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In this study, an optimization approach was employed to determine the optimal main parameters that improve the performance of functionally graded composites manufactured using a combination of stirring and horizontal centrifugal casting. Pure aluminum reinforced with silicon carbide particles was used as the material for the composites. The effects of key input parameters such as mold speed, pouring temperature, stirring speed, and radial distance were optimized using a combination of grey relational analysis and response surface methodology. The statistical significance of the predicted grey relational grade model was assessed through an analysis of variance to identify the appropriate main parameters. The results showed that radial distance had the greatest impact on the performance of the composites, followed by pouring temperature. The optimal combination of main parameters was determined to be a mold speed of 1000 rpm, a pouring temperature of 750 °C, a stirring speed of 150 rpm, and a radial distance of 1 mm. Confirmation tests using these optimal values resulted in a 54.69% improvement in the grey relational grade.

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.