing to its refined microstructure and maximum microhardness.

This work is to optimize the back pressure (BP) and processing temperature required for equal channel angular pressing (ECAP) of commercially pure magnesium. ECAP was performed at different processing temperatures with different back pressures for one pass. For a combination of back pressure and processing temperature the crack-free samples were obtained. Microstructural characterization of pure magnesium samples after ECAP was performed using an optical microscope and mechanical behavior is discussed with hardness and tensile test results. From the XRD peak profiles, the microstructural feature such as crystallite size, micro-strain and dislocation density are analyzed using the modified Williamson and Hall (W-H) method. The results concluded that the processing temperature of 200 °C and back pressure of 150 MPa is the best combination of processing parameters to process crack-free pure magnesium by ECAP.

In-spite of many advantages of Al-Si alloys, it is limited in industrial application due to lack of ductility, because microstructure contains plate like Si particles which is embedded in an Al-matrix. This article describes the modification effect on microstructure and mechanical properties of sodium modified hypoeutectic Al-Si alloys. Modification has been done by using pure Na as modifier with different composition 0.08, 0.12 and 0.16 wt% at 10, 15 and 20 min holding time on hypoeutectic Al-Si alloy. Microstructure of modified samples has been analyzed by optical microscope and eutectic particle size was measured by using ImageJ software. In all cases the modified microstructure has shown the fine fibrous eutectic particle which is uniformly distributed throughout the sample. Tensile and hardness test were carried out by tensometer and Vickers hardness testing machine and the properties were studied. The fracture surface analysis was carried out by SEM. Due to modification, eutectic particle size has reduced and mechanical properties have improved.

The effect of weave pattern on the mechanical properties of basalt- reinforced epoxy composite was investigated. Basalt in the plain and twill weave fabric forms were used for reinforcement, and lapox (L-12) epoxy resin was used as the matrix. Different weave types and their effect on mechanical properties of the weave were considered in the present study. The composite laminate was fabricated by the compression molding technique. Mechanical tests including tensile, compressive, and hardness tests were conducted as per the ASTM standards. Plain weave composites exhibited better mechanical properties compared with twill weave composites. From the results, it was evident that the weave pattern of the fabric significantly influences the strength of fibre reinforced composites.

This study aims at studying the dynamic mechanical and thermogravimetric properties of boron carbide (B4C) filled carbon fiber (CF)/epoxy composites (BC-CF/Ep composites) using the wet lay-up process assisted by vacuum bagging technique. The B4C fillers were used in varying filler weight percentages (1%, 3% and 5%) in the different CF/Ep composites and are uniformly mixed in epoxy system through ultrasonification process and was used as the matrix. The Toray make bidirectional twill (2 × 2) woven T800CF was used as the reinforcing material. The Dynamic Mechanical Analyzer (DMA) and Thermogravimetric Analysis (TGA) tests are conducted to study the dynamic capacity and thermal degradation behavior respectively. In the DMA, the storage modulus (E1), loss modulus (E11), damping behavior (Tanδ) and glass transition temperature (Tg) of CF/Ep composite specimens are studied with increasing temperature from (25–173)°C. The BC1% composites showed better storage modulus, loss modulus and damping factor, while unfilled CF/Ep and BC3% composites showed better Tg than other CF/Ep composites. As far as TGA is concerned, the BC1% composites exhibited better thermal stability than all other composites. The dynamic tests resulted in the trend of BC1% > unfilled CF/Ep > BC3% > BC5% composites. The TGA tests also followed the trend of BC1% > unfilled CF/Ep > BC3% > BC5% CF/Ep composites.

This research focuses on the static mechanical, thermal and tribological properties of carbon fibre epoxy (CF/Ep) composites filled with boron nitride (BN) micro-filler powder (BN-CF/Ep). The mechanical properties studied were tensile, flexural, interlaminar shear strength and hardness. The thermal properties studied were dynamic mechanical and thermogravimetric analyses which were analysed through dynamic mechanical analyser and thermogravimetric analyser, respectively. The curing ability and dispersion of BN filler in the Ep and composites were investigated through differential scanning calorimetry, Fourier-transform infrared spectra and scanning electron microscopy. The tribological properties focused were three-body abrasion and dry sliding friction and wear conduct. Three-body abrasion tests were studied with silica sand of 212 µm particle size, 30 N load, 2.38 m s−1 sliding velocity and variable abrasive distances of 250 m, 500 m, 750 m and 1000 m. The dry sliding wear tests were performed using pin-on-disc (POD) wear experimental set-up with 60 N load, 3 m s−1 sliding velocity and variable sliding distances of 1000 m, 2000 m and 3000 m. The results followed the trend of BN1% > BN3% > BN5% composites in all mechanical properties. The carbon fabric reinforcement along with the BN-Ep matrix improved enormously all the mechanical properties except impact resistance. Further, it was exhibited that 1 wt% BN into CF/Ep prompts better mechanical properties with predominant damping capacity and thermal stability. Both the dry sand abrasive wear and POD test outcomes revealed that all BN-CF/Ep composites prompt predominant wear resistance. CF along with BN improves enormously the wear resistance with friction coefficient. Further, it was exhibited that 1 wt% BN into CF/Ep in both three-body abrasive and POD tests prompts better wear resistance. Generally speaking, it was presumed that BN-CF/Ep gracefully and successfully improved the mechanical, thermal and tribological properties and morphology of Ep for various mechanical, electrical components and load-bearing applications used in automotive and engineered applications.

Cavitation erosion corrosion of AA7075 CNT Hybrid GrP nano Composite is dealt in this paper. Since we know that AA7075 is manufactured for aerospace, automobile industries as a structural material. The need of the hour to strengthen this in manifold. To find the erosion corrosion resistance of such an alloy, was made by compo casting (Stir-Squeeze) are commonly used for the production of components, such as cylinders, pistons, pumps, valves and combustion chambers, which in service may experience a cavitation phenomenon. Microstructure, Hardness, mechanical properties were measured. Cavitation tests were carried out according to ASTM G32 standard and the erosion mechanism was examined by optical microscope and Scanning Electron Microscope. It was found the both CuCNT/CuGrP particles enhances and diminishes cavitation erosion resistance in a particular combination of the two, which is expressed in terms of mass loss, and also galvanic coupling between these particle with matrix behaves differently when it is corrosion. Both the effect are studied simultaneously to see the synergetic effect on different combination of CuCNT/CuGrP particles with AA7075.

The role of metal matrix composites (MMC) has gained huge momentum in the various research as well in the industrial application due to its high stiffness and high strength to weight ratio. It helps in achieving enormous weight reduction without compromise in the strength of the material. In this study, a novel attempt is made to fabricate MMC with martensitic stainless steel as matrix and titanium diboride (TiB2) as reinforcement. The AISI 420 matrix with different weight percentage (0%, 1%, 2%, and 4%) of TiB2 reinforcement was fabricated by vacuum induction melting technique. The fabricated composite was subjected to X-ray diffraction (XRD) study which revealed the presence of TiB2 phase as well as its respective crystal structure. The microstructural characterization of the AISI 420/TiB2 composite was done. Optical microstructure reveals the presence of secondary phase reinforcement in a homogeneous manner inside the matrix and also across the grain boundaries. Scanning electron microscopy (SEM) images further ensure the availability of TiB2 in the matrix. The hexagonal morphology in the SEM ascertains the TiB2 presence. Energy dispersive spectroscopy (EDS) spectrum shows the presence of the T and B elements in the appropriate weight and atomic percentages. Microhardness results of the composite show that the hardness value increases with the more addition in the wt% of TiB2 particles. The overall results confirm that the AISI 420 metal matrix composite with TiB2 reinforcement can be effectively synthesized by casting route. The addition of TiB2 enhances the hardness of the composite significantly

The present article deals with reinforced AA7075 CuCNT/CuGrP Hybrid nano Composite. To find the corrosion resistance of such an alloy composites, was made by compo casting (Stir- Squeeze) are commonly used for the production of components, such as cylinders, pistons, pumps, valves and combustion chambers, which in service may experience a corrosion phenomenon. Initially different percentage of microstructure, hardness, and mechanical properties were measured. Corrosion tests were carried out according to different mass fraction of copper coated CNTs and copper coated GrP was added to the AA7075 casting and the composition is optimised. The electrochemical corrosion behaviour of CuGrP and CuCNT reinforced AA7075 were studied using Electrochemical Polarization Technique (ACM Gill) and Electrochemical Impedance Spectroscopy Technique. The phase analysis of the composites were done by XRD, microstructure by optical microscope even severity of corrosion is measured optical microscope. The corrosion behaviour of the composites and the possible mechanism for the effect of CuCNT and CuGrP in the properties have been studied in detail in this paper.

Rare earth oxide reinforced Aluminium matrix composite are produced using La2O3 as dispersoids in VAL12 aluminium alloy matrix by varying the percentage of dispersoids. The composites are tested for their microstructural evolution and mechanical properties. Advanced characterization techniques are used in characterizing the composites to reveal the microstructural and physical properties. The microscopic examination reveals refinement in grain structure with increasing reinforcement percentage of La2O3. XRD results shows peak broadening of matrix and increase in the intensity of dispersoids peak confirming the presence of reinforcement in the matrix. Energy dispersive spectrum mapping further confirms the elemental composition of the composites. The actual density of the composites are more than 95% of the theoretical density as the squeeze casting process produces with very less porosity level. The tensile test results show loss of ductility in the composites having dispersoids more than 4% (by wt.) which was further elucidated with the fractographic and machining studies. Fractographic results show fracture propagating in both matrix and reinforcement as there is good interface between matrix and reinforcement. The machining studies on developed composites reveal continuous, semi continuous and disintegrated chips, revealing increase in brittle nature with respect to increase in dispersoids percentage.

The influence of crystalline nature of aluminium in mechanical properties of carbon Nanotubes (CNT) reinforced Aluminium alloy is reported. The materials chosen for this study is AA 4032 alloy powders and multi-walled Carbon Nanotubes (MWNT). Three different composites were prepared by powder metallurgy technique. First is an AA4032/MWNT microcrystalline composite, second one is AA4032/MWNT nano-crystalline composites and third one is AA4032/MWNT bimodal composites. The microcrystalline structure was prepared by regular P/M route where nano-crystalline and bimodal structure was prepared by mechanical alloying. The micro-hardness and compressive strength of different composites were measure and analyzed.

The conventional copper alloys with regular grain structure and size are relatively low yield soft materials. To overcome this limitations of conventional tin bronze monolithic material to achieve good combination of strength, along with stiffness, toughness and density, current work focuses on the development of composites using boron carbide particulates as reinforcement. Boron carbide was chosen as a particle reinforcement for composite material for its high hardness, high melting point, low density, with high elastic modulus (448 GPa) and chemical properties. The composites are tested for its mechanical properties and correlated with the microstructural morphological changes using advanced microscopic techniques. The tensile test results shows on increasing percentage of reinforcement, the ductility of the composites is lost. The composites show, microstructural refinement and formation of intermetallic phases, at the grain boundaries justifying increases in the hardness and tensile strength of the as cast composite.

Rare earth oxide reinforced Aluminium matrix composite are produced using La2O3 as dispersoids in VAL12 aluminium alloy matrix by varying the percentage of dispersoids. The composites are tested for their microstructural evolution and mechanical properties. Advanced characterization techniques are used in characterizing the composites to reveal the microstructural and physical properties. The microscopic examination reveals refinement in grain structure with increasing reinforcement percentage of La2O3. XRD results shows peak broadening of matrix and increase in the intensity of dispersoids peak confirming the presence of reinforcement in the matrix. Energy dispersive spectrum mapping further confirms the elemental composition of the composites. The actual density of the composites are more than 95% of the theoretical density as the squeeze casting process produces with very less porosity level. The tensile test results show loss of ductility in the composites having dispersoids more than 4% (by wt.) which was further elucidated with the fractographic and machining studies. Fractographic results show fracture propagating in both matrix and reinforcement as there is good interface between matrix and reinforcement. The machining studies on developed composites reveal continuous, semi continuous and disintegrated chips, revealing increase in brittle nature with respect to increase in dispersoids percentage

An investigation has been performed on the slurry erosion behavior of squeeze cast AA7150 aluminium alloy – a potential structural alloy in as cast condition. The tests were conducted at room temperature varying the service factors using quarts silica sand. The cast samples were examined for its metallurgical and mechanical factors followed by investigation on erosive wear behavior. The results showed the ductile nature of mechanism undergone and greater influence was seen with respect to the angle of impingement. The erodent flow rate also significantly affects the performance of the material. The surface morphologies of the wear tested specimens were examined using SEM for better understanding on the mechanism of failure. Severe plastic deformation is seen in all the cases as the strain energy exceeded the elastic strain rate.

The main aim of this study was to get a better knowledge of mechanical properties of carbon fabric reinforced epoxy (CF/Ep) composites. The selected mechanical properties of the CF/Ep composite with different fiber architectures (T300CF/Ep, T700CF/Ep and T800CF/Ep) are investigated for indentation, in-plane, tensile and bending loads. All composites were fabricated with equal weight percentage of carbon fiber and similar consolidation process using hand layup procedure followed by compression moulding method. Experimental results showed that the effect of fiber weave structure on mechanical properties of the CF/Ep composites is more obvious than that in neat epoxy. Both tensile and flexural results showed that high strength carbon fiber (T800) has evident strengthening effects on the tensile and bending load response of CF/Ep composites. The fiber architecture marginally affects the density and severely affects strength and deformation of composites. T300CF/Ep and T800CF/Ep composites are nearly linear up to final brittle fracture while T700CF/Ep system exhibit non-linearity before failure. Furthermore, it is seen that composite performance is dictated by inherent properties of carbon fiber and weaves structure. Even with fiber flaws, stress concentrations, the weaving pattern is beneficial because it makes composites to be very less subtle to flaws. These characteristics are addressed systematically with consideration of numerical aspects of fibers strength and critical defects formation. The significant developments in the mechanical properties of composite systems are further assisted using scanning electron microscopy

The basic property of corten steel is its ability to create a protective layer on its surface in unfavorable environments. This protective layer protects the steel without an anti-corrosion coating. But owing to water accumulation in passenger coaches near lavatory areas and different climatic conditions especially in high chloride conditions, the protective layer formation is not possible leading to premature failure due to accelerated corrosion. In this work, the corrosion resistance of polyurea coatings compared with present coating was studied on corten steel. The coated steel is subjected to immersion and salt spray test and the corrosion rate are evaluated based on ASTM B117 Standards. The corrosion resistance of coating was assessed by monitoring the polarization resistance of the coated steel immersed in 3.5% wt of NaCl solution. The profilometry of the samples were also done to elucidate the enhancement of corrosion resistance of coated steel.

This research work based on carbon fiber epoxy (CF/Ep) composites shows the effect of Boron carbide B4C filler on mechanical properties using a hand layup procedure followed by the vacuum bagging process method. The boron carbide fillers were uniformly dispersed in epoxy resin and used as matrix material. The weight percentage of (B4C) filler material in the composite was varied and mechanical properties were obtained with microfiller. The T800CF/Ep composites with 1%wt., 3%wt. and 5%wt. B4C fillers were taken for evaluating the mechanical properties. All composites were fabricated with an equal weight percentage of carbon fiber and a similar consolidation process. The mechanical properties like tensile properties, flexural properties, Interlaminar shear strength, impact strength and hardness are studied to know how the mechanical response of composite structures varies with filler addition. Testing followed the trend of 1%wt. > 3%wt. > 5%wt. of B4C in all mechanical properties of B4C filled CF/Ep composites. Tensile strength of 1%wt. B4C filled composites were better than basic CF/Ep composites whereas 3%wt. & 5%wt. B4C filled composite values were lower. The tensile modulus of all the B4C filled composites was better than basic CF/Ep composites. Flexural properties of 1%wt. and 3%wt. B4C filled composites were better than basic CF/Ep composites whereas 5%wt. B4C filled composite values were lower. Interlaminar shear strength (ILSS) of 1%wt. B4C composites gave better results whereas 3%wt. and 5%wt. B4C filled composites gave lower results. The impact energy of all composites gave lower values than basic CF/Ep composites. Hardness values of all B4C filled composites were better than basic CF/Ep composites. The most important developments in the mechanical properties of composites are further supported by scanning electron microscopy.

Air receivers in railway coaches usually come under severe degradation due to exposure to external atmosphere and corresponding climatic changes. IS 2062 Steel is used for this application. Frequent cleaning and replacement become part of the process. Polymer based coating can save this material from corrosion and subsequent wear. In this work poly urea coating was carried out on an IS 2062 steel. The corrosion properties of the coating were studied using potentiodynamic polarization test in ASTM standard 3.5%NaCl solution. The corrosion resistance of coated material was compared with the base material. The depth of corrosion of the samples were studied to evaluate the enhancement of corrosion resistance of coated IS206. The poly urea coating enhances codal life of these material by manifold.

This research paper based on bidirectional carbon fiber/epoxy composites (CF/Ep) shows the effect of fiber architecture on mechanical properties using a hand layup procedure followed by the vacuum bagging process method. The three different fiber architectures T800CF/Ep, T700CF/Ep and T300CF/Ep were chosen for studying the mechanical properties. All composites were fabricated with an equal weight percentage of carbon fiber and a similar consolidation process. The tensile properties, flexural properties, interlaminar shear strength, impact strength and hardness are studied to know how the mechanical response of composite varies with fiber architecture. Testing results showed that the effect of fiber weave architecture is more obvious in CF/Ep composites than in neat epoxy with regard to mechanical properties. Both tensile and flexural properties showed that T800CF/Ep composites have a very good strengthening effect on both tensile load response and bending load response of CF/Ep composites. The fiber architecture has less effect on the density and serious effect on the strength and deformation of CF/Ep composites. Inherent properties and weaves structure of carbon fiber (CF) dictated the performance of composites. Compared to Hand layup method, the Vacuum bagging method showed (2–6)%, (11–15)%, (5–6)%, (15–20)% and (1–3)% improvement in tensile strength, tensile/flexural modulus, ILSS, impact strength and hardness respectively whereas the flexural strength values were almost near to the former values Grunenfelder et al. (2017). The most important developments in the mechanical properties are further assisted by scanning electron microscopy.

The effect of ZrO2(2, 4, 6 and 8 wt%) dispersoids with 1 wt% graphite on the microstructural, mechanical properties on squeeze cast VAL12 matrix hybrid composite is investigated in the present study. The hybrid composites were characterized using advanced characterization techniques to reveal its microstructural and physical properties. The microscopic examinations using optical and SEM technique reveal that the addition of dispersoids accelerates the nucleation kinetics, thus attaining fine, equiaxial grains in hybrid composites. The squeeze cast composites show almost nil porosity, defects and owing to it, the actual density of the composites are found to be more than 95% as that of the theoretical density values. The hardness values and tensile values increase with respect to the increase in percentage addition of ZrO2. The tensile results show that there is an appreciable increase in the UTS values of composites without much loss in its ductility as the addition of graphite improves the self-lubricating property and provides wettability during the casting. Fractographic studies on tensile tested specimen reveal that the crack occurs in both matrix and particles showing the good interface between matrix and dispersoids. Machinability studies reveal the formation of continuous chips in hybrid composites with a lower percentage of reinforcement (up to 4% ZrO2+ 1%Gr) and segmented chips in case of the composite with 8% ZrO2+ 1%Gr, as the increase in the percentage of dispersoids improve the chip breakability of the composites. On an overall, the hybrid aluminium matrix composites with 1%Gr and 6 % ZrO2unveiled better optimal results.

Nickel-based superalloys are used widely in the critical areas of applications such as aerospace, marine, power and many process industries. In this study, solid particle erosion behavior of cast nickel-based CY5SnBiM was analyzed at room temperature. The velocity and angle of the study were set to 59 m/s, 92 m/s and 124.137 m/s, and 30°, 45°, 60° and 90°, respectively; this resembles the exact industrial valve applications. Macrographs were taken to identify the wear scar of material at different angles and different velocities. X-ray diffraction (XRD) was carried out on the material to observe the nature of precipitates. Scanning electron microscopy (SEM) was carried out to identify the plowing action on the material by the erodent in the case of lower angle due to ductile nature of the material. In the case of higher angle, it develops deep pits and craters due to rebounding of erodent particles.

Aluminium composite with VAL12 as matrix and La2O3 as dispersoids fabricated through liquid metallurgy route involving liquid forging operation through squeeze casting process in the present investigation. The frictional characteristics of as-cast aluminium composites are studied under dry sliding wear tests by varying the service factors. The samples prepared were examined for its uniform distribution of the reinforcement, phases formed using advanced characterization facilities. Taguchi orthogonal array method is employed in designing the experiments, and the responses are recorded in terms of wear rate and frictional coefficient. The mechanistic studies are carried out by analyzing the wear surface morphology using SEM. Predominantly AMMC shows delamination and abrasion at higher loads due to thermal softening and adhesive mechanisms at lower loads. Load and sliding distance majorly characterize the wear behavior of the AMMCs under un-lubricated sliding conditions.

This research focuses on the tensile properties, dynamic-mechanical and thermogravimetric analysis of carbon fibre-reinforced epoxy (CF/Ep) composites with graphene nanoplatelets (GnP) nanofiller (G-CF/Ep). These composites were portrayed regarding tensile properties, surface morphology, dynamic-mechanical and thermogravimetric analysis. The dynamic-mechanical properties studied were storage modulus, loss modulus, dynamic capacity and glass transition temperature (Tg) through the dynamic-mechanical analyser. The thermogravimetric property studied was weight loss% through the thermogravimetric analyser. The carbon fabric reinforcement along with the GnP-Epoxy matrix improved the tensile properties. Further, it was exhibited that 1.75 wt% GnP into CF/Ep prompts predominant damping capacity and thermal stability. Generally speaking, it was presumed that GnP-filled CF/Ep composites even with very small wt% GnP gracefully and successfully improved tensile, dynamic-mechanical and thermogravimetric properties as well as the morphology of epoxy for various engineered applications.

Carbon nanotubes (CNT) are synthesized using arc discharge method in an open air. Various amounts of carbon nanotubes-reinforced AA7075 composites are prepared by powder metallurgy route and then hot extrusion at 450 °C. Hot-extruded composites are characterized, and mechanical properties are measured. Dry sliding wear properties of hot-extruded samples were evaluated using a pin-on-disk method for various loads (5-20 N) at room temperature and for various temperatures (100-400 °C) at the applied load 10 N as a function of CNT amount. Grain size of the composites is decreased compared with Al alloy matrix. Transmission electron microscopy of the composites revealed that the CNT are uniformly distributed in the composites. Mechanical properties of the hot-extruded composites are enhanced with an increase in CNT content. The wear performance is improved with an increased CNT amount, but decreases with an increase in the applied load and temperature as well. The wear damage is mild at lower applied loads and temperatures, whereas the damage is severe at 400 °C. The wear mechanism was plowing in the initial stages which is transformed to severe sliding and chipping with increasing load and temperature. The enhanced wear behavior of composites is attributed to self-lubricating nature of carbon nanotubes.

In this work multi-component equiatomic and non-equiatomic AlCoCrCuFeTix hexanary high-entropy alloys (HEA) was synthesised through mechanical alloying. The prepared powder was sintered via spark p...

In this research, friction stir processing (FSP) was used to produce three different surface composites of AA5083 reinforced with B4C, SiC, and TiC particles. The effects of reinforced particles and three consecutive FSP passes on particle distribution, microstructure, mechanical and wear properties were studied. The microstructure reveals significant grain refinement with a dense distribution of particulates towards the retreating side and advancing side of stir zone, some region at the centre of stir zone shows particle free bands and excellent bonding between particle and matrix. FSP induces severe plastic deformation promoting mixing and refining the constituent phase in the materials. Mechanical properties and wear resistance of the FSPed samples were evaluated and compared with the matrix alloy. The results show that the incorporation of B4C, SiC and TiC particles into the matrix improves the hardness, tensile and wear properties. TiC and SiC particulates reinforced surface composites reveals a ductile mode of fracture whereas B4C reinforced surface composite shows a bimodal type of fracture. The investigation on wear mechanism was performed using a pin-on-disc tribometer. The results show that the wear mode changes from abrasive to delamination wear.

The bimodal structured composites of aluminum – carbon nanotubes prepared using powder metallurgy technique with coarse grained AA 4032 powders and nanocrystalline structured AA 4032 powders. Microstructural observations by optical microscope and transmission microscope ensure the complete densification and uniform distribution of carbon nanotubes. These bimodal composites exhibited high compressive yield strength with good ductility. The result shows improved mechanical properties of composites than alloy.

This research emphasizes the impact of Cerium oxide on grain size and corrosion behavior of AA2219 fabricated by the Squeeze casting technique. The composites were effectively characterized by electron backscatter diffraction EBSD, which indicates a significant reduction in grain size inherited by the thermo-physical properties of the dispersoids, which in turn enhances the mechanical properties. The Corrosion behavior of squeeze cast samples was examined through the potentiodynamic polarization technique with Tafel polarization using a standard solution of 3.5% NaCl. The microscopic characterization of the corroded regions reveals that the sample with higher reinforcement of 2% CeO2 is more resistant to the pitting attack due to the hydrophobic nature of the dispersoids.

This research article presents the role of halloysite nanotubes (HNTs) incorporated carbon fabric/epoxy under a dry sand three-body abrasive wear (D3BW) condition. HNTs filled carbon fabric/epoxy nanocomposites are structured by hand layup assisted by the vacuum bagging process. The experiments were planned using L16 Taguchi array. The load, abrading distance, and filler loading were considered as a controlling factor. Wear volume loss associated in D3BW with two different sand particles size (212 μm and 425 μm) were investigated. Post-wear surface morphology was observed under the scanning electron microscope, and micro-cutting, and micro-ploughing were predominant. Both 212 μm and 425 μm sand particles had a similar wear volume loss, but, the composites were wear-resistant towards the 425 μm sand particles. Based on the experimental results, analysis of variance and multi-linear regression models, the load, abrading distance, load + abrading and load + filler loading had considerable impact on the abrasive wear on the composites. However, the filler loading had no definite impact on the abrasive wear behaviour.

The current research work focused on the abrasive wear behavior of the basalt fabric as reinforcement in epoxy and polyester composites. Traditional hand-layup technique is used to manufacture the composites. The mechanical characteristics of the basalt fiber reinforced composites have been reported. The two body abrasive wear behavior of the fabricated composites was conducted by using pin/ball on disc tester TR-20 disc equipment. Test were conducted at two different load of 5 N and 10 N, for various sliding distances of 25 m to 100 m at equal intervals with 400 grade grit of particle size 35 μm. Wear resistance of the composites were determined by calculated the specific wear rate of the composites. Basalt fiber as reinforcement in epoxy composites showed better wear resistance than basalt fiber as reinforcement in polyester composites. Wear mechanism of worn samples is conducted by using the Scanning Electron Microscopy (SEM).

Surface properties decide the fatigue, wear and corrosion behavior of a material. Hence their performance can be improved by surface modifications. Friction Stir Processing (FSP) is a promising technique to develop surface composite. The aim of the present study is to develop defect free surface composite of Al 5083 alloy reinforced with TiC particles and investigate the particle distribution in the matrix, mechanical properties and wear behavior of the composites. Microstructural observations were carried out by using optical and scanning electron microscopy (SEM). The microstructural studies revealed that distribution of particles were more uniform in samples subjected to double pass than the single pass FSP. The microhardness profiles along top surface and across the cross section of the processed samples were evaluated. The average hardness along the top surface was found to increase by 27.27%, as compared to that of the base metal (88Hv). The particles were incorporated maximum average depth about 250μm in the surface composite. The slurry erosion tests revealed that the wear rate was highly reduced in case of double pass FSP samples as compared to base metal and single pass FSPed composite

Carbon nanotubes (CNTs) reinforced aluminum matrix composites were fabricated using powder metallurgy technique. The effect of nanotubes content on mechanical properties of the composites was investigated. Experimental results showed that nanotubes are homogeneously distributed in the composites. The corrosion of AA 4032 alloy based nanocomposite with CNTs was investigated by electrochemical polarization studies. CNTs-reinforced composites have shown a better corrosion resistance than parent alloy. The nanotubes content significantly affect mechanical and corrosion properties of composite.

Three-body abrasive wear behavior of basalt–epoxy (B–E) and glass–epoxy (G–E) composites have been investigated using Dry sand rubber wheel abrasion resistance for various abrading distance, viz., 150, 300, 450 and 600m and different loads(22N and 32N) at 200 rpm. The weight loss and specific wear rate as a function of load and abrading distance were determined. The weight loss increases with increasing load and also with abrading distance while the specific wear rate decreases with increase in abrading distance and increases with the load. Better abrasion wear resistance was observed in B-E composite compared to G–E composite. Scanning Electron Microscope (SEM) is used to examine the abraded composite specimens and revealed that the more damage occur to glass fiber compared to basalt fiber. Also good interfacial adhesion was observed between epoxy and basalt fiber which leads to good abrasive wear resistance.

In the present work, Al–TiC composites were synthesized by Flux Assisted Synthesis (FAS) route. In this in situ method the TiC particles are generated from the reaction between the mixture of K2TiF6 salt and graphite in the molten aluminium. The XRD peaks have confirmed the presence of the TiC and no other undesirable intermetallics have formed after reaction. After casting the composites were extruded and then aged. All the cast, extruded and aged composites samples have exhibited significant improvement in mechanical properties in comparison with the monolithic alloy. The erosion corrosion test have been performed and found that wear resistance of the composites have significantly improved by the presence of TiC particles. Optical and Scanning electron microscopy were used for microstructural analysis and XRD was used for phase analysis. Mechanical testes were performed as per the ASTM standards.

In this work, multi-walled carbon nanotubes (MWNTs) were successfully reinforced in AA 4032 nanocrystalline matrix. The elemental powders of AA 4032 composites were mechanically alloyed in the high energy ball mill for 30 h to get nanocrystalline structure. The carbon nanotubes (CNTs) were added at the 29th hour of ball milling process. The morphological changes during milling were studied, using scanning electron microscope analysis and the distribution of the CNTs within the aluminum matrix was successfully revealed, using transmission electron microscope analysis. The results show that the CNTs are effectively distributed within the aluminum matrix without any structural damage. The variation in the melting point was studied using simultaneous thermal analyzer.

Effect of filler material on sliding wear behavior of Glass-Epoxy (G-E) composites has been investigated. The sliding distance, applied load, sliding velocity and temperature are the parameters used for the study. The fabricated wear specimens were tested by using pin-on-disk test rig. The result shows that the wear loss increases with increase in temperature and applied load and under the same conditions the coefficient of friction decreases. However, graphite-filled G-E composite exhibits lower wear rate and lower coefficient of friction as compared to unfilled composite. The features of worn surfaces of the specimens were examined under scanning electron microscope.

Nanocrystalline AA 4032 alloy powder was synthesized by high-energy ball milling from elemental powders for 30 h duration. XRD and TEM results reveal that the powder is cubic and nanocrystalline in nature. X-ray peak broadening analysis was used to evaluate the lattice strain and the crystallite size using the WilliamsonHall analysis with three different models viz., uniform deformation, uniform deformation stress and uniform deformation energy density. The root mean square (RMS) strain was calculated from the interplanar spacing and the strain estimated from the three models. The three models yield different strain values due to the anisotropic nature of the material. The energy density model is proposed to be the best fit model among the three as severe lattice strain is associated with ball milled powders. � 2010 Elsevier B.V. All rights reserved.

The effect of ultrahigh molecular weight polyethylene (UHMWPE) on solid particle erosion behaviour of aramid fabric reinforced-epoxy (A-E) hybrid composites was investigated. The aramid fabric reinforced-epoxy hybrid composites have been fabricated with and with out UHMWPE filler. The solid particle erosive wear was evaluated at different impingement angles from 300 to 90 0 at constant velocity and at constant standoff distance .The silica sand of size 30 -50 and 60 -80 μm was used as erodent. The results show erosive rate of UHMWPE filled aramid- epoxy composite shows lowest value. The presence of UHMWPE in epoxy matrix gives good bonding between filler and matrix. The morphologies of eroded surface were examined by the SEM in order to establish the erosion mechanism of the composites.

The effect of tungsten carbide (WC) particulate fillers incorporation on two-body abrasive wear behaviour of glass fabric reinforced-epoxy (GE) composites was investigated and findings are interpreted. The wear behaviour of the composites were performed using pin-on-disc tester at varying abrasive distances viz., 25,50,75 and 100 m at a constant load of 20 N. The experiment was conducted using two different water proof silicon carbide (SiC) abrasive papers and at two different velocity under multi-pass condition. The wear loss of the composites found increasing with increase in abrading distances. A significant reduction in wear loss and specific wear rates were noticed after incorporation of WC filler into GE composite. This result indicates a significant improvement in wear resistance after incorporation of WC filler. The WC loaded systems exhibit less wear of matrix during abrasion which in turn facilitates lower fiber damage, due to the presence of WC particles on the counter surface which act as a transfer layer and effective barrier to prevent large-scale fragmentation. The worn out surface features were examined through scanning electron microscopy (SEM) in order to probe the wear mechanism.

An investigation was made to evaluate the effect of the incorporation of jatropha oil cake (JOC) alone and in combination with silicon carbide (SiC) on the mechanical and tribological wear behaviour of glass fabric–epoxy (GE) composites. A vacuum-assisted resin transfer moulding (VARTM) technique was employed to obtain a series of GE composites containing different fillers viz., silicon carbide, jatropha oil cake and a mixture of SiC and JOC. The effect of different loads (22 and 32 N) and abrading distances from 135 to 540 m on the performance of the wear resistance of the composites were measured. The mechanical properties such as tensile behaviour and hardness of the composites were evaluated. A linear relationship was found between the wear volume loss and the abrading distances. The JOC filled GE composite exhibited a lower specific wear rate by 6 and 10% at 540 m abrading distance for a load of 22 and 32 N, respectively, as compared to that of unfilled GE composites. The worn surface features of unfilled and filled GE composites were examined using scanning electron microscopy (SEM).

In the present work, AA 6351-xZrB2 [x = 0, 3, 6 and 9 weight percentage (wt.%)] in situ composites have been prepared by the reaction of mixture of K2ZrF6 and KBF4 with molten aluminium alloy at a reaction temperature of 850 °C. The in situ prepared composites were characterized by using scanning electron microscope (SEM), X-ray diffractometer (XRD), and microhardness analysis. The sliding wear properties of the prepared composite at room temperature were estimated by a pin-on-disc wear testing equipment using the composite material; the pins were machined according to standard sizes, and the tests were conducted as per the standards recommended by the ASTM G99-95a designation of different weighing percentage at room temperature. The wear characteristics of the composite in the as-cast, the solutionized and the solutionized-aged conditions were studied by conducting sliding wear test at the load of 9.81 N. The results indicated that the wear rate was decreased with an increase in the weight percentage of ZrB2 and the wear resistance was increased with an increase in the fraction of ZrB2 particulates in composite before and after heat treatment.

Powder metallurgy has emerged as a promising technique to develop carbon nanotubes reinforced metal matrix composites. In this work, high energy ball mill was used to disperse multi-walled carbon nanotubes in AA 4032 alloy. The nanocrystalline nature of AA 4032 was obtained by milling the elemental powders for 30 hours. Different mass fractions of carbon nanotubes were added in the matrix at end of 29th hour. The phase evolution and changes in crystallite size and lattice strain were analyzed using X- ray diffractometer (XRD). SEM analysis reveals the morphological changes during the milling process. Transmission electron microscopy (TEM) studies reveal the presence of CNTs in the matrix and evidenced the uniform distribution of CNTs inside the matrix.

This technical paper covers statistical analysis of the major tribological factors affecting the dry sliding wear behaviour of Al–SiC p –brake pad system. The composite material for investigation was developed by conventional liquid casting route from Al 6082 alloy by incorporating 15% SiC p by weight. The Design of Experiments was done based on response surface method. The factors selected for investigation were temperature, load and sliding velocity keeping sliding distance constant. Experiments were conducted on high-temperature pin-on-disc wear testing equipment. Commercially available brake pads were used as the pin material. Response selected for analysis was wear rate of the AMC disc. Hardness survey, Optical microscopy and SEM were used to characterise the materials before and after the wear tests. Worn surfaces and debris were characterised using SEM to understand the wear mechanisms. ANOVA results show that temperature is the most dominant factor affecting the wear rate.

A low cost system of Al 6063 − x TiB 2 ( x = 0, 5, 10 wt.%) in situ metal matrix composites (MMCs) were prepared by the reaction mixture of K 2 TiF 6 and KBF 4 with molten alloy. These in situ prepared composites were characterized by using scanning electron microscope, X-ray diffractometer, and microhardness analysis. The dry sliding wear behaviour of the prepared composite was investigated by using a Pin on Disc method at different applied loads of 9.8, 19.6 and 29.4 N for various temperatures (100, 200 and 300 °C). The study at room temperature was also carried out for comparison purpose. The results indicate that the wear rate decreases with the increase in the weight percentage of TiB 2 , while it increases with the increase in the applied load.

In the present experimental investigation, Al 6063–xTiB2 [x = 0, 5, and10 weight percentage (wt.%)] in situ composites have been prepared by the reaction of mixture of K2TiF6 and KBF4 with molten Al alloy at a reaction temperature of 850 °C. The wear characteristics of the composite in the as-cast conditions were studied by conducting abrasive wear test, and slurry erosive test. The abrasive wear behaviour of the metal matrix composites (MMCs) were investigated by varying parameters like wt.% of TiB2 particles and load. Dry Sand Rubber Wheel Abrasive Wear (as per ASTM G65 standard) testing machine was used for investigating abrasive wear behaviour. It is evident from the experiments, that in situ formed TiB2 particles offer effective coverage to the matrix and restrict the metal removal by abrasive particles. In slurry erosion, wt.% of TiB2, distance traversed and time was used as variables. The results indicate that the wear resistance of TiB2-reinforced material increased with increase in TiB2 content. The overall results reveal that TiB2 particles markedly improve the wear performance of Al 6063 alloy. The surface morphologies of the worn out surfaces were analyzed using SEM. In case of abrasive studies, the mechanism appears to be a mix-up of micro-cutting, ploughing and grain pull-out, while for erosion it is found mainly due to plastic deformation and voids.

In the present work, multiwalled carbon nanotubes (MWNTs) were synthesized by electric arc discharge method in open air atmosphere. The synthesized nanotubes were subjected to multistep purification followed by characterization using Raman spectroscopy and transmission electron microscopy (TEM). These carbon nanotubes (CNTs) have inner and outer diameters of the order of 3.5 nm and 16 nm with an aspect ratio of 63. AA 4032 nanocomposites reinforced with MWNTs were produced by high energy ball milling using elemental powder mixtures. X-ray diffraction (XRD) and scanning electron microscope (SEM) studies showed different phases of composite with and without CNTs. The crystallite size and lattice strain were calculated using an anisotropic model of Williamson–Hall peak broadening analysis, which showed in decreased crystallite size with increasing milling time. TEM studies reveal that the MWNTs were uniformly distributed in the matrix. Thermal stability of the nanocrystalline powders was studied using a differential thermal analyzer (DTA). The mechanically alloyed powders were consolidated using a novel method called equal channel angular pressing (ECAP) at room temperature. The consolidated samples were sintered at 480 °C in argon atmosphere for 90 min. ECAP method was investigated as an alternative to conventionally sintered powder composites. CNT addition has shown significant improvement in the hardness of the system, even though the observed density is relatively low compared with a base alloy. Thus, the results show that ECAP enables sufficient shear deformation results in good metallurgical bonds between particles at lower compaction pressures. Hence, it is proven that ECAP can be effectively used as one of the consolidation technique especially for powders that are difficult to consolidate by other means.

The present paper emphasizes the friction and wear properties of Carbon Nanotubes reinforced AA 4032 nanocomposites prepared by powder metallurgy technique. CNTs are multi-wall in nature and prepared by electric arc discharge method. Multi-walled CNTs are blended with AA 4032 elemental powders and compaction followed by sintering to get bulk nanocomposites. The strength of the composites has been evaluated by microhardness and the surface contact between the nanocomposites and EN 32 steel has been evaluated by Pin on disk tester. The results are proven that reinforcement of CNTs play a major role in the enhancement of hardness and wear.

Pump casings made of grey cast iron (GCI) used in lignite mines for dewatering are subjected to erosive wear and fail catastrophically. An attempt was made to modify the surface of GCI by WC–Co–Cr/NiCrBSi coating using HVOF process for the application under mining conditions. Grey cast iron samples with and without WC–Co–Cr/NiCrBSi coating were subjected to slurry jet erosion tests by varying the impingent velocity and angle under two different pH conditions of 3 and 7 which pertain to the mining environment. XRD characterization was done to identify and confirm phase composition. Eroded surface morphology studies were carried by SEM on both the substrate and coating, which revealed the erosion of GCI surface, predominantly due to ploughing mechanism. In the case of WC–Co–Cr and NiCrBSi coating, at an oblique angle of impact, the material removal from the surface is by micro cutting of the matrix, ploughing, and abrasive mode mechanisms. At normal impingement, the fluctuating stress creates the cracks, which interlink each other to form lips and craters followed by material degradation through fatigue. Performance of WC–Co–Cr coating is found to be better than NiCrBSi Coating.