Materials Science Forum Vol. 969

Abstract: The prepared Polypyrrole/Alumina-Iron oxide nanocomposite has showed 100% adsorption capacity in removing Copper ions from synthetic waste water. The nanocomposite was analyzed using SEM, TEM, FTIR, XRD and EDX. Batch mode adsorption studies were done to check the feasibility of prepared nanomaterial. Adsorption efficiency of the nanocomposite was measured using UV visible atomic absorption spectrophotometry and found 100 % at pH 8. Influence of inceptive Copper concentration, adsorbent dosage, time of contact, temperature, time with dosage, time and concentration were also tested to determine the optimum value in the uptake of Copper ions. Langmuir and Freundlich adsorption isotherm studies were analysed to understand the process of heavy metals adsorption and found best fitted to Freundlich Isotherm.

Abstract: The quest for the lighter materials have motivated the researchers worldwide to develop a newer composites. with the discovery of carbon nanotubes, a class of novel material it has been possible to fabricate the components for the field of automotive and aircraft industries where the strength to weight ratio becomes prominent. In the present work the Al7075 alloy was reinforced with the electroless Ni coated Multiwalled carbon nanotubes in 2wt%,4wt% and 6wt% the nanocomposites were prepared via die casting technique and the resulting composites were tested for the strength and hardness the tensile strength for 6wt% reinforcement found to be 240Mpa a 33% increase compared to unreinforced composite and micro hardness was as high as 61. The SEM analysis revealed that the improvements in the hardness could be attributed to the carbon atoms inclusion in composite lattices.The finite element analysis was carried out for the idealized composite commercial brake rotor the max stress bearing capacity was 172.74 N/mm² and max deformation was 1.85x10^-5 for the 6wt% of reinforcement. Keywords: nanocomposites, die casting, microhardness, aluminium brake rotors.

Abstract: In recent days, it is being found that shape memory alloys can be used in the medicinal field which helps to alleviate numerous disabilities in people. The Shape memory alloy are evaluated for biocompatibility in present work. The objective is to determine the biocompatibility of Cu-Al-Mn SMAs using the alloy of composition 10-14 weight. % Aluminium (Al), 5-9 weight% Manganese (Mn) and rest copper (Cu) through ingot metallurgy in a constrained atmosphere. The casted samples were homogenisation at 900°C for one and half hours and then rolled at 900°C. The rolled specimens were betatized for half an hour at 900°C followed by Step quenching in boiling water (100°C) and quenching in water at room temperature (30°C). They are cut to the dimension of 10 mm * 10mm * 1mm (breadth*length*height) and then effect of shape memory on obtained alloy was assessed. In continuation, in order to understand the biocompatibility of obtained alloy, the samples were analysed for antibacterial movement by turbido-metric process. The microorganisms utilized for biocompatibility are S.aureus and E.coli. The outcomes showed remarkable biocompatibility with the inference that it can be employed for invitrouses.

Abstract: Mg-9Li-3Al magnesium alloys with varied level of Nd added (i.e., 0-2.0wt. %) alloys were prepared electric resistance stir casting furnace under controlled inert gas atmosphere. Impact of Nd addition on metallographical changes and mechanical characteristics of as-cast alloys were analyzed by using an OM, XRD, SEM with EDS. The metallography evaluation revealed that adding Nd refines the microstructures due to formation of Al₂Nd and Al₁₁Nd₃ precipitates, these precipitates exists together with α-Mg, β-Li, AlLi, MgLi₂Al phases in the alloy. Furthermore, adding Nd improves the mechanical strength and elongation. 1.5wt.% Nd added alloy displayed the better mechanical characteristics; UTS is 166MPa; Elongation 16.87%.

Abstract: Copper-Titanium alloy was subjected to multi axial forging (MAF) at cryogenic temperature. Microstructure evolution was observed using optical microscope (OM). After 9 pass of MAF, grain size reduced to 2 µm. As number of MAF pass increases, hardness of the sample increased, due to strain hardening effect. Dry sliding wear test was performed on as-received and MAF processed samples using pin on disc wear machine. Tests were performed at 30 N and 40 N loads at 3 m/s constant speed and at 1000 m and 2000 m, sliding distance. Scanning Electron Microscope (SEM) and EDS was used to analyze the worn-out surface of the specimen. Wear mass loss of MAF processed sample reduced, with increased number of MAF passes. Frictional Coefficient (COF) reduced with increase in MAF passes and improved with increase in load, because of increase in contact area between sample and disc.

Abstract: The present research includes the analysis of mechanical properties of A356/ hybrid metal matrix composite. The mechanical behaviour - hardness, ductility, tensile and yield strength were studied. Reinforcement of these composite specimens were with a weight percentage of (wt - %) 10%, 20% and 30%. The microstructure of these specimens at different wt - % of reinforcements were viewed under an optical metallurgical microscope. It was observed that at 30 wt - % of reinforcement addition, there was a finer distribution of reinforcement particles and as the wt - % decreased, much leaner distribution was observed. The hardness test was carried out using a Vickers Hardness Tester. From the experiment it was noted that with an increase in the amount wt - % of reinforcement, there is a subsequent increment in the mechanical properties except in the case of percentage elongation, which was observed to decrease with an increase in the reinforcement content.

Abstract: From the last few decades, biodegradable composites have become best alternatives over the petro based polymer because these degrade in the simple compound in the natural environments. Among the available biodegradable polymers, polylactic acid (PLA) is more popular due to its biocompatibility and mechanical properties, that can be used in the biomedical application, such as sutures, bone and ligament fixation screws etc. In this study, synthesis of PLA was performed by ring opening polymerization and Calcium phosphate/Polylactic acid (PLA) bio-composites were prepared by melt mixing technique. Tensile properties of these composites are investigated to assess its feasibility in biomedical and food packaging application.

Abstract: Dielectric elastomers belonging to the class of electroactive polymers are promising materials for electromechanical transduction. They are used as actuators, capacitive sensors and energy harvesters. In the present study solid silicone rubber-super conducting carbon black composites are prepared through compression moulding process and evaluated for their mechanical and dielectric properties. Electromechanical sensitivity is estimated and discussed using Taguchi orthogonal arrays for the factors, such as content of active filler and curing agent, mixing time in roll mill, curing temperature. Permittivity of the composites increased 6 times when compared with the sample without active filler. Electromechanical sensitivity of the composite improved 2 times, thus highlighting that this approach could lead to development of newer dielectric elastomer transducer materials.

Abstract: Bronze, an industrially relevant material, is always at a constant need for improvement in its properties. It should possess superior hardness, wear resistance and high tensile properties. The microstructure of the composite was characterized by using an optical microscope. The mechanical and tribological tests were carried out on the developed composite samples as per ASTM standards. It was observed that the hardness of the developed bronze composite increases with an increase in the reinforcement addition. The tensile properties were found to improve with addition of reinforcement particles into bronze matrix but, there observed a decrease in the ductility of the composite as compared to the regular bronze alloy. The wear rate of the developed composite was found to be low as compared to that of the regular bronze alloy

Abstract: In this present investigation titanium dioxide (TiO₂) nano-fluid was blended with aphanizomenon flos (AF) biodiesel (20%)-diesel (80%) blend. Different percentages of TiO₂ such as 5%, 10%, and 15%, was added with AF-D (aphanizomenon flos-diesel) blends. The blends are named as AFD-5TiO₂, AFD-10TiO₂, and AFD-15TiO₂. The performance and emission parameters of a single cylinder CI engine fueled with AFD-TiO₂ blends were experimentally investigated. The results reveal that, with the use of TiO₂ nano particles, AFD-10TiO₂ blend gave optimum results. BSFC decreased by about 5% and BTE increased by about 2% with the addition of TiO₂ nano-particle as a catalyst. The tailpipe emissions such as CO, HC, smoke reduced drastically, but the NO emission increased, with the use of TiO₂ nano-particles.