A comparative study on effects of quenching and aging process on tribological properties of Al-6061 based hybrid composite


Heat treatment process is widely used to improve the strength and wear properties of casted aluminium alloys. In this investigation, aluminium (Al 6061) matrix hybrid composites were produced with particulate reinforcement of zirconium dioxide (ZrO2) and graphite by gravity stir casting technique. Reinforcements with a grain size of one hundred microns (100 μ) were considered to produce the test specimens. AMCs were produced considering the graphite reinforcement constant as 1% of the total weight of the component and varying the percentages of zirconium dioxide from 1 to 6%. The specimens so produced were subjected to sequence of heat treating operations which includes quenching and aging process. Hardness and dry sliding wear characteristics were evaluated. It was observed that the results produced by the specimens with heat treatment particularly ice quenched gives better wear characteristics when compared to the specimens without heat treatment.
Keywords: Al 6061, zirconium dioxide, quenching process, wear

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A comparative study on prediction of wear properties of Al6061 based hybrid composite using artificial neural network and finite element method


Engineering materials are commonly defined and designated by their properties. The present work investigates tribological characteristics of aluminium 6061 based metal matrix composites (MMC’s) in combination with zirconium dioxide (ZrO2) and graphite (Gr). Prediction models using artificial neural networks (ANN) and finite element method (FEM) are also used to correlate wear parameters, ANN prediction is comparatively more accurate compared to FEM. To make the work easier in predicting wear, a graphical user interface (GUI) is prepared. This study has shown the ability of ANN as a good analytical tool which can be efficiently utilized in the field of tribology
Keywords: Aluminium 6061, zirconium dioxide, artificial neural network, finite element method

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Design fabrication and analysis of gearbox using labview


Automobile has become an integral part of the day to day activities. Hence the use of bikes and cars has seen a drastic increase in usage in the past decade. Especially in India the usage of bikes surpasses the usage of cars.Usage of the bikes for a prolonged period of time results in the wear of the gears used in the automobiles. Since the gears used in the bikes are spur gears the project is carried out using the spur gear. Our project deals with the condition monitoring of the gear using the labview software. The project consists of a gear set up which is connected to the piezo electric sensors which in turn is connected to the microcontroller set up. The micro controller is connected to the computer using the serial adapter and using the labview software the graph of the amplitude is plotted using the vibration obtained from the piezo electric sensors. From the graph the danger level of the gear is determined using a scale from maximum to minimum. The minimum being the gear at the least worn out and the maximum being the gear at high level of wear. This method completely takes the vibration of the gears and converts it into the amplitude graph and the readings can be noted to find the gear wear detection. Using this method the gear wear can be determined without the opening of the case of the gear. The software can be used to alert the user to change the gear before the complete damage of the gear takes place.
Keywords: Spur gear, condition monitering, wear

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Evaluation and selection of green supplier using fuzzy TOPSIS – a case study


In recent times every manufacturing industry realizes and recognizes the need for green production to protect the environment and to fulfil the environmental conscious customer requirements using different strategies. Green supplier selection is one of the approaches to achieve these goals. However selection of green of supplier is influenced by the various criteria chosen. In order to minimize the gap between perceived and actual selection of suppliers, Fuzzy TOPSIS method has been attempted to find the solution using a case study approach in textile industry.
Keywords: Fuzzy TOPSIS

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Experimental analysis on tribological performance of dimpled textured surfaces on a frictional pairs


Dimple texture forming in the frictional pairs is one of the friction reduction techniques like lubrication. The geometrical shape and area density ratio of the dimple texture features play an essential role in improving tribological performance of the frictional pairs. In this work, the frictional properties of the brass discs with three kinds of laser surface textured (LST) surfaces (smooth, circular arrays of spherical and ellipsoidal dimple features) with various area densities, mated on cylindrical shape brass pin were calculated using a pin on disk tribometer. Results also indicated that spherical shape dimple patterning comparatively outperforms the ellipsoidal shape dimple patterning and reduces the coefficient of friction (CoF) by 14.5% under dry lubrication.
Keywords: CoF, dimple texture, friction, LST, tribometer

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Experiments on high speed CNC machining to optimize the parameters for enhancing the surface quality of (AA6063-T6) aluminium alloy components

Dec 2017 / by R. SUBBAIAH, N. M. SIVARAM and P. SENTHIL

This paper elucidates the influence of optimization of CNC machining parameters namely cutting speed, depth of cut, nose radius and feed rate on the surface roughness of AA6063-T6 aluminium alloy. Experimentations were carried out based on the orthogonal array (L9)and surface roughness was tested on the aluminium alloy components turned by a high speed CNC turning centre. Analysis of variance (ANOVA) was performed to predict the significant parameters influencing the surface roughness. Taguchi method was engaged to optimize the CNC machining parameters for optimum surface roughness of the machined components. The optimum parametric conditions were verified with a confirmation experiment.
Keywords: AA6063-T6 aluminium alloy, high speed CNC turning, surface roughness, Taguchi method

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FML GLARE 3 under bending loading conditions – a comparative numerical analysis

Dec 2017 / by D. SATHISHKUMAR and S. ARAVIND

This paper examines the numerical investigations on bending behaviour of different glass fiber reinforced aluminium (GLARE) FML (Fibre metal laminates) plates and their performance was compared to composite unidirectional E glass fiber plates of same thickness. Numerical analysis was done by using ANSYS 15.0 software with the validated procedure. In the present numerical analysis, linear layered structural Shell 181 element is used to model the FML and composite plates. From the numerical results, the graphs were plotted for pressure versus deflection, pressure versus stresses for varying loads applied to plates made of Glare and composite. It was observed that the cross ply laminated plates Glare 3(3/2) offered the least shear stress when compared to Glare 1 and Glare 2. The results show that the maximum central deflections in Glare 3(3/2) is about 83% lesser than that of composite. From this analysis, we have found that the strength of the Glare 3 (3/ 2) is higher than that of composite materials. The deflection and stresses can be predicted for various loading conditions of the FML Glare using this analysis.
Keywords: Aluminium alloy sheets; ANSYS; fiber metal laminate (FML), Glare (glass fiber reinforced aluminium), hybrid composites

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Heat flow analysis of a differentially heated enclosure using CFD

Dec 2017 / by E. VISHWANATHAN and S. ARAVIND

Computational fluid dynamics is a tool used by many industries for CAE analysis of flow related problems. CFD can be used for external or internal flow analysis. In this present work, CFD analysis for external flow over a heated enclosure is performed. For this analysis, Twilight enclosure assembly, which is used for automatic ON and OFF of street lights using sensors, is selected. This equipment is placed in open atmosphere exposed to sunlight throughout the day and the equipment is heated because of radiation effects. As there are many sensitive parts inside the enclosure (parts like sensors and other electronic equipment), they also get heated through the radiation and conduction process. Since air flow is present throughout the environment, the natural cooling of the equipment can be carried out without any much cost involvement. In order to provide the solution to this problem, numerical analysis using CFD for the heat transfer through radiation and convection and optimization of the convective heat transfer by varying physical structure of the enclosure is performed. For this heat transfer analysis, SolidWorks Flow Simulation is used and SolidWorks for modeling. The analysis resulted with a considerable solution that the natural convection enhancement has certainly increased the rate of heat transfer in the enclosure. This applied to the reality would increase the life of the electronic components in the enclosure.
Keywords: CFD analysis, closed enclosure, natural convection, SolidWorks, Simulation

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Mechanical properties of open-cell aluminum foam manufactured through stir casting using CaCO3 as foaming agent and NaCl as infiltrant


Stir casting and infiltration are the methods employed in manufacturing the closed and open cell A413 (LM06) aluminum foam. The aluminum foam has the potential to act as an absorber material in engineering applications. In this present study, initially A413 aluminum alloy is mixed with different quantity of calcium carbonate (CaCO3) as a foaming agent to form closed cell aluminum foam. Later, A413 aluminum alloy is mixed with different quantity of sodium chloride (NaCl) particles which act as a space holder to fabricate the open-cell aluminum foam using infiltration method. A413 alloy was allowed to heat up to 700oC in a crucible to the molten state. In the molten state, preheated CaCO3 of 5%, 10%, and 15% was added and stirred to form closed cell foam of A413 alloy. Similarly, NaCl of 5% 10%, and 15% was added to A413 alloy and heated up to 800°C in the die under vacuum. The argon was supplied to the die after A413 alloy attains the melting temperature. The open-cell aluminum foam was formed. Properties such as density, the percentage of porosity and microstructure were analyzed for A413 alloy foam when both CaCO3 and NaCl were added to it. The study revealed that the addition of the NaCl as space holder increases the percentage of porosity and decreases the density of the foam in comparison with CaCO3. The NaCl space holder resulted in a better quality of open-cell aluminum foam.
Keywords: Aluminum foam; foaming agent; infiltration; microstructure; space holder

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Numerical analysis of protection wall of lambda sensor with modified design of protection wall using CFD

Dec 2017 / by S. ARAVIND and E. VISHWANATHAN

Automotive lambda sensors (ALS) (oxygen sensors) made the possibility of digitally controlling the modern electronic fuel injection and emission control systems. In the present work, a CFD analysis was performed to modify the design of the protection wall of the ALS to extend the life time. The analysis results revealed that the modified design of the protection wall was better than the existing protection wall of ALS. The computation results also showed that the pressure at which the exhaust gas entering the ALS decreased by about 1.36% when compared to the existing design. The pressure at the core of the ALS decreased by about 10% for the modified protection wall. The pressure of the exhaust gas leaving the ALS was decreased by about 6.5% when compared to existing design. The velocity of the exhaust gas at the entry and core of the ALS decreased by about 20% and 16.7% respectively when compared to the present protection wall design. The temperature of the exhaust gas at the core of ALS decreased by about 14.8%. These computationally analyzed results for the modified design of the protection wall of ALS on implementation definitely increases the life span of the ALS from the existing life time of 2,50,000 km or 15 years which ever reaches first.
Keywords: CFD; Lambda sensor; Protection Wall; Pressure; Temperature

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