Department of Mechanical engineering

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Author: search.filters.author.Mathew, Nitin TomSubject: search.filters.subject.Mechanical Engineering

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    Sustainable Techniques for Machining Difficult to Cut Materials
    (NOVA, 2020-09) Mathew, Nitin Tom
    For many years machining is playing a vital role in the global economy. It is a proven fact that a tremendous amount of heat energy developed during machining. The majority of the heat energy generated during the machining disperses with the help of cutting fluids, which poses numerous challenges to the environment and humanity. Presently, the primary focus of the manufacturing industries is cost reduction without compromising product quality, along with the implementation of sustainability. With the advancement of new difficult to machine materials like superalloys, titanium aluminides, and other hardened ferrous metals in the manufacturing industries, there was a need to identify alternative cooling and lubrication techniques to machine them sustainably. These materials have numerous applications in industries such as aerospace, automobile, and power production due to their excellent physical properties. The heat energy developed during the machining of these materials is higher compared to other materials and requires an effective cooling system to remove the generated heat. The use of cutting fluids for machining has numerous benefits, but they often pose a hazard to man, machine, and material. To curb these issues and other critical issues such as a rise in consumption of natural resources, concerns due to increasing population, limited natural resources, globalization, etc. there is a necessity to switch on to sustainable manufacturing. In almost all the fields of engineering, the concern about the environment is gaining importance. Researchers have developed various techniques to compact the increased use of cutting fluids. The foremost sustainable methods for cleaner production can be categorized majorly into cutting tool processing and cooling and lubrication strategies. The combination of both techniques can bring more advantages to machine these materials sustainably. The chapter discusses various sustainable techniques to machine difficult to machine materials along with the combination of these techniques, which can be most efficient in machining these materials.
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    Dry Deep Drilling of Titanium Aluminide
    (ASME, 2016-03) Mathew, Nitin Tom
    Intermetallic titanium aluminides are recognized as the possibly alloys for high performance aerospace and automobile application. There is an increasing interest of this material due to their extraordinary material properties. The understanding of the machinability of titanium aluminides during various metal cutting processes is very much essential for its wide acceptance over various fields of application. Drilling, with high aspect ratio is a key machining area to be explored because of its complex nature. In the present work, holes were drilled on a titanium aluminide intermetallic alloy with an aspect ratio of 9.37, focusing on the machinability under dry environment using coated and uncoated twist drill. Machinability investigations were evaluated based on the, thrust force, torque, surface integrity, chip morphology, burr formation and performance of the tool. From the results of thrust force and torque, it is revealed that the coated tool doesn’t show any significant advantages over the uncoated tool. The variation of chip shapes was observed as the depth progresses. Small ring shape, uniform and non-uniform roll back burr were observed as the cutting parameters are varied. The adherence of workpiece material on to the tool and various surface defects were observed under all cutting conditions.
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    Fabrication of Ti-6Al-4V thin sheet using wire-EDM and its characterisation
    (Inder Science, 2022-02) Mathew, Nitin Tom
    An appreciable demand for thin titanium sheets is observed in recent years due to technological development in various sectors. The existing sawing methods are uneconomical to produce high aspect ratio sheets with good dimensional accuracy. The current work focuses on extracting thin sheet of 380 mm × 50 mm × 0.2 mm from Ti-6Al-4V using wire electric discharge machining and investigated the dimensional and surface variations. The preliminary study using usual wire EDM procedure resulted in poor dimensional accuracy for a thickness in the range of 500 µm due to the lateral movement of sheet free end. Hence, in this work, a support system is attached to workpiece to minimise sheet movement and to improve the flushing during extraction. This helped to reduce the thickness variation up to 6% for a 0.2 mm Ti-6Al-4V sheet. The root mean square roughness is found to be consistent up to a height of 240 mm from the top surface. Also, majority of the measured skewness are positive. Altogether, the results of the study can be applied to fabricate thin sheets for additive manufacturing process.
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    The potential of microfluidic devices in dermatology
    (Wiley, 2021-10) Mathew, Nitin Tom
    The potential of microfluidic devices in dermatology. - Abstract - Europe PMC Sign in | Create an account https://orcid.org Europe PMC Menu About Tools Developers Help Contact us Helpdesk Feedback Twitter Blog Tech blog Developer Forum Europe PMC plus Search life-sciences literature (42,135,236 articles, preprints and more) Search Advanced search Feedback This website requires cookies, and the limited processing of your personal data in order to function. By using the site you are agreeing to this as outlined in our privacy notice and cookie policy. Abstract Full text The potential of microfluidic devices in dermatology. Mathew NT 1 , Mathachan SR 2 Author information Affiliations 1 author 1. Mechanical Engineering, Work Integrated Learning Programmes Division, BITS Pilani, Pilani, India. 1 author 2. Department of Dermatology, Venereology and Leprosy, Atal Bihari Vajpayee Institute of Medical Sciences
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    Application and future prospects of additive manufacturing in dermatology
    (OUP, 2022-06) Mathew, Nitin Tom
    The article discusses the additive manufacturing/3D printing of human skin for advanced applications. Even though this is still in its infancy, additive manufacturing has the potential to revolutionize the field of dermatology and cosmetology.
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    Low-Cost Automation Mechanism for Rotor Press Machine
    (Springer, 2022-10) Mathew, Nitin Tom
    Pressing rotors on a high-pressure press are an important stage in the manufacturing of rotors for ceiling fans and other appliances. This pressing is done mainly to eliminate bending or distortion defects formed on its surface due to the aluminum die casting process taken place before. Due to this distortion or bending defects, rotors get rejected during their assembly. The available facility at the organization for this purpose was not very efficient and was causing a lot of production as well as financial loss to the organization. For this purpose, it was proposed to conceptualize, design, and develop a low-cost automation mechanism, which would eliminate this problem. The main task in hand was to make sure the entire diameter of the rotors gets pressed properly in one single stroke of the press machine. For this purpose, design changes in the layout of the machine were done. By using this project, the organization was able to improve its production efficiency, and human intervention in manufacturing activities was reduced to a minimum.
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    Fabrication of microchannels for microfluidic devices using laser micromachining
    (Elsevier, 2023-08) Mathew, Nitin Tom
    Micro machining is widely used to create micro features for various applications. Laser micromachining is gaining importance for its flexibility, accuracy, and its ability to process a wide range of materials. The various challenges in CO2 laser micro machining include achieving high surface finish and variable cross-sectional profile of micro channels. In this work, the micro channels machined on polymethyl-methacrylate are studied. The effect of laser machining overlap and repeated machining on the profile of micro channels at constant laser power and machining speed is investigated. The influence of the parameters on the width of the channel and surface quality is studied in this work.
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    Tool condition monitoring in mechanical micromachining
    (CRC Press, 2023) Mathew, Nitin Tom
    Tool condition monitoring using sensors has become an integral part of machine tools to enhance product quality and productivity. The breakage of the tool causes poor surface quality and dimensional accuracy for machined parts, or possible damage to a workpiece or machine. Tool condition monitoring is considerably vital in the manufacturing industry. In this chapter, tool condition monitoring during mechanical micromachining is discussed. In mechanical micromachining the size of the tool significantly scales down and it becomes difficult to monitor the micro tool. During the micromachining process, there can be breakage of tool or tool wear which are challenging to detect with conventional methods due to the micro tool size. The micro tool is subjected to comparatively high cutting force and vibration during the micromachining process as the tool wear increases. To retain precision as well as quality in the components, it is necessary to monitor the condition of the micro tool. Tool condition monitoring supports this situation with the help of various sensors
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    Multi-Objective Optimization of Microturning Process Parameters Using Particle Swarm Technique
    (ASME, 2013-11) Mathew, Nitin Tom
    In this work, for the first time an attempt has been made to carry out multi-objective optimization for tool based microturning process parameters using particle swarm optimization (PSO) technique. The input microturning process parameters considered are speed, feed and depth of cut. The output parameters considered are material removal rate (MRR), surface roughness (Ra) and tool wear (TW). The significant parameters are identified individually using ANOVA and main effect plots. However, it is observed that the main goal of the manufacturers is to produce high quality products in shorter interval of time. In order to meet the above objective, multi-objective optimization is carried out to achieve simultaneously higher MRR, low Ra and low TW using PSO. From the PSO analysis, it is observed that the combination of microturning parameters such as speed (18.25 m/min), feed (9.31 μm/rev) and depth of cut (14.61 μm) results in high MRR, low Ra and low tool wear. The PSO analysis indicates that it is a promising optimization algorithm due to its simplicity, low computational cost and good performance. A confirmation test was carried out to validate the predicted results.
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    Electroplated CBN superabrasive wheel for grinding intermetallic titanium aluminide
    (Inder Science, 2019-02) Mathew, Nitin Tom
    An experimental investigation is reported on the surface grinding of intermetallic gamma titanium aluminide using electroplated cubic boron nitride grinding wheel. In order to implement the wide acceptability of this material in various fields, the machinability investigation finds crucial especially during grinding. In the present work, the machinability of gamma titanium aluminide of two different compositions was investigated by analysing the normal and tangential force, surface integrity, chip morphology and the condition of grinding wheel after the experiments. The minor variation in the composition of titanium aluminide has influence on the generated cutting forces, the knowledge of which is essential for satisfactory use of this material in various applications. The observations from the machined surface have shown the presence of various surface defects and the analysis of chip morphology revealed the occurrence of high temperature during the grinding. The topography of the grinding wheel is also investigated after the experiments.