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Aluminium hybrid functionally graded metal matrix composites (FGMMCs), meet growing demands for supreme tribo-mechanical performance in automotive and aviation industry. This research experimentally compares the influence of carbide ceramics (B4C, SiC, TiC) as reinforcements, in improving reciprocating tribology performance and mechanical strength of A333 hybrid composites against alloy. Hollow cylindrical samples of A333/6 wt%B4C/4 wt%TiC and A333/6 wt%B4C/4 wt%SiC hybrid FGMMCs were developed using horizontal centrifugal casting. Metallography analysis on both composites revealed increasing ceramic gradient distribution towards outer composite wall. Particle rich zone of A333/B4C/SiC hybrid FGMMC showed maximum micro-hardness (198.9 HV) and tensile strength (267.9 MPa). Elemental mapping confirmed effective distribution of ceramics and detected elemental composition of both composites. Particle rich layer of A333/B4C/SiC hybrid FGMMC exhibited improved wear resistance in comparison with all three layers of A333/B4C/TiC hybrid FGMMC and alloy. Third-body abrasion and tribo-chemical wear were the predominant mechanisms revealed for both composites during worn surface analysis.

The present work discusses an attempt to enhance the mechanical and reciprocal wear response of Al–7Si-0.3 Mg alloy through the addition of 10 wt% SiC as reinforcement and subsequent T6 treatment. Friction and reciprocating wear behavior of both untreated and heat treated functionally graded composites were studied under unlubricated sliding conditions, employing a linear reciprocating pin-on-plate system over a range of applied load (10–50 N) and sliding distance (500–2500 m). Microstructural studies revealed reinforcement particle gradation across the cast thickness for untreated composite with minimal particle clusters whereas, heat treated composite showed the presence of fine α-spheroidised eutectic silicon. The outer layer of heat-treated composite when compared to outer layer of as-cast composite, revealed an 18 % increase in hardness, 70 % increase in tensile strength and 8 % decrease in wear rate. Wear studies confirmed a linear dependency between wear rate and applied load whereas, coefficient of friction displayed fluctuating trends. Wear mechanisms were identified, with worn morphology and EDS analyses in agreement with the results obtained and was correlated with the observed metallurgy and mechanical properties. These composites were identified as potential candidates for applications such as brake drums/rotors, cylinder liners, cylinder blocks and pistons.

Modern technology demands have raised the popularity of aluminum metal matrix composites (AMMCs) as it best suits diverse industrial applications. The need to develop an advanced functional material for specific applications attracts global researchers. Commercial needs for cost-effectiveness, quality improvement, superior performance and high strength to low weight ratio are met by composites. Mass production of AMMCs for specific industrial applications prefer stir casting as a simple and cost-effective manufacturing method. In addition, the production of composites turn more economic by reducing the weight percentage of ceramics and adding natural fibers either in the form of fibers, milled powder or ash to achieve the targeted properties. Process parameters being a dominating factor for minimal defect composites, their effect on final cast products are discussed along with strengthening mechanisms. This paper also discusses the applications, challenges and future scope of natural fiber reinforced AMMCs.

Dry sliding performance of Cu-11Ni-4Si/10wt.%Al2O3 graded composite was investigated statistically and experimentally using pin-on-disc wear tester. Microstructural analysis revealed maximum gradient concentration of ceramics towards the inner radial wall of developed composite. The wear analysis was based on Taguchi’s L27 orthogonal array and Regression models, at tribo-parameters (load-15, 25, 35 N, slide velocity-1.5, 2.5, 3.5 m/s and slide distance-750, 1500, 1250 m). Wear raised with proportional rise in load and distance. Trend analysis of influential factors against wear response was studied using Analysis of Variance. The influence of process conditions and their interactions on the wear are also detailed. Worn surface analysis identified the formation of Mechanically Mixed Layers at intermediate velocity. This had a major influence over the improvement of wear resistance. This developed composite is suggestable for diverse automobile components of various tribology applications.

Functionally graded materials (FGMs) revealed an immense growth with world-wide demand. This paper details a critical review on the periodic transformation in FGM production technologies and influence of thermal treatment on the physical, structural and manufacturing characteristics of FGMs. Popular alloys and ceramics utilized for FGM manufacturing are identified and classified based on their engineering applications of diverse fields. Evolution of fabrication techniques are correlated to the industrial requirements along with their merits and limitations. Advanced research outcomes of studies on FGM gradation control, coating precision, residual stress distribution, energy consumption, commercialization and environmental impacts are compared. Cross-linkage of product demands are correlated within the FGM designs to simulate desired gradation and geometries for specific complex applications. Detailing on impact of integrating advanced FGM development with emerging trends like nano-technology and additive manufacturing, provides an insight for industrialists and academic researchers on current FGM trends and potential future research gaps.

We report in this the development of nanocomposite rutin-reduced graphene oxide/titanium oxide (R-rGO/TiO2) through a chemical precipitation method to enhance the electrochemical detection and photocatalytic efficiency of the 2,4-dichlorophenol (DCP). The structural and morphological characterization of the as-fabricated nanocomposites were carried out by X-ray diffraction, Fourier transforms infrared spectroscopy (FT-IR), scanning electron microscopy, transmission electron microscopy, etc. The R-rGO/TiO2 electrochemical sensor was developed for 2,4-dichlorophenol (DCP) and rutin oxidation based on composite altered glassy carbon electrode (GCE). Moreover, R-rGO/TiO2/GCE composite exhibited accomplished electrocatalytic activity towards DCP in the linear range 5–150 μM and a low detection limit of 0.02 μM (S/N = 3). The TiO2 nanomaterial was well embellished on the surface of the graphene sheets, which helps in electron transfer from TiO2 to graphene and hence interruption by recombination method, to the foremost R-rGO/TiO2/GCE enhance the photocatalytic activity. The electrochemically sensed pesticide intermediate 2,4-DCP was the photo-catalytically degraded by the same R-rGO/TiO2 nanocomposite for water remediation. The nanocomposite exhibits higher degradation efficiency on 2,4-DCP when compared with the individual materials. After the degradation, the degraded water was studied for the animal survival study using Artemia salina as the model eco-toxicology model.

Functionally graded (FG) Al8Si3Cu alloy and 8 wt% titanium carbide (TiC) reinforced composite (∅out100 × ∅56in × 100 mm) was fabricated through horizontal centrifugal casting, followed by T6 heat treatment. Metallographic analysis confirmed fine grain structure at FG alloy outer layers, whereas heat-treated alloy displayed spheroidised eutectic silicon. Gradient microstructure was observed for FG composite. Enhanced hardness for outer layer (10.31%) and tensile strength for outer zone (58.71%) were observed for heat-treated Al8Si3Cu/TiC composite owing to the high concentration of spheroidised eutectic Si and TiC particles, compared to as-cast composite. Linear reciprocating wear analysis performed on as-cast, heat-treated alloy and composite, respectively, at varying load (10–40 N) and sliding distance (500–2000 m) confirmed increasing wear rate, with heat-treated composite having superior wear resistance. Delamination wear was the predominant wear mechanism influencing wear behaviour of heat-treated composite. The alloy and composite were characterized using X-ray diffraction (XRD), energy dispersive spectrometry (EDS), optical microscopy (OM) and scanning electron microscopy (SEM).

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 paper discusses on improving the mechanical and tribological characteristics of homogeneous and functionally graded A359 aluminium alloy processed through gravity and centrifugal casting respectively, through T6 heat treatment. Microstructural observation confirmed uniform and gradient structure for homogeneous and functionally graded casts respectively. Maximum micro-hardness values were observed at 10 hours aging time followed by a significant drop due to over aging. After T6 treatment, 38 and 40 % improvement in micro-hardness, 11 and 13.4 % improvement in tensile strength was observed on comparing as-cast homogeneous and functionally graded material respectively. Wear evaluation was performed for all the regions of as-cast and heat treated functionally graded material and homogeneous casts by varying load (15-35 N) and sliding distance (500-1500 m). Maximum wear resistance was observed for heat treated functionally graded material (outer) under the effect of sliding distance. Wear analysis revealed predominant delamination wear mechanism on worn surfaces.

The present work focusses on improving the mechanical and tribological properties of Al-5Si-3Cu alloy and Ni-coated TiC reinforced composite fabricated through liquid metallurgy route, through T6 heat treatment. Good interfacial bonding was developed between the matrix and coated reinforcement on microstructural investigation. There was an improvement in hardness for heat-treated alloy and composite by 34.5% and 14.7% respectively. Tensile strength for heat-treated alloy and composite was enhanced by 25.9% and 30.6% respectively. Pin on disc dry sliding wear test was carried out for Ni-coated TiC heat-treated composite for varying loads (10, 20, 30N), distances (500, 1000, 1500m) and velocities (1, 2, 3m/s) by using Taguchi's L27 Orthogonal Array. It was concluded that load had the highest influence on wear rate (71.88%), whereas the effects of sliding distance (8.23%) and velocity (3.45%) were nominal. Wear analysis revealed that, wear rate increased with an increase in load and sliding velocity and decreased with increasing sliding distance. Defects like delamination, grooving, and protrusions were observed on the worn surface. Thus, this kind of Ni-coated TiC reinforced composites can be used in camshafts, bearings and bushes for better wear resistance.

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.

Pure copper was coated with Tungsten Carbide-Cobalt (WC12%-Co) using Detonation- Gun technique. A coating thickness of 541 µm was obtained and the hardness of WC-Co coated copper surface was 5.2 times greater than the hardness of uncoated surface. The wear properties of coated copper were investigated using pin-on-disc tribometer, where the WC-Co coated copper exhibited higher wear resistance than uncoated copper. Dry sliding wear properties of WC-Co was analysed using Response Surface Methodology by considering the parameters load (10, 20, 30 N), sliding velocity (0.75, 1.5, 2.25 ms-1) and sliding distance (750, 1250, 1750 m). The results indicated an increase in the wear rate with increasing load and velocity, whereas the increase in the distance showed minimal increase in wear rate. The worn surfaces were analysed using Scanning Electron Microscopy to understand the wear mechanism. The result from the presented experiment may find its application in clutch selector fork of automobile transmission and bearings.

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.

The present study focused on strontium (Sr)-induced A383 alloy and composite reinforced with 6 wt% boron carbide (B4C) particles processed by stir casting technique. From metallographic analysis, it was confirmed that Sr addition modified needle structures of α-Si to fine α-Si. This grain refinement enhanced the hardness of A383-Sr alloy by 52.72% and A383-Sr/B4C by 73.6%, and tensile strength of A383-Sr by 69.93% and A383-Sr/B4C by 81% when compared to A383 unmodified alloy. Fractography analysis proved that both Sr-induced alloy and composite had brittle failure with clear formation of flakes and cleavages. Reciprocating wear test was conducted at various loads (15 N, 25 N, 35 N) and at sliding distances (500 m, 1000 m, 1500 m). It was observed that wear rate was proportional to the applied load. Wear rate increased with increase in sliding distance, but after 1000 m, there was decline in wear rate. Worn surface analysis revealed the presence of oxide layer after 1000 m which enhanced wear resistance. A383-Sr/B4C composite possessed superior wear resistance compared to other.

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).

Functionally graded Cu-10Sn-5Ni/10B4C composite was fabricated using horizontal centrifugal casting. Microstructural and mechanical properties were superior at reinforcement-rich inner zone where w...

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 paper presents the optimization of cutting parameters for MRR, tool wear and surface roughness characteristics in machining of ADC12 alloy. Milling experiments were performed on CNC Milling machine using uncoated carbide inserts. The objective is to minimize the surface roughness, tool wear and maximize the MRR. Process parameters that included speed (1000, 2000, 3000) rpm, feed (0.05, 0.075, 0.1) m/min and Depth of Cut (DOC) of (0.5, 1.0, 1.5) mm were varied for three levels to determine the test cases with the help of Taguchi’s Orthogonal Array (L9), following which, surface roughness, MRR and tool wear was calculated. MRR and tool wear showed similar trends where the responses increase with speed, feed and DOC, whereas the surface roughness tends to increase with feed but lowers on increasing the speed and DOC. Minimum surface roughness and tool wear obtained was 0.25 µm and 0.001 mm respectively, whereas maximum MRR obtained was 0.1144 mm3/min. Speed had major influence on MRR and tool wear whereas, feed had highest impact on surface roughness. ANOVA results also depicted the same rankings. Regression analysis was performed to estimate the surface roughness, MRR and tool wear which was further validated using confirmation tests.

Salmonella enterica is the most pathogenic species frequently responsible for foodborne Salmonella infections in humans. Occurrence of Salmonella enterica in poultry processing lines is a potential risk for the contamination of poultry meat and processing environment. Crosscontamination of carcasses by Salmonella spp. during processing could pose food safety risks. Therefore, the present study involved the detection of Salmonella enterica in the poultry processing lines. The cloacal swabs, caecal contents and carcass rinsates of the birds were collected from processing lines of two processing plants one each from Thrissur and Ernakulam districts of Kerala. The Salmonella spp. were isolated by conventional culture technique on Xylose–lysine deoxycholate agar. The molecular confirmation of Salmonella spp. and S. enterica was carried out by targeting invA and iroB gene, respectively. Out of 450 samples analysed from both the processing lines, 14.22 per cent of the isolates were found to be positive for Salmonella spp. by PCR. The invA gene was detected in 67.19 per cent of the isolates and iroB genes was detected in 81.4 per cent of the Salmonella spp. isolates. Implementation of standard sanitation protocol and hygiene strategies is required to reduce cross-contamination of poultry carcasses.