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Performance characteristics of SS410 stainless steel during the drilling process while conducting experimental studies is discussed in this paper. The material was blocked up from the ingot form and has the following dimensions of 100x75x15 mm. Drilling experiments were carried out on BMV 35 T12 Gaurav BFW CNC machine using HSS drill bit. Process parameters such as Speed (S) (30, 40, 50, 60 m/min), Feed (F) (0.05, 0.075, 0.1, 0.125 mm/rev) and Point angle (P) (100, 110, 120, 130 degree) were varied for about four levels, to determine the test cases with the help of Taguchi’s Orthogonal Array. The methods used for analysing the results were; response table, Signal to Noise ratio and Analysis of Variance. It was concluded that better surface finish was obtained at high spindle speed, low feed, and high point angle, better material removal rate was obtained at high spindle speed, high feed, and low point angle and better dimensional accuracy (ovality) was obtained at low speed, low feed, and low point angle. Analysis of Variance (ANOVA) results revealed feed as the most significant parameter that influenced the surface roughness (Ra) of SS410 material, followed by speed and point angle. Similarly, for material removal rate (MRR) and ovality (O), speed was the most influencing parameter followed by feed and point angle. To predict the Ra, MRR and O, regression analysis was also performed and was validated through confirmation test.

This paper reports novel eco-friendly reduction of GO to RGO (BRGO) by Musa paradisiaca extract for choice in many areas of application. However, the layer by layer tight stackin in their thin film form inevitably diminishes the interlayer space between homogeneous ultrathin nanosheets, which could significantly hinder the electrolyte diffusion. Herein, Fe3O4 nano particles are uniformly dispersed on MWCNT with the less agglomeration and then fabricated composite with BRGO for energy storage (supercapacitor) and water remediation (photocatalytic) application. After preparation, the BRGO Fe3O4-MWCNT nanocomposite was characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), UV–Visible spectroscopy (UV), transmission electron Microscopy (TEM) and scanning electron microscope (SEM) analyses. The electrochemical behaviour of the material was analysed by cyclic voltammetry (CV), galvanometric charge–discharge (GCD) study and impedance spectroscopy. The photocatalytic degradation was carried out in a photocatalytic chamber. The synthesized nanocomposite exhibited a high specific capacitance value of 165 F/g at 2 A/g and also showed good photo degradation efficiency on the methylene green dye (MG), which is higher than the degradation efficiency of other individual materials like Fe3O4-MWCNT and BRGO. The prepared nanocomposite was found to have good cyclic stability in the capacitance study and it mineralizes the organic dye to an extent of 94%. BRGO-Fe3O4-MWCNT as effective nanocomposite for application as advanced supercapacitor electrode and developing novel photocatalyst for remedy of environmental problems.

This research compares the reciprocating tribo-mechanical behaviour of functionally graded A333 (Al-9Si-3Cu) alloy, Al-9Si-3Cu/6wt%B4C mono-composite and Al-9Si-3Cu/6wt%B4C/4wt%TiB2 hybrid-composite. Cylindrical test samples of both alloy and composites were horizontal centrifuge cast. Metallography of alloy revealed grain refinement and throughout presence of B4C particles along the cross-section of both functionally graded composites. Whereas, a rising gradient of TiB2 particles were observed towards the outer zone of hybrid composite. Comparative analysis on micro-hardness and tensile strength, revealed an improvement of 37.4% and 17.6% respectively for outer hybrid-composite; 22.6%, and 12.2% respectively for outer mono-composite with respect to alloy. Reciprocating wear analysis confirmed superior anti-wearing at outer hybrid-composite. Worn morphological analysis confirmed predominant delamination wear mechanism for outer zones of alloy, mono and hybrid composites. Abrasive, adhesive and delamination wear in combination, led to oxide layer formation at intermediate sliding distances. Hybrid composite is functionally graded and developed for automotive engine component applications.

Recently, cylinder liners of automotive and aircraft engines are encountered severe wear due to piston slap occurred by the repeated sliding stroke of piston. This research focuses on providing an alternative material for cylinder liners, which can be obtained through friction stir processing on AA7075 with different weight ratios of reinforcements like Al2O3 and SiC. Friction stir processing is executed with a tool rotational speed of 1000 r/min and traveling speed of 56 mm/min at 2° tool tilt angle. The images of optical microscopy reveal the fine-grains with a homogeneous distribution of secondary phase particles and also offer decrement in particle clustering except at some localized regions. It is identified that addition of 3.7 wt.% Al2O3 + 3.0 wt.% SiC in AA7075 enhanced the microhardness about 33.96% higher than base matrix. Hence, wear resistance of the specimen is improved. Dry sliding wear behavior of specimens is analyzed using pin on disc at 20, 40, and 60 N load conditions to create the actual sliding behavior of piston on cylinder wall. Increasing the wt.% of Al2O3 particles enhanced the wear resistance of AA7075 surface hybrid composites at 20 N load due to the formation of protective tribofilm. Specimen with 3.7% Al2O3 + 3.0% SiC has better lubrication and load-bearing capacity that exhibits superior tribological behavior at 40 and 60 N. Higher Fe content of 5.44 wt.% has been obtained through spectroscopy analysis in S5, which is 8% and 6% higher than S3 (7.5% of Al2O3) and S7 (6% of SiC), respectively. The scratching action of this hard specimen on the counterpart brings more Fe content. Increase of Al2O3 particles paved the way for tribofilm formation and identified through scanning electron microscopy micrographs. The observation from worn specimens shows that finer wear debris had increased by adding more quantity of SiC particles due to abrasive wear mechanism.

This study investigates the effect of Strontium (Sr) grain modifier addition on Al-9Si alloy and B4C reinforced composite fabricated by two step gravity casting technique. The optimum level of Sr was identified as 0.08 wt.% for complete modification. The modified cast components were thermally treated by T6 temper to enhance the tribo-mechanical properties. Metallographic observation revealed the transformation of acicular Si grains to fine fibrous in as-cast condition, which later transformed to spheroidised eutectic Si after heat treatment. The combined effect of grain modification by Sr and the influence of spheroidised eutectic Si enhanced the mechanical properties. Heat treated modified composite exhibited superior tribological properties when compared to other components under varying applied normal loads and sliding distances. Worn mechanism of heat treated modified composite was observed to be minor delamination wear regime at high load (55 N) and sliding distance (1500 m).

LM25 aluminum alloy reinforced with 10 wt% of TiB2, WC, and ZrO2 were squeeze cast to investigate the effect of T6 heat treatment on tribo-mechanical properties. Among all, WC-reinforced composite achieved superior mechanical properties at the aging time of 8 h. Microstructural examination performed on all composites and alloy concluded that the presence of WC in T6 LM25 caused reduction of α-Al dendrite size, exhibiting superior properties for this composite. X-ray diffraction analysis conducted on alloy and WC-reinforced superior composite revealed formations of phases, which improved their mechanical properties. Energy-dispersive X-ray spectroscopy analysis quantified the actual intensity of WC presence in the superior composite along with its other constituents. Response surface methodology model developed for wear test of the superior composite involves parametric range like applied load (10–50 N), sliding velocity (1–4 m/s), and sliding distance (500–2500 m). Analysis of variance along with regression analysis proved that, statistical analytical model developed good relationship between the actual wear rate and process parameters. Response surface plots represented the linearly increasing wear trend with respect to load and sliding distance. Wear rate dropped initially and raised later on along with velocity. Scanning electron microscopy exhibited the surface deformation prevailing on the composite surface at high load.

This study investigates the tribo-mechanical behaviour of as-cast and heat treated A359/ 6 wt.% Ti-based particulate reinforced homogeneous composites (TiB2, TiO2, and TiC) processed through modified stir casting technique. Metallographical observation on as-cast homogeneous composites revealed a uniform distribution of reinforcements throughout the cross-section. In heat treated composites, the tribo-mechanical properties were enhanced by the formation of spheroidized alpha eutectic Si. TiB2 and TiO2 exhibited superior interfacial bonding with Al-matrix, whereas TiC showed marginal wetting. Linear reciprocating wear experiments were performed on all as-cast and heat treated components by varying loads (15–55 N) and sliding distances (500–2500 m). Results revealed superior hardness (182.5 HV), tensile strength (271.6 MPa) and wear resistance for heat treated A359/TiB2 composite than TiO2 and TiC reinforced composites. The wear rate and coefficient of friction was observed to be dependent on the applied load and type of reinforcement particle in the composites. Worn surfaces of composites exhibited severe delamination wear mechanism.

Cu-10Sn-4Si reinforced with 10 wt. % SiC was synthesized using stir casting technique and cylindrical specimens of diameter 20 mm and length 150 mm were obtained.Dry sliding wear behavior of copper composite was analyzed by performing experiments using pin-on-disc tribometer. Taguchi’s method was utilized for designing the number of experiments using L16orthogonal arrayfor investigating the wear behavior. Three factors and four level design was selected namely Load (15N,25N,35N,45N), Velocity (1.5m/s,2.5m/s,3.5m/s,4.5m/s) and Distance (500m,1000m,1500m,2000m).Optimization of parameters was done using the Signal-to-Noise ratio. Analysis of Variance results revealed that load had the most impact on wear rate followed by sliding velocity and distance. The regression equation was developed and validated with confirmation experiment. X-ray diffraction analysis was conducted on the worn specimen to find out phase formations. Scanning Electron Microscopy analysis were performed on the surface of worn specimens and found that more delamination occurred at a load of 45 N

CuNiSi/Si3N4 is fabricated by using the stir casting method. Metal matrix composite developed is tested to study the adhesive wear behaviour on wear and friction apparatus under dry sliding state using Taguchi’s L27 orthogonal array. The process parameters were load (15,25,35N), sliding velocity (1,2,3m/s) and sliding distance (750,1250,1750m). In light of the outcomes, load applied is the most influencing variable on the wear loss abided by sliding distance and velocity. Scanning electron microscope analysis exposed serious delamination of specimen under high load and sliding distance. The developed copper composite can replace aluminium bearings, cylinder liners, radiators, connecters.

The current study focuses on improving the mechanical and reciprocating wear characteristics of centrifugally cast functionally graded A356(Al-7Si-0.3 Mg)/10 wt.% B4C composite through T6 heat-treatment. Comparative analysis was performed between as-cast and heat-treated composite. Metallographic analysis confirmed the presence of reinforcement particles alongside grain boundaries and spheroidised eutectic silicon particles in heat-treated composite. Outer layer of heat-treated composite displayed superior hardness (24.09%), ultimate tensile strength (44.8%) and tribological properties when compared to outer layer of as-cast composite. With increasing applied load (15, 25, 35 N), wear rate and co-efficient of friction increased whereas wear rate and co-efficient of friction decreased as sliding distance (500, 1000, 1500 m) increased. Worn morphologies confirmed extreme delamination wear and particle pull-out at high applied loads whereas traces of oxide formations were observed at high sliding distance. Heat-treated composites have superior characteristics due to the presence of spheroidised eutectic silicon particles and precipitate formation, which makes it an alternative material for reciprocating applications in aerospace and automotive industry.

Non lubricated slide performance of functional grade copper matrix composite, fabricated using horizontal centrifuge cast technique was investigated using pin-on-disc tribo-tester. Rate of wear and friction coefficient of the inner wall thickness of hollow cylindrical cast specimen was analyzed using Taguchi based L27 orthogonal array, where the percentage of graphite particles were observed higher. Variable process parameters those influenced the rate of wear directly or indirectly were: applied load (15, 25 and 35 N), slide velocity (1.5, 2.5 and 3.5 m/s) and slide distance (750, 1500 and 2250 m). Rate of wear and friction coefficient showed a proportional dependency with applied load and slide distance, whereas showing a decline during intermediate slide velocity. Signal-to-Noise ratio predicted the minimal tribo-condition, on ‘smaller-the-better’ basis. Analysis of Variance technique quantified the influence of affecting parameters, along with their interactions. Regression analysis was utilized for the validation of the experimental data. Micrographs and scanning electron microscopy exhibited the wear mechanisms and mechanically mixed layer formation during worn surfaces analysis.

Functional grade composites Cu–10Sn–5Ni reinforced with 10 wt%SiC and 10 wt%Al2O3, respectively, and their alloy was developed through horizontal centrifuge cast technique. Sample composites and alloy were cast at cylindrical dimensions of Φout100 × Φin70 × 100 mm. They were later subjected to tribology analysis during non-lubricated sliding. Anti-wear performance variations at inner (0–8 mm) and outer (8–15 mm) wall thicknesses of both composites and alloy were experimented using pin-on-disc tribo-tester. Experimentation with increasingly varied parameters like load and slid distance showed a rising trend of wear and friction. This was observed while comparing between the least (10 N, 500 m) and highest (60 N, 3000 m) varied parameter; for both alloy and composites. Also, a proportional decline in coefficient of friction with increase in slid velocity was exhibited for both composites; whereas alloy showed a linear rise. Worn specimen analysis using scanning electron microscopy on both composites revealed Mechanically Mixed Layer formation at both zones. This caused reduction in friction coefficient at high velocity (6 m/s). Keywords: Centrifuge casting, Functional graded materials, Adhesive wear, Scanning electron microscopy

Aluminum/titanium diboride (TiB2) in-situ metal matrix composite was produced by reaction between aluminum alloy and potassium hexafluoro titanate (K2TiF6) and potassium tetrafluoro borate ...

The current study aims to synthesize copper alloy and functionally graded Cu-10Sn-5Ni/10Si3N4 composite using horizontal centrifugal casting method and compare their mechanical and adhesive wear characteristics. The fabricated castings have dimensions of Oout100 x Oin70 × 100 mm. Microstructural analysis revealed that inner region of composite possesses higher concentration of reinforcement particles, resulting in better hardness and tensile properties at this region compared to outer regions of both unreinforced alloy and composite. Analysis of dry sliding wear performance and frictional coefficient was performed at inner region of the composite under different sliding conditions using Taguchi’s method on pin-on-disc tribometer. Signal-to-Noise ratio and Analysis of Variance results concluded that applied load had the most influence on wear rate and coefficient of friction followed by sliding distance and sliding velocity. Worn surface morphologies of composite specimens revealed a transition from mild to severe wear at high loads. The fabricated composites are well suitable for sliding tribological applications.

The key objective of the paper is to investigate the mechanical and wear Properties of functionally graded copper composite (Cu–11Ni–4Si) reinforced with 10 wt% graphite synthesised using stir casting followed by horizontal centrifugal casting technique. Microstructural analysis conducted radially from outer surface exhibited an increasing gradient of particle distribution and maximum hardness of 195 HV was observed at inner surface. Tensile strength of outer and (1–8 mm) and inner zone (9–15 mm) was determined and failure mechanism was analysed. Mechanical tests revealed better properties at inner surface and wear resistance of this layer was analysed using pin-on-disc tribometer based on Taguchi’s L27 orthogonal array with three process parameters, applied loads (10, 20 and 30 N), sliding velocities (1, 2 and 3 m s−1) and sliding distances (500, 1000 and 1500 m). Optimum parameters were identified and confirmation of experiments was carried out. Worn surface was analysed using Scanning Electron Micrograph and oxide layer formation was noticed at increased velocities which enhanced wear resistance.

The functionally graded Cu-11Ni-4Si/10wt%WC composite and its alloy have been synthesized using horizontal centrifugal casting technique to compare the mechanical and tribological improvement and its utility for bearings and bushes. Microstructure analysis and mechanical tests showed 43% improvement in hardness and 160% improvement in tensile strength at inner radial distances compared to the outer composite periphery. Fractural analysis showed ductility for alloy, whereas for composites, brittleness at outer and a combination of both ductility and brittleness were observed at inner. Proportional rise in the wear rate and coefficient of friction was observed with increasing load and sliding distances for both composite and alloy. Composite showed a slight decline in the wear rate and coefficient of friction with an increase in the sliding velocity, while alloy showed a linear rise. Worn surfaces analysis of composite showed the formation of oxide layers, which reduced the coefficient of friction at higher sliding velocity, resulting in lower wear rate.

Cu-11Ni-4Si/10wt.% Si3N4 functionally graded composite of dimension Oout 100 mm × Oin 70 mm × 100 mm was fabricated via centrifugal casting and the mechanical and three body abrasive wear behavior were studied. Microstructural analysis along the radial direction revealed high concentration of Si3N4 particles at the inner periphery of the composite, and XRD analysis confirmed the presence of introduced reinforcement. Highest micro-hardness (207 HV) was observed at the inner periphery of composite having highest concentration (53 vol.%) of reinforcement particles and the inner zone displayed higher tensile strength (425.58 MPa). Abrasive wear test based on L27 orthogonal array, was performed only at inner periphery based on the mechanical behavior. Signal-to-Noise ratio and Analysis of Variance were performed to analyze the influence of parameters such as load, speed and time on wear rate. Results showed that applied load had the highest influence (60.45%) on wear rate followed by speed and time. Scanning electron microscopy analysis was carried out on worn samples and was observed that wear changed from mild to severe as parameters were increased. This composite is suited for automotive applications where the improved abrasive wear characteristics can be utilized to a greater effect.

Aluminium 6063 alloy as substrate was coated with WC-12% Co using the detonation spray gun technique. The coated specimen showed 5.6x increase in hardness over the uncoated substrate. Wear analysis...

The preparation of semiconductor Quantum Dots (QDs) with controllable size, shape and doping remains a biggest challenge, especially the size below 10 nm. To date, only scarce attempts have been made on the synthesis of ZnSe QDs using biomolecule-assisted hydrothermal approach. Hence the current research work examines the influence of some amino acids namely L-cysteine, methionine and tyrosine as stabilizing agents in the synthesis of ZnSe nanocrystals. The ZnSe QDs exhibited strong absorption and photoluminescence properties in the region from 200-600 nm. Spectroscopic and structural properties of the as-synthesized biomolecule-capped ZnSe QDs were characterized by UV-vis absorption spectrophotometer, FT-IR, fluorescence spectrophotometer, X-ray diffractometer, Scanning Electron Microscope and EDX analysis. The stabilizing agents have played a crucial role in preparing ZnSe QDs and in determining the photoluminescence properties. The luminescence intensity was enhanced significantly when amino-acid-capped ZnSe QDs were illuminated by UV light compared to visible light. The as-synthesised ZnSe QDs were capable of effectively degrading an organic azo dye Azophlexin, under direct sunlight irradiation and exhibited good stability during photocatalytic experiments which can be attributed to the small size of amino acid capped ZnSe. The degradation mechanism is discussed. The absorbance and FT-IR measurements confirmed the biocompatibility and water-solubility of the pure ZnSe and capped ZnSe QDs.

LM13/12wt.%Si3N43wt.%Gr hybrid composite was fabricated by liquid metallurgy route and its tribological characteristics were tested using pin-on-disc tribometer. The experiments were conducted as per L27 orthogonal array to study the influence of process parameter at normal and elevated temperature (150 °C) by varying process parameters such as load (10, 20, 30 N), sliding velocity (1, 2, 3 m/s) and sliding distance (750, 1250, 1750 m). The results revealed that the wear rate at both temperatures was proportional to load due to the stress induced which fractures Si3N4 particles and stripes aluminium matrix. As the sliding velocity increases, wear rate showed an increasing trend due to three body abrasion from eroded Si3N4 grits. The wear rate was inversely proportional to sliding distance, because of MML (Mechanically mixed layer) formed from chemical reactions between tribo-layers. When load increases COF (Coefficient of friction) decreases then increases due to lubricating and tillage effect. As velocity and distance increases, COF decreases due to thermal softening, hardening of layer and also the lubrication effect produced by chemical reactions. Analysis of variance (ANOVA) and S/N ratio at room temperature and elevated temperature for both Wear rate and COF were developed to study the most significant parameters on corresponding responses. Confirmation experiments were conducted to validate multi-linear regression model. Worn surfaces were examined using scanning electron microscope (SEM) to investigate wear characteristics. Energy dispersive X-ray spectroscopy (EDAX) and X-ray diffraction (XRD) results confirmed the formation of MML and different phases formed during wear mechanism. The developed material can be used to fabricate cylinder liners, cylinder blocks and brake rotors.

Al 6060 alloy was coated with TiO2 by spray pyrolysis technique at 400 °C using Titanium isopropoxide as precursor. The adhesion of the coating with the alloy was enhanced by annealing at 450 °C for 1 h which increased the hardness by 50%. Dry sliding wear resistance was experimented based on Taguchi’s L27 array using pin-on-disc tribometer by varying parameters such as applied load (15, 25 and 35 N), sliding distance (500, 1000 and 1500 m) and sliding velocity (1.5, 2.5 and 3.5 m/s). Analysis of Variance predicted the major influence by load, followed by velocity and distance. Trend depicted an increase in wear rate with load and distance, whereas with velocity it decreased initially and then increased. Optimum condition for maximum wear resistance was determined from the Signal-to-Noise ratio. Experimental results were validated using regression equation with an error less than 3%. Scanning Electron Microscope analysis of the worn surfaces had revealed more defoilage and lay-off as the applied load was increased.

The objective is to fabricate Cu-10Sn alloy and its composites reinforced with varying wt% of SiC (5, 10 and 15) to investigate its dry sliding wear behaviour. Microstructural analysis for composites revealed well dispersed SiC particles within matrix except for 15 wt% SiC composite, where agglomeration took place. Amongst all composites and alloy, 10 wt% of SiC composite had better hardness (144 HV). The tribological analysis using Pin-on-Disc tribometer for all alloy and composites revealed increase in wear rate with increase in load and distance for all combinations of parameters (load, sliding distance, and sliding velocity). Worn surface analysis concluded that the wear rate decreased with increase in velocity for both 5 and 10 wt% SiC composite due to formation of Mechanically Mixed Layer. The composite with 10 wt% SiC showed enhanced wear resistance and hence can be used for tribological applications like bearings and bushes.

This paper aims to study the dry sliding wear characteristics of LM13 aluminum alloy matrix containing titanium disulfide (TiS2) as the reinforcement (10 wt%, average size 37 µm) fabricated...

This paper involves the fabrication of LM13/TiO2 (12 wt%)/MoS2 (3 wt%) hybrid metal matrix composite and unreinforced alloy using liquid metallurgy route and evaluation of mechanical properties and...

The objective of this research is to fabricate a functionally graded Cu/SiC composite (Oout100 × Oin85 × 100 mm) using a horizontal centrifugal casting technique and to examine its mechanical and dry sliding wear characteristics. Microstructure of the composite was observed at outer (1 mm), middle (8 mm) and inner (14 mm) regions using a metallurgical microscope and results showed that the inner region had a high concentration (35%) of reinforcement particles compared to the other two regions. Mechanical properties were tested along the radial direction of the composite and results showed that maximum tensile strength and hardness were found to be 341 MPa and 280 HV respectively, at the inner region of the composite. Fractograpy examination revealed that the outer and inner regions were fractured by ductile and brittle modes of failures, respectively. The dry sliding wear tests were performed only at the inner region of the composite with selected parameters of load (10–30 N), sliding distance (500–1500 m) and sliding velocity (1–3 m/s) using a pin-on-disc tribometer. Analysis of variance and signal-to-noise ratio were used to study the effects of parameters on the wear rate of the composite and it was found that the load (54%) had highest influence followed by sliding distance (18.2%) and sliding velocity (3.7%). Worn surfaces were observed by a scanning electron microscope and it was confirmed that mild wear, severe plastic deformation, ploughing, delamination and wear debris were important wear mechanisms at different sliding conditions. Hence, this composite is suggested for use in bearings and bushes application, where the wear resistance is a primary consideration.

This study investigates the mechanical and tribological properties of a functionally graded Cu–Sn–Ni/Al2O3 metal matrix composite, synthesized using horizontal centrifugal casting technique...

Functionally graded metal matrix composite (Cu-10Sn/10 wt% SiC) was successfully fabricated by horizontal centrifugal casting method. The cast specimen of O100 x 100 x 20 mm was obtained. The centrifugal die rotates at 900 rpm and particle rich zone is obtained at inner periphery of cast sample due to the density difference between matrix and reinforcement. The specimen of dimension 75 x 25 x 12.5 mm was cut from the cast and abrasive wear test was carried out only at inner surface as per Taguchi’s Design of Experiment technique. L16 Orthogonal array was selected and experiments were carried out using three body dry abrasion tester by varying the process parameters such as load (25, 45, 64,89N), time (3, 5, 7, 9 mins) and speed (50,100,150,200 rpm) for four levels. Silica sand AFS 50/70 was used as an abrasive medium. The influence of these wear process parameters was analysed using Minitab software. Taguchi design provides analysis of experiments using Signal-to-Noise ratio and Analysis of Variance to find out the optimum level of parameters as well as its influence of each parameter on the response. The results revealed that, wear rate increases with increase in applied load and decreases and then increases as speed and time increases. Time was observed to be the most dominating factor (38.1%) followed by load (27.6%) and speed (22.8%). The worn surfaces were analyzed at varying parametric condition using Scanning Electron Microscope and found severe delamination with plouging as the major mechanism at high load condition.

Requisite for advanced materials with high hardness, high tensile strength and improved wear properties has been drastically increased in recent times. The main objective of this paper is to fabricate unreinforced copper alloy and Cu-Sn/SiC composite with varying wt% of SiC (5, 10, and 15) by liquid metallurgy route and to investigate its microstructure, mechanical properties and dry sliding wear behavior. The hardness and tensile strength of alloy and composites are measured on Vickers micro hardness tester and Universal Testing Machine respectively. Tensile test specimens are further subjected to fractography analysis and the results shows ductile mode of failure for alloy and mixed ductile and brittle mode failure for composites. Based on the test results, it is observed that Cu-Sn/10 wt% of SiC have uniform distribution of particles with optimum mechanical properties. Hence only these 10 wt% SiC composite is considered for dry sliding wear analysis and experiments are conducted using Pin-on-disc tribometer. Analysis of process parameters in three levels such as applied load (15,25,35 N), sliding distance (750,1250,1750 m) and sliding velocity (1,2 and 3 m/s) is done by Taguchi’s Design of Experiments technique based on L₂₇ orthogonal array. From Signal-to-Noise ratio and Analysis of Variance approach, the rank of process parameters as well as its influence on the response is found. The results reveal that the wear rate increases as applied load and sliding distance increases and the wear rate decreases as sliding velocity increases. The load is found to have the highest influence on wear rate (38.5%) followed by sliding distance (7%) and sliding velocity (7%). Interaction between the process parameters also contributed towards wear rate. The worn surfaces were examined using Scanning Electron Microscopy and observed the formation of mechanically mixed layer at high velocity condition. Thus, the fabricated composites can be used in applications like bearings and bushes to improve the wear resistance.

The objective of this work is to fabricate functionally graded unreinforced copper alloy (Cu–10Sn) and a Cu–10Sn/SiC composite (Oout100 × Oin70 × 100 mm) by horizontal centrifugal casting process and to investigate its mechanical and tribological properties. The microstructure and hardness was analysed along the radial direction of the castings; tensile test was conducted at both inner and outer zones. Microstructural evaluation of composite indicated that the reinforcement particles formed a gradient structure across the radial direction and maximum reinforcement concentration was found at the inner periphery. Hence maximum hardness (205 HV) was observed at this surface. Tensile test results showed that, the tensile strength at inner zone of composite was observed to be higher (248 MPa) compared to that of the outer zone and unreinforced alloy. As mechanical properties showed better results at inner periphery, dry sliding wear experiments were carried out on the inner periphery of composite using pin-on-disc tribometer. Process parameters such as load (10–30 N), sliding distance (500–1500 m) and sliding velocity (1–3 m/s) were analyzed by Taguchi L27 orthogonal array. The influence of parameters on wear rate was analyzed by signal-to-noise ratio and analysis of variance. Analysis results revealed that load (54%) had the highest effect on wear rate followed by sliding distance (18.2%) and sliding velocity (3.7%). The wear rate of composite increased with load and sliding distance, but decreased with sliding velocity. Regression equation was developed and was validated by confirmatory experiment. Worn surface of composite was observed using scanning electron microscopy and transition of wear was observed at all extreme conditions.

This paper studies the dry sliding wear behavior of Al–Si6Cu/Ni coated SiC metal matrix composite fabricated using stir casting technique. The SiC reinforcement particles coated with Ni by electroless coating were incorporated at 10-wt% into the metal matrix. The wear behavior was studied on unlubricated pin-on-disc tribometer based on design of experiments modelled using Response Surface Methodology for various sliding parameters such as applied load, sliding velocity and sliding distance. The minimum wear rate condition and optimum condition of the parameters were detected from the developed model. The analysis of variance showed the influence of each parameter on wear rate. The confirmation experiments were done to ensure the validity of the developed regression model. The worn-out surface morphologies of the metal composite were studied using scanning electron microscope analysis. From the experimental results it was found that the parameter which influenced the wear behavior was applied load followed by sliding velocity and distance. The confirmatory experiments confirmed the RSM’s design as precise statistical model in developing regression results with less error. The surface plot of wear characteristics showed that irrespective of the conditions of sliding velocity and distance the wear rate increased on increasing the load. The wear rate exhibited a non linear relationship with sliding velocity and distance. The scanning electron microscopy revealed that higher material deformation was observed at higher load resulting in severe wear of the composite material.

Centrifugal casting was adopted for fabricating AlSi5Cu3/10 wt% SiC functionally graded metal matrix composite under three different centrifugal speeds of 800, 1000 and 1200 rpm, and hollow cylindrical components (φout 150 × φin 132 × 150 mm) were obtained. Microstructures of outer and inner periphery of all composites were observed through optical microscope and micro hardness of outer, intermediate and inner region of composite was tested using Vicker’s hardness tester. Results revealed that outer region of the composites centrifuged at all speeds have particle rich region with higher hardness. Abrasive wear experiments were conducted only on surface of particle rich region based on Taguchi’s technique by varying parameters such as centrifugal speed of casting process, rotating speed and applied load of abrasive wear tester. Analysis of variance results revealed that, centrifugal speed had highest significance on wear rate. Abraded surfaces were examined using scanning electron microscope and the maximum wear resistance was observed on particle rich zone of composite centrifuged at 1200 rpm.

Several engineering components require location specific performance under operating conditions. A compositional/microstructural gradient can provide the performance required at specific locations and these materials were named as functionally graded materials. Functionally graded aluminiu...

l-Cysteine capped zinc oxide (CCZ) nanoparticles (NPs) were synthesized by the chemical precipitation method. They were immobilized onto a biodegradable poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) [P(3HB-co-3HHx)] by electrospinning. ZnO, CCZ and immobilized CCZ were spectrochemically characterized using X-ray diffraction, photoluminescence and Fourier transform infrared spectra. The surface morphology of the catalyst was studied by scanning electron microscopy technique. The as-synthesized material exhibited excellent photocatalytic activity for the degradation of rhodamine B (RhB) dye under both UV and visible light irradiation. The higher photocatalytic activity of the immobilized CCZ in the degradation of RhB was mostly attributed to their web structure with small size. It was found that the immobilized CCZ retained its photocatalytic activity up to three successive catalytic runs, which was found difficult with bare ZnO. Thus, the P(3HB-co-3HHx) support would be useful in immobilizing metal oxide NPs for diverse applications owing to its biodegradability and biocompatibility.

This paper deals with the study of dry sliding wear of LM25/silicon dioxide (10 wt.%) functionally graded composite. The composite was fabricated using stir casting technique and the melt was poured into a horizontal centrifugal die rotating at 1200 min−1. After casting, the specimen (length 150 mm, external diameter 150 mm and internal diameter 130 mm) was subjected to microstructure and hardness tests at three different depths from the outer periphery (1 mm, 8 mm and 13 mm). The results of the respective tests revealed that the outer periphery of the specimen had higher particle concentration and hardness. Then, wear test was done on a pin-on-disc tribometer at room temperature with the experiments designed using response surface methodology and by taking specimens of size 8 x 8 x 15 mm such that the surface undergoing wear was at 1 mm from the outer periphery of the cast. The process variables of load (10 - 40 N), velocity (1 - 4 m/s) and sliding distance (400 - 1200 m) were varied using a level 5 design and experiments were carried on for 20 different optimal combinations. From the regression equation generated for the wear response, it was found that load had maximum effect on the wear rate. The confirmation experiments proved that the regression model could serve well in predicting the wear rate for the given ranges of the continuous factors, for the given composite. Surface plots showed that the wear rate had an increasing trend with respect to load, which was the dominating continuous factor. Though the wear rate increased, severe delamination of the functionally graded composite was delayed. The optimum levels of the continuous factors to minimize the wear rate were found using response optimisation and found to be 10 N, 1.7576 m/s and 2000 m respectively. Scanning electron microscopy analysis of the worn surface of the specimens connected to the obtained trends and thus further validated the model developed. Thus, a functionally graded LM13 composite with silicon dioxid reinforcements is developed and a wear model to predict its wear rate under different process parameters is proposed with predictions of optimal performance conditions. This composite can increase life of components of wear applications in aerospace and automobile industry.

Functionally graded LM13 Al/10 wt% TiB2 metal matrix composite has successfully produced under centrifugal casting. Hollow cylindrical composite with dimensions 150 × 150 × 15 mm was produced under rotating centrifugal speed of 1100 rpm. Microstructural characteristics were studied on the composite surfaces at distance of 1, 5.5, and 10 mm from outer periphery of the casting, and the results revealed that surface at distance of 1 mm has presence of more reinforcement particles. An objective of this study was to characterize abrasion wear behavior at the composite surfaces using dry abrasion tester. Mathematical models were developed using response surface methodology to study the relationship of parameters such as load, speed, and distance from outer periphery with abrasion wear rate. Face centered Central Composite Design with 20 experiments was preferred for dry abrasion test. Adequacy of model was predicted through analysis of variance, and the significance test result shows that load has major...

In this paper, the abrasive wear behavior of Al LM 25/10 wt% TiC metal matrix composite has been studied experimentally. The composite specimens were fabricated using stir casting technique. Microstructural evaluation revealed uniform distribution of reinforcement particles throughout the matrix. Abrasive wear experiments were designed for different values of load, speed and time through response surface methodology and were performed using three body abrasion tester. Surface plots for wear rate against all combinations of parameters revealed that wear rate increased with increasing load and time, but decreased with increasing speed. The generated regression equation established proper relation between parameters and wear rate, confirming the accuracy of the developed model. The results of optimization of process parameters revealed that a minimum wear rate of 0.00104 mm3/Nm was obtained at 27 N, 139 rpm and 3 min. Scanning electron microscope analysis results substantiated that wear rate was comparatively more at higher loads.

Aluminum LM25/TiC (10 wt%) metal matrix composite was developed using the liquid metallurgy route. The microstructural examination and the mechanical properties such as hardness and tensile strength were investigated on the composite specimens. The tribological behavior of the composite was studied using central composite design (CCD) based on response surface methodology (RSM) under the influence of wear process parameters such as applied load, sliding velocity and sliding distance. Pin-on-disc tribometer was utilized for conducting the experimental runs and the model was constructed based on the obtained wear rates. Confirmation experiments and analysis of variance were performed to ensure the adequacy of the constructed model. Microstructural examination reveals that uniform dispersion was attained in the composite, which enhances the hardness and the tensile strength. The wear results showed that the wear rate increased with increase in load, decreases with increase in velocity and varies nonl...

Homogeneous and functionally graded LM25 aluminium (Al) composites were fabricated by incorporating silicon nitride (10 wt%, 40 µm) particles through liquid metallurgy and centrifugal casting, respectively. The performance of these composites was compared with unreinforced alloy. The microstructural behaviour of the surfaces of unreinforced alloy, homogeneous composite and functionally graded composite (outer, middle and inner surfaces) were examined through optical microscopy. These surfaces were also evaluated for mechanical properties. An abrasive wear test was conducted on all these surfaces to determine their effect on wear rate. The microstructural results revealed a particle-rich region at the outer surface of the functionally graded composite material and uniform dispersion of reinforcement particles in the homogeneous composite. The outer region of the functionally graded composite showed greater hardness and the homogeneous composite displayed higher tensile strength. The abrasive wear rate increased with an increase in load and decreased with an increase in speed, and the particle-rich outer surface showed a lower wear rate. Scanning electron microscopy analysis revealed a particle-rich outer surface of functionally graded composite with fewer scratches. Therefore, higher wear resistance was observed at the outer periphery of functionally graded composites and this property can be well-utilised in automotive tribo-components such as in cylinder liners for improved performance.

Functionally graded metal matrix composites (MMCs) and homogenous composites (Al/AlN and Al/SiO2-10 wt%) have been fabricated through centrifugal casting and liquid metallurgy route, respectively. The properties of these composites were compared with aluminum alloy. Microstructural characteristics and hardness were studied on the surfaces of functionally graded materials (FGMs), homogenous composites, and unreinforced aluminum alloy using an optical microscope and a Vickers micro hardness tester, respectively. Tensile test was carried out on the outer and inner sections of FGMs and specimens from homogenous composites and alloy utilizing universal testing machines (UTMs). Three-body abrasive wear test was conducted for different loads and speeds to study their effect on the surfaces of composites and alloy using dry abrasion tester. Microstructural and hardness results reveal that the outer surface of aluminum nitride (AlN)-reinforced FGM has a particle-enriched region with the highest hardness. T...

Functionally graded aluminum composites reinforced with different average sized (15, 44, and 74 µm) aluminum diboride (AlB2) particles (10 wt%) have been fabricated through centrifugal casting process. The outer, middle, and inner surfaces of all the functionally graded composites were tested for their microhardness using a Vicker's hardness tester. The outer and inner zones of all the composites were investigated for their tensile strength using a universal testing machine. The abrasive wear test was conducted using dry abrasion tester on the outer region of the composites based on Taguchi's design of experiments, under the influence of parameters such as load, speed, and reinforcement size. The analysis of variance was performed and determined that load has major significance on the wear rate followed by reinforcement size and speed. Scanning electron microscopy analysis was performed on the worn-out surfaces and it was observed that outer surface of coarser particle reinforced composite with le...

Mechanical properties and abrasive wear behaviour of functionally graded Al-Si12Cu/Al2O3 metal matrix composite fabricated under centrifugal casting technique was investigated and compared with unreinforced aluminium alloy. Hollow cylindrical component with dimensions 150 × 150 × 16 mm was produced under the centrifuging speed of 1200 rpm by incorporating 10 wt% Al2O3 particles of size 30–50 µm. The distribution of the Al2O3 reinforcement particles at outer, middle and inner surfaces in matrix was examined through the microstructural analysis. Hardness and tensile strength of the aluminium alloy and functionally graded composite were tested through microhardness tester and universal testing machine respectively. Abrasive wear of aluminium alloy and functionally graded composite was tested through dry abrasion tester for various loads and speeds on outer, middle and inner surfaces of composite specimens. Scanning electron microscopy analysis was carried out on the fractured tensile specimens and worn out specimens. The results revealed that particles were segregated more on the outer periphery and less on the inner periphery. The mechanical properties and the abrasive wear resistance of the functionally graded material were found higher than the unreinforced alloy. The wear rate was found to increase with increase in load, speed and for the distance from the outer periphery of the casting. The worn out surfaces revealed more cutting and ploughing as a result of three body abrasion wear caused by silica sand particles.

Functionally graded Al/B4C, Al/SiC, Al/Al2O3 and Al/TiB2 composites with constant 12% (mass fraction) of reinforcement were fabricated by centrifugal casting and hollow cylindrical components were obtained. Microstructural characteristics were investigated at outer surface of all composites and segregation of reinforcement particles was observed. Graded property of the composites with different reinforcements was investigated through hardness and tensile measurements. Results revealed that the outer peripheries of all composites exhibit higher hardness except in Al/B4C composite and the outer zones of all composites show higher tensile strength. Abrasive wear test was conducted on the outer peripheries of all composites and Al/TiB2 composite exhibits less wear rate.

The objective of this research work is to synthesize functionally graded Cu-11Ni-4Si/10 wt % SiC, Cu-11Ni-4Si/10 wt % Si3N4 composite using horizontal centrifugal casting method and to analyze its mechanical and adhesive wear behavior. The cast samples with dimension of Øout100 × Øin70 × 100 mm were synthesized and variation in volume of SiC and Si3N4 particles on inner (1 mm), middle (8 mm), and outer surfaces (15 mm) along radial direction of the composites was analyzed. Microstructural images revealed that inner zone of the both composites had highest distribution of reinforcement particles. Tensile tests on inner (1–7 mm) and outer (8–15 mm) zones of composites revealed that the inner zones had highest tensile and yield strength. Fractography test was conducted for both composites at inner and outer zones to observe the mode of failure. Hardness tests taken along radial direction of the composites revealed that, the inner surface had better hardness and it reduced toward outer periphery. The outer and inner surfaces of Cu/SiC were compared with Cu/Si3N4 composites and results revealed that inner surface of Cu/SiC had highest wear resistance among all surfaces of composites. It was also observed that, while increasing load, wear rate increased with it for all composites. Wear rate of composites majorly decreased while increasing the sliding velocity due to formation of tribolayer. Scanning electron microscopy (SEM) analysis carried out on worn surfaces of Cu/SiC and Cu/Si3N4 composite revealed that, plastic deformation, and plowing were the dominant wear mechanism for varied parameters.

Functionally graded Al LM 25/10 wt% WC composite of dimension ∅out 100 × ∅in 60 × 100 mm was fabricated using centrifugal casting method. Mechanical and tribological properties of outer (1 mm), middle (11 mm) and inner (18 mm) layers from outer periphery of hollow cylindrical component were studied. Microstructural investigation revealed maximum distribution of reinforcements in outer layer, followed by middle and inner layer. Outer periphery had the highest hardness while outer zone displayed better tensile characteristics. Fractographs revealed brittle nature at outer layer due to high concentration of WC particles while a combined mode of ductile and brittle failure was observed at inner layer. Wear rate of outer layer increased linearly with increasing applied load, nonlinearly with increasing sliding velocity and sliding distance. Worn surface morphologies revealed fine and shallow grooves at outer layer ensuring mild material removal. Mild to severe wear transition was observed with increasing applied load. Mechanically mixed layer formation was observed with increasing velocity. This composite having enhanced mechanical and wear properties at outer zone is suitable for automotive applications such as pistons, liners, brake disks and bearings.

A functionally graded Cu–10Sn–5Ni metal matrix composite (MMC) reinforced with 10 wt % of Al2O3 particles was fabricated using the centrifugal casting process with dimension Φout100 × Φin85 × 100 mm. The mechanical and wear resistance of the composite has been enhanced through heat treatment. Samples from of the inner zone (9–15 mm) were considered for heat treatment, as this zone has higher concentration of less dense hard reinforcement particles. The samples were solutionized (620 °C/60 min) and water quenched followed by aging at different temperatures (400, 450, and 550 °C) and time (1–3 h). Optimum parametric combination (450 °C, 3 h) with maximum hardness (269 HV) was considered for further analysis. Dry sliding wear experiments were conducted based on Taguchi's L27 array using parameters such as applied loads (10, 20, and 30 N), sliding distances (500, 1000, and 1500 m), and sliding velocities (1, 2, and 3 m/s). Results revealed that the wear rate increased with load and distance whereas it decreased initially and then increased with velocity. Optimum condition for maximum wear resistance was determined using signal-to-noise (S/N) ratio. Analysis of variance (ANOVA) predicted the major influential parameter as load, followed by velocity and distance. Scanning electron microscope (SEM) analysis of worn surfaces predicted the wear mechanism, observing more delamination due to increase in contact patch when applied load increased. Results infer 8% increase in hardness after heat treatment, making it suitable for load bearing applications.

The modern technology developments have seeded for the necessity of composite materials that are incorporated with high hardness, high tensile strength, and better wear properties. Cu–Sn–Ni alloy as well as the composites of varying weight percentage of Si3N4 (5, 10, and 15) are fabricated by liquid metallurgy technique. The alloy and composites are tested for their tensile strength and hardness on Universal Testing Machine and Vickers microhardness tester, respectively. Based on the tests, Cu–Sn–Ni/10 wt. % of Si3N4 is found to have optimum mechanical properties. The scuff type adhesive wear behavior is studied through pin-on-disk tribometer under dry sliding conditions for Cu–Sn–Ni/10 wt. % of Si3N4 composite. Taguchi's design of experiments technique based on L27 orthogonal array model is used for analyses of process parameters in three levels such as applied load (10, 20, and 30 N), sliding distance (500, 1000, and 1500 m), and sliding velocity (1, 2, and 3 m/s). The parameters are ranked based on the signal-to-noise ratio and the analysis of variance approach. Based on wear results, applied load is found to have highest stature on influencing wear rate followed by sliding distance and sliding velocity. A generalized wear rate equation is obtained based on the linear regression model and its feasibility is checked. Scanning electron microscope (SEM) analyses revealed severe delamination occurred on maximum load condition. The development of this copper composite can have the possibility of replacing aluminum bearings.

LM13/AlN (10 wt. %) metal matrix composites (MMC) and unreinforced aluminum alloy were produced under stir casting route. Microstructural characteristics were examined on the developed composite using optical microscope. The hardness and tensile test were carried out on both unreinforced aluminum alloy and composite using Vickers hardness tester and universal testing machine (UTM), respectively. Dry sliding wear behavior of the composite and unreinforced aluminum alloy was evaluated using pin-on-disk tribometer based on the design of experiments approach. Experimental parameters such as applied load (10, 20, and 30 N), velocity (1, 2, and 3 m/s), and sliding distance (500, 1000, and 1500 m) were varied for three levels. Signal-to-noise (S/N) ratio analysis, analysis of variance, and regression analysis were also performed. The characterization results showed that reinforcement particles were uniformly distributed in the composite. The hardness and tensile test revealed greater improvement of property in composite compared to that of unreinforced alloy. Wear plot showed that wear was increased with increase in load and decreased with increase in velocity and sliding distance. S/N ratio analysis and analysis of variance (ANOVA) indicated that load has greater significance over the wear rate followed by velocity and sliding distance. Regression analysis revealed greater adequacy with the constructed model in predicting the wear behavior of composite and unreinforced aluminum alloy. Scanning electron microscopy (SEM) analysis is evident that the transition of wear from mild to severe occurred on increase of the load in the composite.

LM13/15 wt. % TiS2 metal matrix composite (MMC) was fabricated by stir casting method and its abrasive wear characteristics were tested on the dry abrasion tester. The tribological characteristics of the MMC were analysed using Taguchi's L9 orthogonal array by varying process parameters such as load (26, 31, 36 N), speed (100, 150, 200 rpm) and time (280, 300, 420 s) for three levels. It is inferred from results that wear rate increased as the load increased due to higher contact pressure. When speed is increased, wear also increased because of accumulation of heat on the surface. Whereas when abrading time is increased, the trend is decreasing because of oxide layer formation. Analysis of variance and S/N ratio shows that the load is the most significant parameter on wear rate abide by speed and abrading time. Scanning electron microscope (SEM) was used to study the wear mechanism of worn out surfaces. EDAX and XRD confirm the oxidation of aluminium.

Functionally graded Cu11Ni4Si/10wt%TiC composite is fabricated using centrifugal casting and machined using wire-electrical discharge machine. The research objective is to find the optimal process parameter during machining and to study its influence on material removal rate (MRR) and surface roughness (Ra). The experiments were conducted on L9 orthogonal array by varying process parameters such as pulse on time (TON-115,120,125 µs), peak current (IP-100, 150, 200A) and wire feed rate (WF-2, 3, 4 mm/min). The trend of TON for MRR increased initially and then decreased, whereas for Ra, the trend is increasing. The relationship of IP and MRR initially decreased and then increased, whereas for Ra decreased steadily. The trend for WF was found to be linearly increasing for both MRR and Ra. Analysis of variance and S/N ratio revealed that the WF(98.19%) was the most significant parameter influencing MRR followed by TON and IP. TON(74.63%) was the most significant parameter influencing Ra followed by IP and WF.