Department of Mechanical Engineering

Indian Institute of Technology Palakkad&nbsp;(IIT Palakkad or IIT PKD) is a public autonomous&nbsp;engineering&nbsp;and&nbsp;research&nbsp;institute located in&nbsp;Palakkad,&nbsp;Kerala. It was&nbsp;one of the five new&nbsp;IITs&nbsp;proposed in the&nbsp;2014 Union budget of India. The campus was inaugurated on 3 August 2015. The institute has 94 faculty, 978 students, and 63 non-teaching staffs.

IT Palakkad currently offers four-year Bachelor of Technology (B.Tech) and two years MS programmes in 8 different engineering disciplines including&nbsp;Computer Science, Electrical, Mechanical, Civil among others.

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IIT Palakkad

India-UK SPARC Webinar on Metal Additive Manufacturing and Friction Stir Processing: Present and Future

The curvature-sensitive localisation of proteins on membranes is vital for many cell biological processes. Coarse-grained models are routinely employed to study the curvature-sensing phenomena and membrane morphology at the length scale of a few micrometres. Two prevalent phenomenological models exist for modelling the experimental observations of curvature sensing: (1) the spontaneous curvature (SC) model and (2) the curvature mismatch (CM) model, which differ in their treatment of the change in elastic energy due to the binding of proteins on the membrane. In this work, the prediction of sensing and generation behaviour by these two models are investigated using analytical calculations as well as dynamic triangulation Monte Carlo simulations of quasispherical vesicles. While the SC model yields a monotonically decreasing sensing curve as a function of the vesicle radius, the CM model results in a non-monotonic sensing curve. We highlight the main differences in the interpretation of the protein-related parameters in the two models. We further propose that the SC model is appropriate for modelling peripheral proteins employing the hydrophobic insertion mechanism, with minimal modification of membrane rigidity, while the CM model is appropriate for modelling curvature generation using scaffolding mechanism where there is significant stiffening of the membrane due to protein binding. © 2020, Indian Academy of Sciences.

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Pramana - Journal of Physics

Models for membrane curvature sensing of curvature generating proteins

Micro grinding is an emerging technology for producing structured surfaces on hard and brittle materials. A micro pencil grinding tool (MPGT) consists of a layer of superabrasive grits, bonded to a solid cylindrical surface. Randomly distributed and geometrically undefined grits interact with the workpiece surface at random positions. These random grit positions and protrusions lead to a difference in the size of undeformed chips. This study presents an analytical method to understand the undeformed chip geometry, that considers grit kinematics. Kinematic simulation of grit trajectory paths in longitudinal direction showed a reduced number of active grits in micro grinding with an increase in speed ratio and with reduced tool dimensions. MPGTs with different diameters, grit sizes, and planar grit densities have been used to perform the experiments on a 16MnCr5 hardened steel material. The influence of maximum radial height grits on surface generation in micro grinding has been verified experimentally for up and down grinding modes. Microscopic observations of ground surfaces have shown the distinct differences between up and down grinding modes, which are similar to the surface generation in milling processes. Moreover, the formation of linear grooves with uniform depth and width unlike conventional surface grinding at lower speed ratios indicated the influence of individual grits on surface generation. Trajectory path simulation results have also shown the same observation. © 2019 Elsevier Ltd

International Journal of Machine Tools and Manufacture

Analytical and experimental investigations on the mechanisms of surface generation in micro grinding

This work reports the characterization of AA6061/SiC/FA hybrid composites joined using friction stir welding (FSW). FSW was conducted by employing various tool pin profiles such as straight cylindrical (SC), tapered conical, straight square (SS) and cylindrical threaded. Microstructure and mechanical characteristics of joints were investigated using these tool pin profiles. Microstructure study of the weld joints was carried out through scanning electron microscopy and electron backscattered diffraction (EBSD) analysis. The results show equiaxed distribution of grains in the nugget zone. EBSD analysis indicates that the average grain size reduces to 3 µm after FSW with the presence of high-angle grain boundaries. Higher joint efficiency (85%) is obtained for joints obtained using SS tool pin compared to their counterparts, and SC tool yields minimum joint efficiency (77%). Overall 8% enhancement of the joint efficiency is achieved using SS tool pin profile. © 2020, The Indian Institute of Metals - IIM.

Transactions of the Indian Institute of Metals

Characterization and Evaluation of Joint Properties of FSWed AA6061/SiC/FA Hybrid AMCs Using Different Tool Pin Profiles

In this work, a detailed investigation on the effects of particle diameter on the fluidization characteristics of gas–particle flows inside a bubbling gas–solid fluidized bed has been carried out. The studies are performed using an in-house flow solver developed employing the Eulerian–Eulerian two-fluid model. Simulations carried out using the solver indicate that particle diameter has significant effects on the overall flow hydrodynamics inside a bubbling gas–solid fluidized bed. Numerical evidence suggests that time-averaged particle velocity at any section inside the fluidization zone decreases, while the time-averaged particle volume fraction increases with an increase in particle diameter. For a given diameter, the magnitude of maximum time-averaged particle velocity at any section has been found to increase gradually inside the fluidization zone as we move toward the outlet. Interestingly, this variation in the time-averaged particle velocity with height becomes less prominent with the increase in particle diameter. © 2019, OWZ.

Computational Particle Mechanics

A computational analysis of the role of particle diameter on the fluidization behavior in a bubbling gas–solid fluidized bed

Physics of Fluids

Comment on "a new approach for the design of hypersonic scramjet inlets" [Phys. Fluids 24, 086103 (2012)]

Wire breakages and spark absence are two typical machining failures that occur during wire electric discharge machining (wire-EDM), if appropriate parameter settings are not maintained. Even after several attempts to optimize the process, machining failures cannot be eliminated completely. An offline classification model is presented herein to predict machining failures. The aim of the current study is to develop a multiclass classification model using an artificial neural network (ANN). The training dataset comprises 81 full factorial experiments with three levels of pulse-on time, pulse-off time, servo voltage and wire feed rate as input parameters. The classes are labeled as normal machining, spark absence and wire breakage. The model accuracy is tested by conducting 20 confirmation experiments and the model is discovered to be 95% accurate in classifying the machining outcomes. The effects of process parameters on the process failures are discussed and analyzed. A microstructural analysis of the machined surface and worn wire surface is conducted. The developed model proved to be an easy and fast solution for verifying and eliminating process failures.

Advances in Manufacturing

Prediction and analysis of process failures by ANN classification during wire-EDM of Inconel 718

The increase of B4C addition into an AA6061-B4C composite system will not be always an ideal choice for improved properties because of the issues related to incorporation, distribution and interfacial wetting while stir-casting. In such a case, ultrasonication is considered to be an alternative to get the advantage of microstructural changes which in turn improve the properties. In the present study individual B4C distribution and the refinement of microstructure was achieved at 4wt.%B4C. The improved specific ultimate and compressive strengths at 4wt.%B4C were observed as 36.32% and 43.92% whereas specific Vicker's and Brinell hardness as 53.41% and 50.89% respectively.2009 Elsevier Ltd. All rights reserved.

Engineering Science and Technology, an International Journal

Enhanced mechanical properties of AA6061-B4C composites developed by a novel ultra-sonic assisted stir casting

Additive manufacturing makes parts with greater speed and gives freedom for designer. LENSTMis an additive manufacturing method which uses three dimensional CAD model designed by CAD software for depositing metal products directly from metal powder. The effect of process parameters for wear resistance, corrosion resistance for LENSTMdeposited components and the values are compared with wrought alloy. The optimized Values of corrosion and wear resistance are superior to wrought SS 316L alloy. © 2020 Elsevier Ltd. All rights reserved.

Materials Today: Proceedings

Comparison of wear and corrosion resistance behaviour of LENS TMdeposited SS 316L alloy and wrought alloy

Friction hydro-pillar processing (FHPP) is a novel technique that involves solid-state joining of an external plug onto a substrate by plastic deformation. A systematic investigation on material flow during FHPP is required but rarely reported. The present work reports a coupled theoretical and a three-dimensional X-ray computer tomography-based experimental study using a Ti-alloy as a tracer material to realise the material flow during FHPP of a AISI 4140 steel substrate. The cumulative results showed that the central portion of the plug deformed in a series of layer-wise shear planes. However, the plasticised material towards the outer area of the plug flowed through the clearance between the plug and the substrate with excess volume moving out as flash. © 2019, © 2019 Institute of Materials, Minerals and Mining. Published by Taylor & Francis on behalf of the Institute.