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Dhanapal A.,Sri Ramanujar Engineering College | Boopathy S.R.,Anna University | Balasubramanian V.,Annamalai University
Materials and Design | Year: 2011

Magnesium (Mg) alloys shows the lowest density among other engineering metallic materials. As a consequence, this light alloy has a promising future. However, these alloys have great affinity for oxygen and other chemical oxidizing agents. The limitation of low corrosion resistance restricts their practical applications. Extruded Mg alloy plates of 6. mm thick of AZ61A grade were butt welded using friction stir welding (FSW) process. Corrosion behavior of the welds was evaluated by conducting salt fog test in NaCl solution at different chloride ion concentrations, pH value and spraying time. Also an attempt was made to develop an empirical relationship to predict the corrosion rate of friction stir welded AZ61A magnesium alloy. Three factors and a central composite design were used to minimize the number of experimental conditions. Response surface method was used to develop their relationship. The developed relationship can be effectively used to predict the corrosion rate of friction stir weld AZ61A magnesium alloy at 95% confidence level. © 2011 Elsevier Ltd. Source


Dhanapal A.,Sri Ramanujar Engineering College | Boopathy S.R.,Anna University | Balasubramanian V.,Annamalai University
Transactions of the Indian Institute of Metals | Year: 2012

Magnesium alloys have gained considerable interest as a material for automotive and aerospace applications due to its low density, high specific strength and good castability. However, an issue is their corrosion properties. This restricts their practical applications. In this work, a comparative evaluation of corrosion behavior of friction stir welded AZ61A magnesium alloy weldments was investigated by immersion and salt spray corrosion tests. Extruded Mg alloy plates of 6 mm thick of AZ61A grade were butt welded using friction stir welding (FSW) process. The specimens were exposed to immersion and salt spray environments in order to characterize their corrosion rates. In addition, an attempt was made to develop an empirical relationship to predict the corrosion rate of the FSW joints in immersion tests and salt spray corrosion tests using response surface methodology. The corrosion morphology and pit morphology observation was carried out by optical microscopy. General corrosion was more prevalent on the immersion surface. However, the pits on the salt spray surface showed larger surface areas, larger volumes, and covered more area on the micrographs as compared to the pits on the immersion surfaces, due to the pit debris that trapped chloride ions within the pits. Finally, it concludes that the FSW AZ61A weldments are suitable for immersion conditions than salt spray environments. © Indian Institute of Metals 2012. Source


Janakiraman R.,Sri Ramanujar Engineering College | Janakiraman R.,Jawaharlal Nehru Technological University Anantapur | Paramasivam S.,ESAB Group
International Review on Modelling and Simulations | Year: 2013

This paper presents simulation approach for the performance analysis of self-excited induction generator (SEIG) for wind power application. The analysis like flux distribution, flux density distribution, and torque and force calculations through 2D finite element analysis (FEA). An induction machine model considered as phase voltage, phase angle calculations through ANSYS simulation. At the beginning, a numerical calculation of the magnetic field distribution of self-excited induction machine, under consideration is carried out. The results of numerical calculations are to be presented through ANSYS simulation and an evaluation of the steady state behavior of the self-excited induction generator is presented for the wind power application. © 2013 Praise Worthy Prize S.r.l. - All rights reserved. Source


Dhanapal A.,Sri Ramanujar Engineering College | Rajendra Boopathy S.,Anna University | Balasubramanian V.,Annamalai University
Transactions of Nonferrous Metals Society of China (English Edition) | Year: 2012

The extruded AZ61A magnesium alloy plates of 6 mm thickness were butt welded using friction stir welding (FSW) process. The corrosion behavior of the welds was evaluated by conducting immersion test in NaCl solution at different pH value, immersion time and chloride ion concentrations. An empirical relationship was established incorporating pH value, immersion time and chloride ion concentration to predict the corrosion rate of friction stir welds of AZ61A magnesium alloy at 95 confidence level. Three-factor, five-level central composite rotatable design was used to minimize the number of experimental conditions. Response surface method was used to develop the relationship. The results show that the corrosion resistance of AZ61A magnesium alloy welds in the alkaline solution is better than that in the acidic and neutral solutions, moreover, low corrosion rate is found at low concentrated solution and longer exposure time, and the corrosion morphology is predominantly influenced by the distribution of β-phase. © 2012 The Nonferrous Metals Society of China. Source


Dhanapal A.,Sri Ramanujar Engineering College | Rajendra Boopathy S.,Anna University | Balasubramanian V.,Annamalai University
Journal of Alloys and Compounds | Year: 2012

Magnesium alloys have gained considerable interest as a structural material for automotive and aerospace applications due to its low-density, high specific strength and good castability. As a consequence, this light alloys have a promising future. The limitation of low corrosion resistance restricts their practical applications. The corrosion behavior of friction stir welded AZ61A magnesium alloy welds was investigated by Immersion technique. Extruded Mg alloy plates of 6 mm thick of AZ61A grade were butt welded using friction stir welding (FSW) process. The present paper reveals the effect of pH, chloride ion concentration and immersion time on corrosion rate of friction stir welded AZ61A magnesium alloy welds in NaCl solution. The corrosion rate was evaluated from weight loss measurements. Furthermore, an attempt was made to develop an empirical relationship to predict the effect of pH value, chloride ion concentration and immersion time on corrosion rate of AZ61A magnesium alloy welds. The corrosion morphology observation was carried out by optical microscopy and the corrosion products were analyzed by SEM and XRD analysis. © 2012 Elsevier B.V. Source

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