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Aluminum and magnesium alloys are lightweight materials with outstanding technical uses. Due to their combined qualities, composites built of aluminum and magnesium alloys have surpassed the utilization of these elements individually. Accumulative Roll Bonding was used to create a three-layered sandwich composite structure made of Al-alloy/Mg-alloy/Al-alloy. The composite structure's microstructure and mechanical characteristics were studied. A fine-grained AZ31 layer was formed, according to the microstructural study. At the Al-alloy/Mg-alloy contact, a diffusion layer was also seen. On the broken surface, fractography exhibited both ductile and brittle failure characteristics.

In recent years, Air quality monitoring and pollution control is a foremost environmental concern in the world. The World Health Organization estimates 14 million people are affected by air pollution every year. Respiratory and Heart related diseases are mostly caused by air pollutants. Tiruchirappalli is the fourth largest city in the state of Tamilnadu. The study was carried out during the months of December 2018 to March 2019. Ten locations were selected randomly for air quality analysis status for Tiruchirappalli city. The present study aims to develop air quality index, Sulphur Dioxide, Nitrogen Oxides, Respirable Suspended Particulate Matter and Suspended Particulate Matter. The study revealed that the Ariyamangalam area has higher air pollutants than other locations. PM10 and SPM exceeds the permissible limit of NAAQ Standards. SO2 and NOx within limit but continued exposure will lead to health hazards.

Copper matrix incorporated with solid lubricant and hard ceramic reinforcement is a proven potential material for wind turbine brake pad applications. Though brake pads as bulk composites possess high wear resistance, hard ceramic reinforcements at the contact area weaken the joint strength with the brake caliper. This may lead to cataclysmic failure of the mechanical braking. This study aims to develop a functionally gradient materials (FGM) for brake pads that shows variations in composition and properties along its cross section. The brake pad comprises Cu, Fe, hBN, SiC, and Al2O3 powder to obtain a gradient composition profile. Metallographic studies showed the homogeneous distribution of minor matrix (Fe), solid lubricant (hBN), and reinforcement (SiC, Al2O3). Phase analysis was carried out using XRD, and Vickers microhardness tests were performed. A maximum hardness of 133.3 HV was obtained at the top layer of the FGM. Pin-on-disc wear apparatus was used to evaluate the wear-rate and the coefficient of friction (COF) of the sintered specimen at varied loads. Specimens exhibited a low wear-rate of 2.36 × 10−7 g/N m with 0.48 as the COF value at a maximum loading condition (70 N). Surface characterization (morphology, chemical composition, and phase composition) of worn specimens was performed using FESEM, EDS, and XRD analytical techniques. The results inferred that the predominant wear mechanism was oxidative and abrasive wear mechanism at high loads.

Aluminum alloy AA1100 has less wear resistance and mechanical properties than that of other aluminum alloys. This research work is on the fabrication of surface composites of AA1100 alloy by friction stir processing (FSP). The surface composites are fabricated by reinforcing hBN (hexagonal Boron Nitride) in AA1100 alloy to improve the mechanical and tribological properties. The influence of process parameters, rotational speed (rpm), and transverse speed (mm/min) on the microstructural evolution and properties of the fabricated surface composites is investigated.

Brake pads are the major components of the wind turbine, which primarily consists of metal matrix and ceramic reinforcements. The ceramic particles plunge out during the application of brakes, which in turn leads to the transformation of the wear mechanism from adhesive to abrasive wear. This increases the wear rate and therefore the study investigates the possible replacement of ceramic reinforcements with continuous fibers that exhibit high strength and compatibility. In recent years, Cu-based brake pads that are fabricated by powder metallurgy route are widely used in wind turbines. In this study, continuous fibers of stainless steel SS304 are reinforced in the Cu matrix by the casting method to preserve the fiber alignment. The fabricated composite is characterized for microstructure, microhardness, and tribological behavior. Besides, a comprehensive analysis of the wear mechanism in the developed composite is presented based on the surface morphology, elemental composition, and phase analysis.

The study involves the processing of a novel poly [1, 4-phenylene-cis-benzobisoxazole] (PBO) fibre reinforced high-temperature thermoplastic composite with polyaryletherketone (PAEK) as the matrix. The PBO fibre and the PAEK film surface was modified using the method of argon and nitrogen plasma treatment. The investigation primarily focuses on evaluating the tensile properties of the fabricated laminates and correlating it with the effect of plasma treatment, surface characteristics, and its fracture surface. A 5% decrease in tensile strength was observed post argon plasma treatment while a 27% increase in strength was observed post nitrogen plasma treatment. The morphology of the failure surface was investigated by scanning electron microscopy and an interfacial failure was observed. Furthermore, the effect of plasma on the wettability of PBO fibres and PAEK film surface was confirmed by the Dynamic Contact Angle analysis and sessile drop method respectively. FTIR spectral analysis was done to investigate the effect of plasma treatment on the chemical structure on the surface. The results of the wettability study showed that the argon plasma treatment of the fibre surface increased its hydrophobicity while nitrogen plasma treatment resulted in the reduction of contact angle.

Flyash, a residue of coal combustion, is an industrial waste. Flyash is a mixture of toxic chemicals and heavy metals like arsenic, lead, and selenium that is carcinogenic agents. However, more than 65% of flyash produced from coal-powered thermal power plants is disposed of in landfills and ash ponds. Flyash poses a great threat to humans and the environment (groundwater contamination). Hence, waste management is one of the major challenges of coal-powered thermal power plants in India. The project aims at the fabrication of flyash based ceramic tiles by liquid phase sintering technology for industrial and household applications. In this work, the technology for liquid phase sintering of flyash based ceramic tiles is demonstrated. Also, the glazing methodology for flyash based ceramic tiles is optimized. The results indicate that the fabricated flyash based ceramic tiles possess perfect ceramic matrix and glazed surface.

One of the challenges of foundry industries is rejection of casting caused by porosity defects. Of the many factors, proper selection of core manufacturing process has higher impact on the reduction of porosity defects in castings. Cold box core making processes widely used by foundry industries to produce cores because of its good productivity and ability to produce complex designed cores. However, the probability of porosity defect in castings produced using cold box cores is higher than that of other processes. Globally, research is being carried out to solve the porosity defects in castings. However, complexity of the process and involvement of more process variables necessitate identification of root causes of the defects. This work aims at resolving the porosity defect in castings, when cold box core is used. Cores produced by furan core making process, which rarely results in porosity defects, was set as standard for testing the effectiveness of cores produced by cold box core making process. The results indicate that considerably high nitrogen content in the charge raw material in secondary iron making foundries enables reaction of metal with core (binder). Consequently, porosity arises in castings. The remedial measures to control the nitrogen content ensured casting rejections less than 7% in the foundry.

Need for joining similar and dissimilar materials with various thickness and geometry increasing rapidly, inferable from their bit of leeway of light-weighting in the automobile and aviation industries. Brazing is such method expanding quickly with the approach of reasonable high-temperature furnaces incorporated with high vacuum systems. Negligible distortion and restraint of thermal stresses with steady heating and cooling rates make this procedure amiable for joining materials of different size and thickness. In the present study, mild steel brazing was carried out in butt and lap joint configurations using a foil composed of CuSil eutectic (72%Ag28%Cu) to check for reliability in piping and automotive components. Brazing process was performed with varying overlap for lap joints, and butt joint at a constant temperature of 835 °C in a vacuum furnace. Microstructure and elemental composition of the joints were examined using Optical microscope, SEM and EDS. Mechanical properties were investigated at the joint region using micro hardness and tensile strength at room temperature. Results showed that microstructure composed of eutectic Ag and Cu microstructure with no signs of porosity and cracks in the brazed joint. The average hardness of 95 HV in the brazed region is less when compared to the base metal of average hardness 135 HV. It has been found that due to more brazing area, failure occurred away from joints in lap joint configuration, and in brazing joint in case of butt configuration due to micropores and voids.

Copper-based brake pad material is fabricated by powder metallurgy methodology. The developed brake pad material has steel fibers and fly ash as reinforcement to increase the strength and hardness. A methodical approach is followed, where the microstructure is obtained and subsequently the micro hardness values were obtained. After which, wear test is conducted considering various parameters including sliding velocity, normal loads. The tribological parameters namely wear rate and coefficient of friction are evaluated. The wear mechanism of the developed material is deduced from advanced metallurgical characterization. The material is optimized for maximizing the performance by permuting different composition of materials and orientations of matrices.

In recent years, foundries across the globe are oriented towards development of techniques to reduce the adverse effects of foundry waste on the environment. Hence, government enacted stringent procedures on the foundry waste management. Hence, waste management remains a critical factor on the foundry’s economic function. Foundries practice sand molding process for mass production of components, which inherently generate dust and waste. Mechanical reclamation system segregates the molding sand into reusable sand and waste sand. The reusable sand is consequently used for new molding processes, whereas the waste sand is categorized as dust and lumps. The primary objective of this research is to reduce the dust and to reuse the waste sand lumps without compromising the quality of molding sand. Statistical tools are used to optimize mechanical reclamation system. A compatibility mechanization is implemented to convert waste sand lumps into usable sand in line with the standards of American Foundry Society. The results indicate a ∼ 43% reduction in dust generation through optimization of mechanical reclamation system.

Driven by energy conservation and environmental protection, present-day engineering applications focus on the effective usage of fossil fuels. Hence, industrial sectors perform extensive research on light-weighting of structures to improve efficiency. In this study, the aluminum matrix composite (AMC) is fabricated by reinforcing continuous stainless-steel (SS 304) fibers. The fabricated AMC is examined for its mechanical, metallurgical, and tribological properties. The results indicate a 6% enhancement in ultimate tensile strength, a 73% enhancement in hardness, and a 33% enhancement of wear resistance in developed AMC.

AA2014 is a high-strength Al-Cu alloy which is used for highly stressed components in aircraft fuselage, wing covers and military truck frames due to their excellent strength-to-weight ratio, and its properties are usually enhanced by further heat treatment. In this work, the conventional heat treatment process is replaced with shallow cryogenic treatment (SCT) with eight different soaking hours for enhancing the mechanical properties and followed by a tempering process at 160 °C for 18 h. The dislocation effect due to SCT produces volume contraction and grain rotations and shrinking the vacancies and micropores, present in the matrix. Due to the metallurgical behaviour of the strengthening precipitates Theta(θ) phase (CuAl2) and the insoluble particles which are finely dispersed along the grain boundaries of the matrix during the tempering process, results in higher tensile strength, % elongation and fracture toughness. The maximum percentage improvement in microhardness, ultimate tensile strength, % elongation, fracture toughness and wear rate are 40%, 1.28%, 10%, 23% and 48%, respectively, for 18 h of shallow cryogenic treatment, and the property varies for different soaking hours. With these improvements, AA2014 can provide better mechanical properties than the recently developed aluminium alloys with reduced cost.

Fly ash based sintered materials are identified as potential brake pad materials for wind turbines. However, fly ash based friction materials fabricated through conventional techniques results in more porosity and undesirable tribological properties. This study attempts to develop liquid phase sintering technology for fly ash using Cu as a liquid phase sintering agent. The study presents a comprehensive analysis of the evolution of microstructure, microhardness, and tribological performance of the specimens sintered in Argon and Air environment.

Magnesium alloys are widely used to lightweight the components in the automobile, aerospace, and electronics industries because of their low density and high specific strength. However, factors lik...

Magnesium alloy AE42 is a candidate material for high-temperature applications. However, as-cast AE42 alloy exhibits poor high-temperature creep properties because of the microstructure that shows a continuous network of β-Mg17Al12 and Al-RE precipitates along the boundaries of coarse α-Mg grains. In the current work, friction stir processing technique was adopted to refine the coarse as-cast structure of the AE42 alloy and break up the continuous network of β-Mg17Al12 and Al-RE precipitates. The creep properties of the parent material and friction-stir-processed specimens were determined by impression creep test at 150, 175, 200, 225 and 250 °C. The results demonstrated that the presence of fragmented precipitates and the elimination of continuous network structure improved the creep resistance of the AE42 alloy. The metallurgical analysis revealed that no new precipitates were formed after friction stir processing and creep testing. From the data, it can be concluded that friction stir processing of AE42 alloy can lead to an increase in service temperatures from 150 to 225 °C.

Metals like aluminium (Al) and copper (Cu) are excessively used in electrical, automobile, nuclear, and structural applications because of their desirable electrical and mechanical properties. Join...

Phenothiazines are synthetic antipsychotics with a wide range of biological effects. Their properties are determined by the structure and variety of substituents in the heterocyclic system. It is known that various quantum chemical properties have a significant influence on drug behavior in biological systems. Because of the diversity in the chemical structure of phenothiazines and other drugs that include heterocyclic systems, quantum chemical calculations provide useful methods for predicting their effects. This study made an attempt to describe the physicochemical properties and the molecular docking simulation of phenothiazine derivatives. To predict the reactivity of phenothiazine derivatives, DFT-based descriptors including certain highest occupied molecular orbital and lowest unoccupied molecular orbital, energy gap, electronic chemical potential, chemical hardness, nucleophilicity, and electrophilicity were performed by using B3LYP / 6311 ++ G (d, p) level. The most and least active compounds were docked to the protein proteins glycosylphosphatidylinositol phospholipase D inhibitor (1GYM), anaphylatoxin receptor antagonist (6C1Q), arylacetonitrilase inhibitor (3UGC) and aspulvinone dimethylallyl transferase inhibitor (3RIX) to confirm the observations of DFT models and elucidate the mode of binding between this type of compound and the corresponding protein

This study investigated the flow and heat transfer of sodium alginate-based hybrid nanofluids with a stretching/shrinking surface. The heat source/sink, Joule heating, inclined magnetic field, and thermal radiation influences are also examined in the designed model. The mixers of non-magnetic and magnetic nanoparticles are utilized, such as Cu and Fe3O4. The Casson fluid model is applied to determine the viscoplastic characteristics of sodium alginate (SA). The necessary governing SA-based hybrid nanofluid flow equations are solved analytically by hypergeometric function. SA-based hybrid nanofluid velocity, temperature, skin friction, and Nusselt number results are discussed in detail with various pertinent parameters, such as radiation, heat source/sink, inclined angle, magnetic field, Eckert number, and Casson parameters. It is noted that the dimensions of both Cu and Fe3O4 hybrid nanoparticles and Casson parameters are minimized by the momentum surface layer thickness. The magnetic field, radiation, heat source and Casson parameters serve to enhance the thermal boundary layer thickness. Finally, the current result was verified with previously published works.

Composite processing relies heavily on process parameters, which are the key factors that determine the quality of the finished product. In this investigation, carbon fiber (CF)-reinforced polyetherketone (PEK) thermoplastic composites are fabricated through film-fiber stacking and consolidation process. In this method, carbon fabric and polymer film are alternately stacked, and the stacks are then consolidated via compression molding to create a laminate. The mechanical properties of CF/PEK composites are studied in relation to crucial process parameters such as molding temperature, molding pressure, and holding time. To identify the optimal process parameters for CF/PEK fabrication, the tensile and interlaminar shear strengths of these composites were evaluated. Non-linear quadratic equations employing Box-Behnken Design in Response Surface Methodology and validation trials were used to model these features. To obtain the optimal mechanical properties of fabricated composites, the combination of factor ranges was discovered by overlaying contour plots within the practical constraints. The ideal process parameters for achieving maximum mechanical qualities were determined to be around molding temperature of 400°C, a holding period of 60 min, and a molding pressure of 10 bar.

Copper-based brake pad materials with various fractions of praseodymium oxide and yttrium oxide are fabricated through the powder metallurgy processing technique. The influence of praseodymium oxide and yttrium oxide on the microstructure, microhardness, and tribological characteristics of the fabricated specimens are analyzed. The specimen with desired density, high hardness, wear resistance, and optimal friction coefficient is fabricated with gradient layers (pure copper at the brake pad – brake caliper interface and composite at the brake pad – brake disc interface). The result suggested that as the load gradually increases, the wear rate also increases. The surface morphology, elemental composition, and phase composition of the fabricated specimen and worn surface were characterized using advanced instrumental characterization.

In this study, a functionally gradient iron-based brake pad material was developed and the tribological behavior was studied. The functionally gradient specimen had more copper near the base plate and more abrasives towards the top, which provides excellent joint strength and serves the purpose of braking, respectively. The layers had a hybrid composition of metallic materials (Fe, Cu), and abrasives (silicon carbide and aluminum oxide) to improve the strength, wear resistance, and toughness. Graphite was added to stabilize the specimen's thermal and friction characteristics at high temperature. The microstructure, wear rate, and friction coefficient of the functionally gradient specimen and the conventionally sintered specimen were evaluated. The results indicate that the wear resistance of the functionally gradient specimen is higher than the wear resistance of conventional specimen.

The present study aims at developing light weight polymer composite spur gear and improving the performance. Various types of reinforcements and fillers have been used in the polymer gears in order to enhance the performance. There is some evidence in the literature that the metal foamsexhibit significant mechanical properties. The idea here is to use metal foam as a reinforcement material in polymer spur gear and to investigate the performance. The main objective of the present study is to investigate the influence of metal foam properties on the performance of polymer composite spur gear. Two part epoxy adhesive was used to fabricate spur gears. Two different metal foamslike aluminium and nickel with different porosity levels were used in order to have different properties of foams. The epoxy adhesive mixture was cast on the metal foam sheet, and gears were cut by abrasive water jet cutting process after curing of adhesive. The reinforced and unreinforced polymer gears were tested by an indigenously developed gear test rig with standard gear made of mild steel. The testing was carried out at different torque levels and at a constant speed, and the number of cycles was monitored. In the results, the metal foam reinforced gears show better performance than unreinforced polymer gear. In the case of polymer composite gear, nickel foam which has larger tensile strength, flexural strength and smaller porosity level shows better performance comparatively.It is concluded that choosing metal foam with better strength and smaller porosity help us improve the performance of the polymer composite gears.

We study the microstructure and mechanical properties of friction stir processed AZ91D cast magnesium alloy under various conditions of heat treatment. It is shown that, in the initial as-cast state, the structure of the alloy contained a continuously networked β-phase with an average grain size of 150 μm. The friction stir processed (FSP) specimens had an average grain size of 12 μm and smooth grain boundaries. The subsequent heat treatment of the FSP specimens at various temperatures between 150°C and 250°C led to the appearance of numerous particles of the β-phase. The FSP specimens heat-treated at 200°C had finer grains, a larger number of fine particles of the β-phase, and better mechanical properties than any other specimens.