Vellore Institute of Technology (VIT) is a private university located in&nbsp;Tamil Nadu, India. Founded in 1984, as Vellore Engineering College, the institution offers 20 undergraduate, 34 postgraduate, four integrated and four research programs. It has campuses in Vellore, Amravati, Bhopal and Chennai.

VIT is one of the top ranked private universities in India according to NIRF, THE and QS Rankings.&nbsp;Govt. of India has recognized&nbsp;VIT, Vellore as an&nbsp;Institution of Eminence. This has allowed VIT to take independent quality initiatives and move up in world ranking.

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VIT University

World University root node

Mechanical

School of Mechanical Engineering

Chennai Campus

Advances in Materials and Processing Technologies

Characterisation of friction stir welds by logistic regression using fractal and wavelet features

This paper presents the three-dimensional numerical simulation of a micropump, including diffuser and analytical modelling of the micropump flow rate. The numerical simulation of the diffuser is performed in all possible flow regimes to optimize its geometry for maximum efficiency. The deflection of the piezoelectric polymer composite circular actuator is analytically solved by theory of bending plates to determine the volumetric change and flow rate. The result is then extended for actuator bonded to diaphragm of the micropump considering it as bilaminar plates. From the simulation results, it is found that and the diffuser angle >30° results in flow recirculation and reduction in the efficiency. The flow rate of the micropump obtained from analytical model and the numerical simulation are found to be similar. © 2018, © 2018 Informa UK Limited, trading as Taylor & Francis Group.

Electronics

School of Electronics Engineering

International Journal of Modelling and Simulation

A design analysis of piezoelectric-polymer composite-based valveless micropump

Valveless micropumps are extensively used in micro fluidic systems, including health care monitoring and diagnostic devices, computer devices, and so on, as it forms the critical component in the microsystem for precise and controlled fluid handling. This paper proposes the design and development of a novel, significantly low cost, planar micropump with piezoelectric polymer composite, consisting of lead zirconate titanate and polyvinylidene fluoride, for actuation. The novelty lies in the synthesis and use of the piezoelectric polymer composite as the actuating mechanism and the diffuser/nozzle design around the line of appreciable stall to achieve maximum flow rate for the given boundary conditions. The parametric study on the micropump geometry, including, chamber depth and diameter as well as diffuser/nozzle was carried out by using numerical simulations in COMSOL multiphysics, to analyze the fluid flow rate. The response of piezoelectric polymer to the applied sinusoidal voltage causes flow rectification in the micropump. An aspect ratio (diffuser length/diffuser width) of 15 produces maximum fluid flow rate. The designed micropump can achieve maximum fluid flow rate at low applied voltage and frequency of operation. [2018-0166] © 1992-2012 IEEE.

Journal of Microelectromechanical Systems

Design and Development of Piezoelectric Composite-Based Micropump

During sheet metal formation, the high strength of sheet material leads to high contact stress between the die and blank material, which results in increased die wear. Moreover, the reduction in the use of lubricants because of environmental concerns has led to greater wear of sheet metal-forming dies. It is important to understand the tribological behavior of the blank die contact so that steps can be taken to reduce the die wear to an acceptable level. Die wear reduction is possible by using alternative die materials, modifying die geometry, or by creating a wearresistant surface on sheet metal-forming dies using Physical Vapor Deposition (PVD) coatings. PVD coatings have a thickness in the micro range and greatly improve the tribological properties of the die material. In this work, three pins made of AISI D2 steel were coated with Titanium Nitride, Titanium Aluminum Nitride (TiAlN), and Aluminum Chromium Nitride using the PVD process. Friction and wear tests were conducted on the pin-on-disk testing machine as per ASTM G99, Standard Test Method for Wear Testing with a Pin-on-Disk Apparatus. The pins had diameters measuring 10 mm and lengths measuring 35 mm. They were heat treated until they reached 55 HRC and ground to a Ra value of 0.1 μm. A 5-mm-radius tip was provided on one end of the pin. D3 steel was used as counter material (disk). The normal load was 30 N, and the sliding speed was 0.3 m/s. The experiments were conducted in dry contact conditions. Based on the results, it was concluded that TiAlN coatings are an excellent choice to modify friction behavior and improve wear resistance of die material. Copyright © 2018 by ASTM International.

Vellore Campus

Materials Performance and Characterization

Improvement of Tribology in Sheet Metal Forming of High-Strength Steel Sheets by PVD-Coated Dies

Light weight and high strength steel has been used as a substitute for conventional steel in sheet metal forming operations. High strength steel is less formable than conventional steel. A thorough understanding of the factors limiting the formability of high strength steel is important from engineering as well as economic viewpoint. In this work three different materials, galvanic coated steel, EN42J steel and stainless steel (Grade 304) are taken for analysis. The influence of blank holding force on the formation of cups is investigated. The springback behavior of high strength steel sheet is investigated by conducting split ring tests. © 2018 Praise Worthy Prize S.r.l. - All rights reserved.

International Review of Mechanical Engineering (IREME)

Experimental Investigation of Springback in Forming of High Strength Steel Using Split-Ring Test

VIT Unitversity

Department of Information Security

School of Computer Science and Engineering

Friction stir welding parameters optimization for tailored welded blank sheets of AA1100 with AA6061 dissimilar alloy using response surface methodology

Micro-electromechanical systems are electrically sensed and actuated mechanical devices that are in micrometre-sized overall dimensions. The microsize of the system enables it to be used in several critical applications including healthcare where the system performance can be precisely controlled. One such application is micropump for drug delivery. Micropumps can be either valve based or valveless. Valve-based micropumps have mechanical check valves to control and deliver drugs through flaps or membranes. In valveless micropumps, the control is made through a diffuser/nozzle arrangement which regulates the liquid flow rate. In this paper, a valveless insulin pump based on piezoelectric actuation made of polymer-based material as diaphragm in planar type is constructed and the dependency of flow rate with material properties and size is studied. The modelling of the pump is carried out using COMSOL Multiphysics by coupling fluid structure interaction (fsi) and piezoelectric (pzd) physics module. The transient response of the flow rate and pressure distribution was studied. The dependency of flow rate with applied voltage, frequency and aspect ratio of the diffuser/nozzle was characterised by various size of the piezo layer and diaphragm layer. The effect on flow rate with polymethylmethacrylate and polydimethylsiloxane with single layer and stacked double layer was characterised. Sinusoidal actuating voltage is applied on piezoelectric material and varied up to a maximum of 180 V, 100 Hz. The simulation result proved that the flow rate can be effectively controlled with the application of appropriate combination of external sinusoid voltage, frequency and aspect ratio of the diffuser/nozzle. © 2016, © 2016 Informa UK Limited, trading as Taylor & Francis Group.

Study of the effect on flow rate for planar type polymer-based diaphragm piezoelectric actuated valveless micropump for insulin delivery

Tool steel is extensively used in metal cutting and forming operations. Its surface properties such as wear resistance and hardness can be improved by various surface modification methods. Conventional thermo chemical surface modification methods like carburizing, nitriding and boroding will not be able to provide the intensive energy source necessary to modify surface structure without disturbing microstructure and properties of core. One of the promising methods to improve wear resistance is thermal evaporation of Molybdenum disulphide (MoS2) powder on tool steel substrates. The metallographic study and chemical composition analysis of thermally evaporated MoS2 coated thin films were conducted using scanning electron microscope integrated with energy dispersive x-ray spectroscopy. The samples were observed using the scanning electron microscope while the EDX detector was used to collect composition data from the sample. The adhesion of thin film with substrate is evaluated by conducting a film substrate adherence test. A low friction, wear resistant and well adherent thin film of molybdenum disulphide is successfully deposited on tool steel substrates by thermal evaporation technique and characterized. © 2016 Elsevier Ltd.

Fulltext

Materials Today: Proceedings

Characterization of thermally evaporated MoS2 thin film coatings

In metal cutting industries cutting fluids are widely used to obtain longer tool life and better surface finish of the component. In metal forming industries oil based lubricants are used to control friction, reduce die wear and thereby increase the surface quality of the component. The cutting fluids and lubricants used in metal cutting and forming industries represent 16-20 % of the manufacturing costs and have several negative health and environmental impact. Green or dry machining is desirable for a clean, safe and cost effective process with high quality products. In this paper, the performance evaluation of poly crystalline cubic boron nitride cutting tool towards the goal of dry machining is presented. © 2014 The Authors.

Procedia Engineering

Green Machining and Forming by the use of Surface coated tools

Science and Technology of Welding and Joining

Influence of weld geometry and mismatch on formability of aluminium tailor welded blanks: numerical and experimental analysis

2010 Second International Conference on Communication Software and Networks

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