Applied Mechanics and Materials Vol. 591

Abstract: The present work focuses on the fabrication of aluminum (6061-T6) matrix composites (AMCs) reinforced with various weight percentages of SiC particulates using sand casting method. The addition of Mg in the melt during the process has improved the wettability between Al and SiC there by reduced the formation of SiO₂ layer on the surface. The fabricated AMCs were characterized using optical microscopy (OM), scanning electron microscopy (SEM), hardness tester and universal tensile testing machine. The OM and SEM images revealed the presence of homogeneous dispersion of SiC particle in the matrix. Using X-ray diffraction (XRD) test, the dispersion of reinforcement has been identified. With the increases in weight percentage of SiC particles in the aluminum matrix improved the mechanical properties of composites.

Abstract: Leaf springs are the traditional suspension elements, occupying a vital position in the automobile industry. This paper deals us the replacement of existing steel leaf spring by composite leaf spring. The dimensions of existing middle steel leaf spring of commercial vehicle (Tata ace mini truck) were taken and fabricated using a specially designed die. Single leaf of the suspension springs, each made up composite with bidirectional carbon fiber reinforced plastic (CFRP), bidirectional glass fiber reinforced plastic (GFRP) and hybrid glass-carbon fiber reinforced plastic (G-CFRP), was fabricated by hand layup process. It is to be mentioned here that the cross sectional area of the composite spring same as the metallic spring. A low velocity impact test rig was fabricated in the laboratory with loading set up. The composite leaf springs were tested with the low velocity impact test rig. By using the low velocity impact test rig, the deflection due to various drop height were measured.

Abstract: The corrosion behaviour of Al (6061)-B4C-Graphite was investigated. The Aluminium Metal Matrix Composites (AMMC) was fabricated through two step stir casting method. The composites were fabricated with various volume percentages of Boron Carbide (5, 10 &15%) and Graphite (5, 10& 15%). Corrosion studies of AMMC was investigated with 4%, 8%, 12% wt. % NaCl solution at room temperature. Also erosion-corrosion test were performed on the specimens in the NaCl solution with silica sand. Erosion-corrosion tests indicated that the rate of material loss mechanism is mechanical abrasion with enhanced corrosion. The material loss mechanism was significantly higher in the case of erosion-corrosion tests.

Abstract: Formability of AA6061 T4 mainly depends upon the physical and mechanical properties of the materials. This study focuses on the effect of annealing at different soaking temperature with furnace cooling conditions. Effects are investigated at three orientations 0o, 45o, and 90o to the rolling direction of sheet metal. The value of plastic strain ratio and strain hardening exponent at three orientations were evaluated.

Abstract: In recent years, many researches focused on the polymer materials to study the characteristics and to enhance the mechanical properties of the nanocomposites in order to understand the factors which lead to the desired dispersion of nanoclay in the polymer matrix. The samples used in this work were prepared through melt compounding, using high-density polyethylene and organo-modified clay of montmorillonite (MMT). During manufacturing of MMT/HDPE nanocomposites, a silane modifier and polyethylene grafted with maleic anhydride (compatibilizer) were added to get good surface finish and to act as bonding agent respectively. In addition, the compatibilizer will help in attaining better intercalation. Using a Plastograph-Mixer through twin-screw extruder, the high density polyethylene and different weight percentages (0, 1, 2, 3, 4 wt. %) of MMT are mixed and subsequently the composite is produced in the form of solid material. ASTM standard specimens for various tests are produced using injection molding machine with respective dies. The prepared experimental specimens for various tests like tensile, flexural, impact and shore-hardness are tested for its respective strengths. From this investigation, it is concluded that the addition of MMT nanoclay in HDPE has significantly influenced the mechanical properties of the composites.

Abstract: Plain GFRP, copper wire embedded GFRP and SMA short fibres included copper wires embedded GFRP laminates have been prepared by hand lay-up method. The mechanical properties like flexural and tensile strength were investigated. To study the impact properties of the laminates an experimental set up was designed and the impact strength of the laminates was studied by drop weight method. Three point bend method was adopted for flexural studies and the tensile strength was found by Instron Machine. It is found that the inclusion of SMA short fibres significantly improved the mechanical properties of the composites.

Abstract: In a perspective of stable industrial development to manufacture added consistent and economical industrial product, gears are ever more focus to requirements in terms of power capability, efficiency and compactness etc. In order to increase the performance factors of gears such as transmission capacity, efficiency, gear life, etc. is a difficult criteria for a design engineers as these are all progress in a conflicting behavior. This paper deals with the multi-objective optimization of spur gear drive design with two contradictory objective functions such as maximization of power transmission and minimization of volume of the gear drive. These objectives are approached by an optimization technique based on a Sheep Flocks Heredity Model Algorithm (SFHM) with design constraints like stress, center distance etc. A spur gear problem is solved with traditional trial method and results are compared with proposed algorithm.

Abstract: This paper deals with the fabrication of test specimens of Glass fiber reinforced plastic (GFRP), Carbon fiber reinforced plastic (CFRP), Glass-Carbon fiber reinforced plastic (G-CFRP) and Carbon glass fiber reinforced plastic (C-GFRP) by using hand layup method. The low velocity point load setup was fabricated and fixed in the milling machine by using cam pointer arrangement. The specimens have been subjected to the low velocity point load for specific duration by exposure time such as 0,15,30,45 and 60 minutes. Then impact and DMA tests are also carried out for the above specimens. From the DMA test results it was found that the storage modulus and loss factor of GFRP specimen are high compared with others. Izod impact test result shows that impact strength of G-CFRP specimen is high. The flexural results reveals that among the four types of laminates CFRP gives higher order of flexural strength and modulus compared to the others

Abstract: A new approach was attempted to prepare a chemically modified electrode using copper hexacyanoferrate (CuHCF) nanoparticles as the redox mediator and to study its stability and electrocatalytic activity for ascorbic acid (AA) oxidation. The CuHCF modified electrode was prepared and characterized using cyclic voltammetry. The effect of scan rate, supporting electrolyte and pH of the medium on the performance of the modified electrode was investigated. The CuHCF modified electrode exhibited good electrocatalytic activity towards the oxidation of ascorbic acid and gavea linear response4×10⁶ M to 4.9×10^-4M with a correlation coefficient of 0.995). Hydrodynamic voltammetry and chronoamperometry studies for the oxidation of ascorbic acid were also carried out. The electrode was highly stable and exhibited good reproducibility. This modified electrode was also applied for the determination of ascorbic acid in commercial samples.

Abstract: Influence of surface roughness on coefficient of friction of Titanium coated R19 Steel is investigated in this paper using Pin on Disc Apparatus. Wear properties of R19 Steel are evaluated because it is widely used in making the rail wheel and rail roads over the years. Titanium coating of 100nm thickness was deposited on the R19 Steel by Electron Beam Gun Physical Vapor Deposition method. Wear and friction parameters were evaluated using Pin on Disc apparatus. The Surface morphology plays an important role in affecting the wear rate. Non-contact surface roughness tester was used to examine the surface texture and measure the surface roughness of the specimens. The test was carried out in a pin on disc apparatus for Normal Load of 15N, Sliding Velocity of 3m/s and Time 5 min. The texture and the roughness parameters of the surface affect the coefficient of friction. The experimental values of roughness parameters of uncoated and coated disc and its effect on coefficient of friction are compared and validated. Results show that the Coefficient of friction decreases with lower value of R_a. Lower values of frictional force and coefficient of friction results in lower wear rates.