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S. Manikandan ¹, S. Ramanathan ², V. Ramakrishnan ³

Affiliations
1 Department of Mechanical Engineering, Annamalai University, IN
2 Department of Manufacturing Engineering, Annamalai University, IN
3 Thermal Systems Group, ISRO Satellite Centre, Bangalore, IN

Abstract

Ti-6Al-4V titanium alloy is widely used in industrial applications such as aeronautic and aerospace due to its good mechanical properties at high temperatures. The aim of the work is to determine the heat capacity of the thermal cycled titanium alloy. The cylindrical specimens of dimension 3 ± 0.1 mm in diameter and 2.5 ± 0.1 mm in length were machined from the CNC machine. The specimens were subject to two different types of heat treatments (Solution treated and annealed). First type of heat treatment (annealing) is processed by heating the specimen to a temperature of 7500°C for 4 hours and it is cooled in the furnace to reach the atmospheric temperature. Second type of heat treatment (solution treating) is processed by the specimen is heated to a temperature of 975°C for 1 hour and it is quenched in a solution containing water with 5% of caustic soda. After quenching (delay of 6 second), aging was done at 450° C for 4 hours and then it is furnace cooled to reach atmospheric temperature The heat treated specimens were thermal cycled in a specially designed thermal cycling apparatus for different cycles heat flow and the flow of energy into or out of the sample as a function of temperature was measured by using Differential Scanning Calorimetry (DSC). The heat flow response is recorded as a function of actual sample temperature range from -120° C to 380° C. The measurements of the heat capacity by DSC with an accuracy of ±2% have been reported. This study restrict the use of DSC as a truly quantitative calorimetric technique and concentrates mainly on the practical set of experimental heat capacity data measured over a temperature range for different aerospace materials being used/developed indigenously for the Indian Space Programme.

Keywords

Thermal Analysis, Differential Scanning Calorimeter, Specific Heat, Heat Treatment

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S. Ramanathan ¹

Affiliations
1 No Affiliation, IN

Abstract

No Abstract

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S. Ramanathan ¹

Affiliations
1 No Affiliation, IN

Abstract

No Abstract

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S. Saravanan ¹, G. Thimmi Chetty ¹, S. Ramanathan ¹

Affiliations
1 Department of Geology, Presidency College, Madras, IN

Abstract

No Abstract.

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S. Saravanan ¹, S. Ramanathan ¹

Affiliations
1 Department of Geology, Presidency College, Madras, IN

Abstract

No Abstract.

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S. Ramanathan ¹, C. Navaneethakrishnan ¹

Affiliations
1 Department of Geology, Presidency College, Madras, IN

Abstract

Theralites occur as autoliths in nepheline syenites around Pikkili (Δ 2670') in Dharmapuri District, Tamil Nadu. The theralites were emplaced first, followed by the intrusion of different varieties of nepheline syenites.

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S. Saravanan ¹, S. Ramanathan ¹

Affiliations
1 Department of Geology, Presidency College, Madras, IN

Abstract

The plagioclase - pyroxene - garnet rocks, occurring in the Manalur area, have been designated as 'meta-anorthosite' by Murthy (1959). The authors however, consider them as a member of meta-sedimentary group of Archaeans which have resulted from the metamorphism of calcareous sediments of varying compositions. Since there is a general misconception among some of the Indian petrologists, who consider these metasedimentary calcareous members as 'anorthosites', it is proposed to deal with these rock types, in order to show that they have no association with anorthosites, which are one of the members of the layered complex.

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S. J. Keny ¹, A. G. Kumbhar ¹, A. Sanjukta ², S. Pandey ², S. Ramanathan ³, G. Venkateswaran ²

Affiliations
1 Water and Steam Chemistry Division, Bhabha Atomic Research Centre, Mumbai 400 085, IN
2 Analytical Chemistry Division, Bhabha Atomic Research Centre, Mumbai 400 085, IN
3 Material Science Division, Bhabha Atomic Research Centre, Mumbai 400 085, IN

Abstract

In nuclear power plants corrosion and activation of structural material and its re-deposition on out-ofcore surfaces is of significance as far as structural integrity and radiation exposure to the employees are concerned. Recently, Indian Pressurized Heavy Water Reactors have faced a typical problem of activation of antimony (Sb) from primary heat transport pump seals containing ∼10% Sb. This Sb cannot be removed easily and its deposition mechanism is yet to be clearly understood. This article deals with studies related to the understanding of this process and a solution for the removal of Sb.

Keywords

Antimony, Absorption and Removal, Carbon Steel, Magnetite, Pressurized Heavy Water Reactors.

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S. Krishnamohan ¹, S. Ramanathan ², S. Velmurugan ¹

Affiliations
1 Department of Mechanical Engineering, E.G.S Pillay Engineering College, Nagapattinam, Tamilnadu, 611 002, IN
2 Department of Manufacturing Engineering, Annamalai University, Annamalai Nagar, Tamilnadu, 608 002, IN

Abstract

Nanocomposites are composites that consist of nanosized particles embedded in some type of matrix are a group of promising new materials that will undoubtedly become infused with some of our modern technologies. Material property combinations and ranges have been, and are yet being, extended by the development of composite materials. Already Titanium is recognized for its strategic importance as a unique lightweight, high strength alloyed structurally efficient metal for critical, high-performance aircraft, such as jet engine and airframe components. Due to its high strength-to-weight ratio, Titanium is called as the "space age metal". Today, titanium alloys are common, readily available engineered metals that compete directly with stainless and Specialty steels, copper alloys, nickel based alloys and composites. In order to reduce residual stress developed during fabrication and to increase the strength a new composite material of Titanium (Ti-6Al-4V) Alloy with Nano SiC are needed. This composite also is an alpha beta alloy which is subjected to annealing and solution treatment to attain beta phase. This beta phase is maintained by quenching and subsequent aging to increase strength. Thermal cycling process was carried out for heat treated composite specimen. This paper reports on the investigation of tensile behaviour of different Heat treated and thermal cycled composite material of Titanium (Ti-6Al-4V) Alloy with Nano SiC and the micro structural changes. Also the tensile behaviour is compared with the ordinary Titanium Alloy.

Keywords

Stir Casting, Thermal Cycling, Heat Treatment, Solutionizing, Aging, Tensile Strength.

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S. Krishna Mohan ¹, S. Ramanathan ²

Affiliations
1 Department of Mechanical Engineering, E.G.S. Pillay Engineering College, Nagapattinam, Tamil Nadu – 611002, IN
2 Department of Manufacturing Engineering, Annamalai University, Chidambaram, Tamil Nadu, IN

Abstract

Silicon carbide powder (SiCp) was milled in a high energy ball mill in 350 rpm for 8 hrs. The wet milling media was tungsten balls (WC) in chemical compound Toluene (C6H6-CH3).The milled powder then characterized by Atomic Force Microscope (AFM) to study topography and particle size analyzer.

Keywords

Atomic Force Microscope, Particle Size Analyzer, Planetary Mill, Silicon Carbide and Synthesis.

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M. Rajamuthamilselvan ¹, S. Ramanathan ¹

Affiliations
1 Department of Manufacturing Engineering, Annamalai University, Annamalai Nagar-608002, Tamilnadu, IN

Abstract

The hot deformation behaviour of 7075Al/20%SiC (5μm) particulate reinforced metal matrix composites was studied by using processing map technique. The map has been interpreted in terms of the microstructural processes occurring in situ with deformation, based on the values of a dimensionless parameter (η) which is an efficiency index of energy dissipation through microstructural processes. An instability criterion has also been applied to demarcate the flow instability regions in the processing map using another parameter (ξ). Both the parameters (η and ξ) were computed from the experimental data generated by compression tests conducted at various temperature and strain rate combinations over the hot working range (300-500°C and 0.001-1 s-1) of the present material. The processing map exhibits two distinct η domains without any unstable flow conditions under the investigated temperature and strain rate conditions. The dominant microstructural mechanisms corresponding to these domains were identified to be extended dynamic recrystallization and flow localization. The 'stable' and 'unstable' regions in the processing maps were identified and compared with the reported microstructural observations of the deformed compression specimens. The optimum hot working conditions for these composites are suggested.

Keywords

Metal-Matrix Composites (MMCs), Hot Deformation, Dynamic Recrystallization, Processing Map.

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S. Manikandan ¹, S. Ramanathan ², S. Krishnamohan ³, D. Vasudevan ¹

Affiliations
1 Department of Mechanical Engineering, Annamalai University, Annamalai Nagar-608002, Tamilnadu, IN
2 Department of Manufacturing Engineering, Annamalai University, Annamalai Nagar-608002, Tamilnadu, IN
3 Department of Mechanical Engineering, E.G.S Pillay Engineering College, Nagapattinam-611002, Tamilnadu, IN

Abstract

Titanium is recognized for its strategic importance as a unique lightweight, high strength alloyed structurally efficient metal for critical, high-performance aircraft, such as jet engine and airframe components. Titanium is called as the "space age metal" and is recognized for its high strength-to-weight ratio. Today, titanium alloys are common, readily available engineered metals that compete directly with stainless and Specialty steels, copper alloys, nickel based alloys and composites. Titanium alloys are needed to be heat treated in order to reduce residual stress developed during fabrication and to increase the strength. Titanium (Ti-6Al-4V) alloy is an alpha beta alloy which is subjected to annealing and solution treatment to attain beta phase. This beta phase is maintained by quenching and subsequent aging to increase strength. Thermal cycling process was carried out for heat treated Ti-6Al-4V specimens. Forced air used for cooling. This paper reports on the investigation of tensile behaviour of different Heat treated and thermal cycled Titanium (Ti-6Al-4V) alloy and the micro structural changes.

Keywords

Thermal Cycling, Heat Treatment, Solutionizing, Aging, Tensile Strength.

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S. Krishna Mohan ¹, M. Raja Muthamil Selvan ², S. Ramanathan ², S. Vijaya Priya ¹

Affiliations
1 Department of Mechanical Engineering, E.G.S. Pillay Engineering College, Nagapattinam, IN
2 Department of Manufacturing Technology, Annamalai University, Chidambaram, IN

Abstract

In this study 7075 matrix alloy is chosen and SiC particles having average particle size of 20 μm with four volume fractions of 10%, 15% and 20% and 30%. were incorporated into the alloy at the liquid state Stir casting followed by extrusion. Tensile, Impact, Hardness test were carried out both alloy and composites. The 15 Vol.% SiCp aluminum matrix composites showed the maximum tensile and Yield strength. The results indicate that extrusion can substantially improve the distributed homogeneity of the SiC particles in the matrix, and help to decrease the number of pores and improve interfacial bonding strength of the composites. The yield strength and tensile strength of the composites decrease with increasing the volume fraction of the SiC particles, while the hardness of the composites increases with increasing the volume fraction of the SiC particles. The hardness increases with the aging time until reaching the maximum values, after which the hardness starts to decrease.

Keywords

Matrix Alloy, SiCp Aluminium Matrix Composite, Stir Casting, Yield Strength.

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R. Rajarajeswari ¹, K. Vijayakumar ¹, P. Rahul Swaroop ¹, S. Ramanathan ¹

Affiliations
1 Department of Electrical and Electronics Engineering, SRM University, Chennai – 603203, Tamil Nadu, IN

Abstract

Objective: To design controllers for AC micro grid. To improve battery span, fuzzy control and energy management control the charging and discharging mode of the battery. Methods: A fuzzy controller can be used for the control of battery SOC of the renewable hybrid system and Energy Management Control is also used as above and to improve the performance of the system. Findings: The wind, solar hybrid power system plays a vital role today in renewable energy resources because it uses solar and wind power combined to create a stand-alone energy source that is both dependable and reliable. Conventional approach cannot provide with best way of energy management due to its non-linearity of battery charging process. So modern controllers are used in micro grid for battery SOC control. Improvement: In this work both fuzzy logic controller and EMC system is used for the hybrid system modeled using solar, wind and fuel cell system.

Keywords

Energy Management System, Fuzzy Logic Control, State of Charge.

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K. Natarajan ¹, S. Ramanathan ¹, R. Sathish ¹, C. Amudhadevi ¹

Affiliations
1 Department of Pharmaceutical Biotechnology, Ultra College of Pharmacy, Madurai, IN

Abstract

Many marine origin organic molecules entered clinical studies for anticancer therapy. Ascidians, a marine invertebrate animal draw attention of the researchers for its versatility as medicine and nutrition. In this study methylene chloride crude extract of Polyclinum madrasensis Sebastian (Ascidaciae) was tested for its in-vitro anticancer property on HeLa cell lines (cervical cancer cell lines) using MTT assay. Results revealed that the extract exhibits cytotoxic effect on the cell lines used (IC 50- 0.23mg/ml). Extract was further elucidated using chemical and spectral analysis (IR, HNMR), in which peptides were found to be the major constituent. As a conclusion, Polyclinum madrasensis is found to be a good source for drug lead component in cancer drug discovery process.

Keywords

Polyclinum madrasensis, PME, Cytotoxicity, HeLa.

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N. Veman Reddy ¹, S. Ramanathan ¹, Ammineni Syam Prasad ¹

Affiliations
1 Department of Mechanical Engineering, MVSR Engineering College, Hyderabad, A.P., IN

Abstract

The vital stage in manufacture of castings is the formation of solid casting from molten metal when poured into mould cavity. The various complex transformations that occur during the process influence the quality of the casting. The design of risering system which ensure freedom from shrinkage and other solidification oriented defects in the casting play a vital role in the quality and yield of the casting. A good design will produce castings free from these defects and considerably improve the yield. this paper describes the removal of shrinkage defect in Ductile Iron casting by redesigning the risering system using Virtual casting simulation software MAGMASOFT and CAD software PROENGINEER.

Keywords

Ductile Iron, Risering System, Casting, Shrinkage, Simulation, Modulus.

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S. Ramanathan ¹, R. Karthikeyan ¹, B. Senthil Kumar ¹, B. C. Pai ¹

Affiliations
1 Department of Manufacturing Engineering, Annamalai University, Annamalainagar - 608 002, IN

Abstract

Powder metallurgy remains a promising route for the manufacturing of Metal Matrix Composites (MMCs) with desirable properties, in this paper an attempt has been made to manufacture MMCs through powder metallurgy route and compression testing was performed on the MMCs. The aluminum (99% pure aluminum) metal matrix composites with 15% volume fraction of SiC (green bonded 25m size) were produced through powder metallurgy technique. The mixture of composite powders with graphite binder was first cold pressed and then vacuum hot pressed to attain the required density. The green compacts were further sintered in vacuum atmosphere to produce MMCs. The specimens 20 mm diameter by 20 mm length were hot pressed for a range of temperatures (300 -5007C), strains (0.1 -0.5) and strain rates (0.0087 /s to 2.7 Is). The true stress-true strain curves were drawn for the different testing conditions. Strain rate sensitivity, power dissipation efficiency, and instability parameter were estimated and processing maps were developed for 0.1 and 0.5 strains for AiH5% SiC composites. The optimum working regions were identified and validated through microscopic examination.

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