Applied Mechanics and Materials Vols. 766-767

Abstract: Usage of Hybrid nanocomposite materials provides a greater opportunity to replace the conventional materials due to their properties such as light weight and high strength to based on weight ratio. In this synergitic study, nanosized clay particle and layered double hydroxide particles are used. nanoclay and LDH particles were mixed on the bases of weight percentage (1wt% to 5wt%) by ultra sonication technique. The composite material was fabricated by one of the most common method known as hand lay-up technique. The composite materials was prepared in the form of plate with 4mm of thickness.The characterization of tensile and flexural property of the nanoclay, LDH and combination of both was analysis by tensile test using universal testing machine and three point bending test respectively. The tensile and three point bending test specimens were cut to size as per ASTM standard.The morphology of composite was studied using SEM analysis.

Abstract: Due to high mechanical strength, carbon nanotubes (CNTs) are being considered as nanoscale fibres to enhance the performance of polymer composite materials. The two different types of composite reinforced polymers are fabricated with correct proportions with CNTs for better mechanical efficiency. Two types of CNT-based composites are resin carbon nanotube reinforced and resin glass fiber carbon nanotube reinforced. The reinforced CNT composite polymers are SEM, EDAX and XRD analysed for unified structural stability.

Abstract: Silicon carbide particle (SiCp) of 400 mesh size is coated with Multi Wall Carbon nanoTubes (MWCNT) of 10-20nm diameter and 20-100μm length using sonication process. Scanning Electron Microscope (SEM) is used to verify whether the MWCNT is coated uniformly on the SiCp. Four different samples in which SiCp ranges between 10% and 15% and MWCNT ranges between 1% and 1.5% are prepared and verified using SEM. The percentage of reinforcements was selected on the basis of improved mechanical properties.

Abstract: This paper investigates the effect of nanoclay content on glass fibre reinforced polymer (GFRP) composites under tensile and flexural loading. Four different combinations of GFRP composite panels made of fiber glass/nanomodified polyester resin have been prepared by hand lay-up manufacturing technique (HL). Composite samples are tested for tensile and flexural properties. Scanning Electron Microscopy (SEM) has given morphological picture of the FRP fracture samples. The results showed that the tensile and flexural strength is greatly increased over the range of nanoclay loading by about 23% and 40% respectively.

Abstract: In this present work the effect of reinforcement of hybrid fillers such as nanoclay and carbon black in natural rubber were studied. Sodium bentonite clay was organically modified with octadecyl amine using cation exchange reaction and characterized by FTIR, XRD and SEM. The organomodified clay with 5 phr loading and also with carbon black (CB) of 25 phr loading were incorporated into natural rubber by using a two-roll mixing mill. Vulcanization, mechanical and dielectric properties were studied. Vulcanization and mechanical properties of natural rubber increases on addition of organomodified clay and also with combination of clay and carbon black compared to unmodified clay and gum compounds. Dielectric properties such dielectric constant, dielectric loss and volume resistivity were studied at room temperature and found improved results of the combination of modified clay/CB filled hybrid composites.

Abstract: A composite material is a macroscopic consolidation of two or more materials, having a detectable interface between them. A nanocomposite is the one which consists of two or more nanosized materials which are dispersed in a matrix in order to perk up the properties of the primary material. Polymer composites are prepared by dispersing strengthening fibres in the polymer matrix. A polymer nanocomposite consists of a polymer matrix with nanosized filler. CNTs are one of the most encouraging fillers because of their extraordinary properties and large aspect ratio. A microscopic amount of CNT can have an inquisitively large impact on the properties of a composite. CNTs have been well documented as nanostructural materials that can be used to alter mechanical properties of polymer-based composite materials because of their superior properties. In this research the properties, both elastic modulus and strength of Nylon-66 is improved by the selective addition of CNT. The main objectives include the study of the effect of CNTs content on the mechanical properties of Nylon 66. The composite is to be prepared at various compositions of CNT and material will be analysed by testing the mechanical properties using various test facilities. The finite element modelling of the test specimens were made and a Representative Volume Element (RVE) approach of finite element modelling is used to model the specimen. Mathematical calculations were performed to find out the modelling and RVE. The results are then compared and concluded.

Abstract: An Experimental investigation was carried out to determine performance, emissions and combustion characteristics of diesel engine using nanoaluminum oxide (n-Al2O3) blended diesel fuel. The n-Al2O3 of size 40 nm was blended into diesel fuel. The different dosing levels studied were 250mg, 500mg, 750mg, and 1000mg. Each dosing levels of nanoparticles were mixed with one litre of diesel to prepare test fuels. The n-Al2O3was dispersed by means of an ultrasonic vibrator in order to produce uniform dispersion of n-Al2O3 in the diesel fuel. nanoAl2O3possess better combustion characteristics and enhanced surface-area-to-volume ratio and hence allows more amount of diesel to react with the oxidizer which in turn enhances the burning efficiency of the test fuels. The diesel fuel with and without n-Al2O3 additive were tested in a direct injection diesel engine at different load conditions and the results revealed that a considerable enhancement in the brake thermal efficiency and substantial reduction in content of NOX and unburnt hydrocarbon (UBHC) at all the loads compared to neat diesel were observed due to nanoAl2O3’s better combustion characteristics and improved degree of mixing with air.

Abstract: Present work is focused on Horizontal centrifugal casting process, by which a wear resistant material with considerable strength can be designed. A material of heterogeneous microstructure designed in which a high volume fraction of hard particles is dispersed at the inner surface, where better wear properties are needed, and a gradually decreasing lower volume fraction of hard particles at the outer surface. By this, a better strength and ductility will be achieved at the desired surfaces. The present work is focused on the preparation of cylinder liners using centrifugal casting for Al-17wt%Si. These cylinder liners are characterized for Microstructure, Hardness, Tensile strength and Wear.

Abstract: Experiments were conducted to study the effect of mold material on boundary heat flux variation during gravity die-casting. Inverse method was used for determining heat flux on the inside and outside surface of the mold during casting of pure Aluminum and Al-B₄C composites. Different chill materials were used as mold material on one side of the rectangular mold cavity. K- type thermocouples were used for measurement of mold temperature during casting solidification. The mold temperatures at various locations were recorded using a data logger. These measured temperatures were used as input by the inverse algorithm for the assessment of the surface heat flux as a function of time. It was observed that the temperature difference between the inner and outer surface of the copper is very less in comparison to the cast iron mold and stainless steel mold. The cooling curve of the insulation mold indicates that there is no heat transfer through the insulation mold. The boundary heat flux is much higher in the case of copper mold than in the cases of cast iron mold and stainless steel mold.

Abstract: The present study describes the effects of addition of 4.5 wt% of copper on microstructure and wear properties of cast Al-7Si base alloy. Grain refiner (1 wt% of Al-1Ti-3B) and grain modifier (0.2 wt% of Al-10Sr) were added together to Al-7Si base alloy and Al-7Si-4.5Cu alloy and effect of alloy composition, microstructure and normal pressure on wear properties were studied. Results indicated that combined grain refined and modified Al-7Si-4.5Cu alloys had uniformly distributed α-Al grains, eutectic Al-Si and fine CuAl₂ particles in the inter dendritic region. In both alloys (Al-7Si and Al-7Si-4.5Cu) the wear properties improved after combined melt treatment. The addition of 4.5% copper resulted in improved wear characteristics as compared to both untreated and treated Al-7Si alloys. SEM / EDS analysis were carried out on cast alloys and worn surfaces.