Materials Science Forum Vol. 969

Abstract: The study presents the results of the examination on the effect of soaking time on the Microstructure, Grain shape and hardness properties of annealed EN-47 Spring Steel. The EN-47 Spring Steel samples were heated at 860 °C for soaking times of 60, 120, 240, 480 minutes. Optical Microscopy and Rockwell Hardness were carried out to determine the morphology, grain shape and hardness of the material with increasing soaking time. EN-47 Spring Steel samples showed up a decreased value in hardness with the extent of soaking time. Pearlite colonies expand with the increase in soaking time. The linear relationship between the soaking time and other factors were also observed. Keywords: EN-47, Annealing, Microstructure, Rockwell Hardness.

Abstract: Glass substrates are used to deposit thin films utilizing basic and value effective chemical bath deposition (CBD) technique. The films were prepared from the mixture as solutions of manganous acetate tetrahydrate [C₄H₆MnO₄4H₂O] as a manganese source, thiourea [(H₂ N) ₂ CS] as a sulfur source and triethanolamine (TEA) [(HOC₂H₄)₃N] as a complexing agent.In the present paper the deposition was successfully done at 60 °C temperature. The absorption properties and band gap energy were determined employing double beam spectrophotometer. The optical band gap value calculated from absorption spectra of MnS thin film is found to be about 3.1eV.The MnS thin film was structurally characterized by X-ray Diffraction (XRD). The MnS thin film was morphologically characterized by Scanning Electron Microscopy (SEM) and elemental analysis was performed using EDS to confirm the formation of MnS.

Abstract: Abstract.Plastic solar cells are promising devices in looking for low cost and flexible energy storing devices. Low efficiency is the main drawback of these cells in comparison with inorganic solar cells and hence the search for an efficient plastic solar cell has become a globally demanded research problem. In the present work we have used the modified fullerene [6,6]-Phenyl C61 butyric acid methyl ester (PCBM) as N type modulating probe on P type semiconducting polymer Poly[2-methoxy-5-(2’-ethylhexyloxy)-phenylenevinylene] (MEH-PPV). The donor MEH-PPV polymer matrix is modulated by adding PCBM in the weight ratio 1:3, 1:1 and 3:1 in Chloro-Benzene(CB) as the common solvent and glass-coated samples are prepared by solution cast method. Samples are analyzed by UV-VISIBLE spectroscopy by JASCO UV Vis NIR V 670 spectrometer. The effect of PCBM content on MEH-PPV is to broaden the spectral response of MEH-PPV. In other words the acceptor PCBM has tuned the band gap (energy difference between HOMO & LUMO) of the donor MEH-PPV. Spectral analysis revealed that 1:3 blend of MEH-PPV with PCBM has a wide spectral sensitivity for absorption. The band gap for each blend is determined using Tauc’s plot. Increased Fullerene content has decreased the band gap of the host polymer. We conclude that modified fullerene can effectively modulate the donor polymer matrix and 1:3 MEH-PPV: PCBM can act as a good photoactive material for solar cells. Absorption can be further enhanced by either dye sensitization or by metal oxide nanoparticle doping without increasing the thickness of the film. We have doped the optimized 1:3 blend with 20%, 40% & 60% of TiO2 nanoparticles wherein the absorption is enhanced with doping level. The increased absorption is attributed to the photocatalytic activity of the nanaoparticles embedded in the polymer matrix

Abstract: Acrylonitrile Butadiene Styrene (ABS) polymer and Polytetrafluroethylene (PTFE) polymer has different properties individually. In this work ABS is used as matrix and PTFE is used as particle reinforcement. ABS is a copolymer containing butadiene, styrene and acrylonitrile. This work is to focus about the thermal property of ABS copolymer by adding PTFE as particle in polymer composites. From the analysis PTFE fit into a perfect particle reinforcement material for a broad assortment of utilizations. The samples is prepared with 100% ABS and 10% PTFE by weight, 20% PTFE is added to ABS and fabricated with Injection molding process. The addition of PTFE to ABS has improved on thermal properties. Experiment results shows that PTFE filler added composites exhibited high thermal conductivities and good coefficient of linear thermal expansion when compared with pure ABS copolymer.

Abstract: The rapid rise in energy requirement and problem regarding atmosphere pollutions, renewable biofuels are the better alternative choice for the internal combustion engine to partially or totally replace the pollutant petroleum fuel. In the present work, thumba (Citrullus colocynthis) non-edible vegetable oil is used for the production of biodiesel and examine its possibility as diesel engine fuel. Transesterification process is used to produce biodiesel from thumba non-edible vegetable oil. Thumba biodiesel (TBD) is used to prepare five different volume concentration (blends) with neat diesel (D100), such as TBD5, TBD15, TBD25, TBD35 and TBD45 to run a single cylinder diesel engine. The diesel engine's combustion parameter such as in-cylinder pressure, rate of pressure rise, net heat release rate, cumulative heat release, mean gas temperature, and mass fraction burnt analyzed through graphs and compared all thumba biodiesel blends result with neat diesel fuel. The mass fraction burnt start earlier for thumba biodiesel blends compared to diesel fuel because of less ignition delay while peak in-cylinder pressure, maximum rate of pressure rise, maximum net heat release rate, maximum cumulative heat release, and maximum mean gas temperature has found decreased results up to 1.93%, 5.53%, 4.11%, 4.65%, and 1.73% respectively for thumba biodiesel.

Abstract: Proton exchange membrane fuel cell (PEMFC) system is an advanced power system for the future that is sustainable, clean and environmental friendly. The flow channels present in bipolar plates of a PEMFC are responsible for the effective distribution of the reactant gases. Uneven distribution of the reactants can cause variations in current density, temperature, and water content over the area of a PEMFC, thus reducing the performance of PEMFC. By using Serpentine flow field channel, the performance is increased. Two types of serpentine flow field channels are implemented such as curved serpentine flow field channel and normal serpentine flow field channels. The result shows that curved serpentine flow field channel gives better current density and power density, thus increasing the performance of PEMFC.

Abstract: High entropy alloys (HEA’s) have found a very special place in aerospace industries due to their property of forming solid solution. In past literatures on high entropy alloys, it is established that parameters like atomic size difference (), topological parameter (Ω) and electro-negativity difference (∆) plays a vital role in deciding whether solid solution will be formed or not. Therefore, the present study deals with the selection of optimal high entropy composition based on the three parameters δ, Ω and with the help of TOPSIS (Technique for Order of Preference by Similarity to Ideal Solution). Ranking is done for 38 HEA different compositions such that the first rank represents the HEA which is most likely to form solid solution. The study reveals that TOPSIS method can be successfully implemented to predict the formation of solid solution in HEA’s.

Abstract: Concrete largely used for construction material, degrades with the development of cracks that becomes easy passage for entry of chemicals and harmful compounds. Self healing capability is helpful to mitigate the deterioration of the concrete structures. This research work focuses on the self healing behaviour and mechanical properties of the bioconcrete supplemented with three different bacteria namely Bacillus sphaericus, Bacillus cohnii and Bacillus megaterium. Concrete supplemented with Bacillus cohnii exhibited 35.31% increase in compressive strength compared to control mix after 28 days. Concrete supplemented with other bacteria Bacillus sphaericus and Bacillus megaterium also showed enhanced compressive strength. Interestingly, addition of bacteria aided in healing of artificially generated cracks by formation of CaCO₃ minerals. Maximum amount of healing (bacterial precipitation) which could be quantified as calcite minerals present in the bacterial concrete was 11.44% with B. cohnii confirmed by the Scanning Electron Microscope (SEM) with Energy Dispersive Spectroscopy (EDS).

Abstract: Use of nanocomposites is increasing rapidly due to their enhanced thermal and structural properties. In the present work, the numerical modelling of nanocomposites is conducted with the help of the (GA) genetic algorithm and (FD) finite difference techniques to find out a set of nanocomposites with best thermal and structural properties. The genetic algorithm is utilized to find out the best set of nanocomposites on the basis of thermal and structural properties while the finite difference technique is utilized to solve the heat conduction equation. Different nanocomposites considered in the present work are Al-B₄C, Al-SiC and Al-Al₂O₃. The weight percentage of these nanocomposites is varied to see its effect on the nanocomposites properties. In the end, the solidification curve for all the nanocomposites is plotted and analysed. Result reveals that GA helps in identifying the best set of nanocomposites while FD technique helps in predicting the solidification curve accurately. Increment in the wt. % of nanocomposites makes the solidification curve steeper.

Abstract: This research work reports on the investigation on the suitability of prepared Al-Mg binary alloys of hypo-eutectic and eutectic compositions, for making metal matrix composites for light weight applications. Commercial pure aluminium, and magnesium blocks were used for the purpose of making binary alloys of Al-Mg, with the Mg in weight percentages 15%, 20%, 25%, 30%, and 37%. composition prepared by stir-casting under Argon cover gas. The cast Al-Mg alloys were cut to standard specimens to investigate its microstructure and mechanical properties. Test results revealed that the Vicker’s Hardness Number (VHN) of the alloys increases with the increased weight percentage of Mg and Ultimate Tensile Strength (UTS) were also increasing with increasing Mg content. The SEM images revealed the presence of micro-voids in alloys of higher Mg contents. The test values indicates the suitability of hypo-eutectic alloys as candidates for metal matrix composites for light weight applications.