NUST Institutions Library Catalogue Search for 'au:"Supervisor : Dr. Syed Hussain Imran Jaffery "'

Optimization of parameters for drilling of hard rocks in petroleum exploration a project thesis

By Shahid Sadiq. Islamabad SMME NUST 2013 . 90 p.

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Investigation of Turning Parameter of Machining Inconel 718 /

By Siddique, M. Zeeshan . . 72p. 30cm.

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Laser-based Ultrasonic Assisted Low Speed Micro Milling of Super Alloys /

By Haidary, Yadullah . . 65p. 30cm.

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Topology Optimization of High-Power Electronics Enclosures using Generative Design & Additive Manufacturing /

By Jamil, Atif . . 63p. 30cm.

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Numerical and Experimental Characterization of Melt Pool in Selective Laser Melting of Ss316l /

By Khan, Ahsan . . 98p. , The additive manufacturing technology Selective laser melting (SLM) also referred as laser powder bed fusion (LPBF) is a technique that can produce intricate metallic parts in 3D. However, maintaining an accurate surface finish and shape can be difficult because of the dynamic thermal cycles of melting and solidification. To produce high-quality products, it is essential to maintain the dynamic stability of melt pool in SLM. This requires studying the temperature distribution and thermal behaviour within the pool. In this study, a Finite Element Modelling (FEM) approach that was experimentally verified was utilized to precisely ascertain the thermal profiles and dimensions of the molten pool. To investigate the impact of different process variables on the shape of the pool during the selective laser melting (SLM) of SS316L powder, a transient model was employed. A FEM model was proposed to evaluate the temperature gradient and characteristics of the molten pool during SLM, with laser penetration depth also taken into account. The proposed heat source model was calibrated with data from the literature. The FEM model was subsequently adjusted and validated through further experimentation to ensure that it accurately predicts the melt pool dimensions and temperature profiles. The model findings were consistent with the experimental data, and the effects of interlayer and intertrack were examined. For each layer and track, the molten pool depth, width, and length of the and the temperature distribution were assessed, and the findings were analyzed for each variable. The FEM model had relative errors of 1.88%, 1.49%, and 2.12% for the predicted melt pool length, width, and depth, respectively, compared to the experimental measurements, for a range of optimal parameters. 30cm.

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Process Optimization by Multiscale Modeling to Minimize Residual Stress in Powder Bed Fusion /

By Dilawar, Shakeel . . 134p. , Metal additive manufacturing often uses powder bed fusion (PBF), a renowned technology that selectively fuses metal powder particles in a bed using a laser or electron beam to create threedimensional objects. The metal powder exposed to the laser undergoes enormous temperature and phase change variations in a short period of time during PBF, resulting in undesired thermal stresses known as residual stresses. To quantify these stresses, the bridge curvature method (BCM) was applied. Multiscale modelling using adaptive coarsening was used to predict distortions based on experimentally validated models. Taguchi and Response Surface Method (TM and RSM) were used to minimize residual stress in stainless steel 316L. Based on optimal parametric results for minimal residual stress from part-scale simulation and statistical techniques, the parts were printed avoiding costly experiments. There was a minimum 8% error between optimized predicted and experimental results. The approach used was critical in lowering computational printing expense. The effects of individual parameters and their combinations in terms of energy density on residual stress were also analyzed. The relationship between residual stress, hatch spacing, scanning speed, and power in metal additive manufacturing can be characterized by an initial increase in residual stress, followed by a decrease as hatch spacing and scanning speed are increased, while power is also increased. The effect of beam diameter is very nominal and diminishes in comparison with energy density parameters. 30cm.

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Micromachining of Inconel 600 /

By Iqbal, Wajid . . 76p. , Today, various industries has increased their demand of miniature components as time advances. As a result it opens a gateway for researcher towards micromanufacturing in the field of aerospace, nuclear, telecom and biomedical sector. Nickle-based alloys possess high tensile strength, strong corrosionresistance and low thermal conductivity having sufficient use in a wide range of temperature application. These alloys are considered as difficult-to-machine material for their low machinability rating. In this research Inconel 600 was selected as workpiece material. Micromachining were performed upto 20 mm length with different combination of machining parameters like feed/tooth, cutting speed, depth of cut, and cooling conditions using orthogonal L9 array. Two-flute, un-coated Tungsten carbide cutter of 0.5 mm diameter were used in experiment. Results were analyzed through analysis of variance to see influence of these parameters on burr generation, tool flank wear, and surface roughness. Results shows that small DOC, high feed rate and high cutting velocity at dry condition results small burr formation with compromise on surface quality and tool wear. Similarly small DOC, low feed rate and high cutting velocity at MQL condition results low surface roughness with compromise on burr formation. Minimum tool wear was observed at low (cutting velocity, feed rate, and DOC) using MQL as cooling method. Optimum parameters has been established using response optimization to get output response as minimum. In future, same procedure can be adopted to replace uncoated tool with coated tool and observe it effect on output response. 30cm.

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Experimenation and Analysis of Tube Spinning using High alloy Steel /

By Subhan, Muhammad Moiz. . 45p. ; 30cm..

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Design and analysis of Skateboard Platform for Electric Vehicle /

By Arshad, Hafiza Fatima . . 63p. , To improve the structural integrity, functionality, and safety of the skateboard platform for electric vehicles (EVs), this study conducts a thorough investigation of its design and finite element analysis (FEA). The increasing need for environmentally friendly transportation options, with EVs leading the way in this shift, is the driving force for this study. The skateboard platform is a unique approach to electric vehicle design that has the potential to completely transform vehicle architecture by providing increased economy, scalability, and flexibility. This study carefully considers a number of design requirements, such as front-wheel drive integration for improved handling and acceleration, suspension setups, and chassis dimensions. Furthermore, in keeping with the objective, the choice of lithium-ion batteries for the energy storage solution takes advantage of their greater energy density and lighter weight. SolidWorks, a well-known CAD program, was used throughout the design process to enable accurate modelling of the skateboard platform and its parts. The platform's unique honeycomb construction, which minimizes weight while maximizing strength and longevity, was inspired by the efficient hexagonal patterns found in nature. By lowering the total mass, this creative design strategy improves the platform's structural stiffness while simultaneously increasing its energy efficiency. The study used extensive FEA simulations using ANSYS software to assess the skateboard platform's structural performance and safety. The platform's resilience was evaluated under two main scenarios using these simulations: static structural loads and torsional forces. Important variables like total deformation, equivalent elastic strain, equivalent stress, and bending stress were the focus of the static structural study. The analysis's conclusions showed how resilient the platform was, with stress and deformation levels staying within secure operating bounds. Torsion stiffness study was also performed to determine the platform's resistance to twisting forces, which is an important factor to keep in mind when navigating uneven terrain and maneuvering vehicles. The analysis produced encouraging findings, showing that the platform could sustain torsional forces with sufficient safety margins. This study component highlights the platform's ability to provide the best possible performance and safety in real-world driving situations.xvi The study ends with a prospective viewpoint that offers directions for additional research and development aimed at improving the skateboard platform. Prospective avenues of investigation encompass investigating cutting-edge materials to augment the platform's efficacy and longevity, refining component arrangements for optimal effectiveness, and carrying out practical trials to objectively evaluate the platform's potential. 30cm.

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Refrigeration Load Calculation Of Cold Storage Box Used For Tomato Storage /

By Khan, Muhammad Salman . . 77p , Food loss and waste is a global problem, approximately 40 to 50% of fruits and vegetables are lost annually, exceeding 1.3 billion tons of food globally, with an estimated 750 billion US dollars wasted yearly. Throughout the stages of cultivation, handling, postharvest, storing, processing, distribution, and consumption, food is lost. A smart cold storage and reefer container is a sophisticated thermal and relative humidity control system designed to preserve and effectively use perishable food products. Due to no proper postharvest and transportation management, we are not losing the quantity, but we are also affected by losing nutritional quality of vegetables and fruits. The present study focused on reducing post-harvest loss of fruits and vegetables, more specifically on tomatoes during storing and transportation by providing an energy efficient small size solar powered smart cold storage solution with real time remote control of temperature and relative humidity. Solar panels are installed on the roof and walls of cold storage boxes for power generation during peak hours and batteries are installed for backup during low solar hours. The cooling is achieved by Vapor compression cycle. The temperature and percent relative humidity are set by a mobile app and are controlled by microcontroller. The cold storage box can be placed in ambient and can also be fixed in a vehicle for transportation as reefer container. The cold storage box includes both hardware and software parts, this IoT based control system is tested on a 110 liters DC chest freezer. The modeling of the temperature and relative humidity distribution inside cold storage walls was done using computational fluid dynamics (CFD). 30cm.

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Investigation of Burr formation and Surface roughness in Micro milling of Inconel 718 alloy /

By Sheheryar, Muhammad . . 47p. , Industry, particularly aviation, has seen remarkable technological advancement in recent years. More micro-scale manufacturing capabilities, notably micro-milling capabilities, are required for high precision machined microparts with complex features in order to obtain the necessary yet exact dimensional accuracy and surface finish. In this study, the influence of feed rate, cutting velocity, depth of cut, and four various types of tools with (AlTiN-, TiSiN-, nACo-coatings, and uncoated) on burr formation, tool wear and surface roughness during micromachining of Inconel 718 was investigated using digital microscope and statistical techniques. On a CNC milling machine, machining experiments were carried out at high speed with a feed rate below the cuttingedge radius for a 10 mm cutting length with a carbide tool of 0.5 mm diameter. The depth of cut was shown to be the most important element in burr creation, whereas cutting velocity was found to be the most important component in surface roughness. Due to the difference in coefficient of friction, cutting tool coating had no effect on either surface roughness or burr development. The depth of cut and feed rate influenced the kinds of burr generated during micro-milling of Inconel 718 while cutting velocity had no effect. It was also determined that the surface finish achieved by high-speed machining is equal to that achieved by transition and low-speed machining and that the burr width discovered during high-speed machining confirmation trials was likewise within an acceptable range. 30cm.

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Evaluation of different metal cutting models during machining of Inconel-718 /

By Hamza, M Ghazi . . 42p. , Inconel-718 is a nickel-based aerospace alloy that has large domain of applications in the aerospace industry and also in ground-based turbines. Machining of Inconel-718 is a very difficult process as it is able to retain its strength even at high temperatures resulting in a lot of tool wear and making it difficult to machine, thus making it a topic of interest among researchers. In order to study the orthogonal machining process of this material, development of a FEM model, in Abaqus software, which can simulate the process with good accuracy is extremely important. To simulate the plastic deformation and damage of Inconel-718, during the machining process, different material modelling techniques are available in the literature. Among these material models, Johnson Cook Plasticity model is widely accepted as being more accurate. When modelling the machining process using FEM, the Johnson Cook Plasticity model is utilized to forecast the plastic deformation and behaviour of a material. However, there are different values of parameters, involved in the JC model equation, available in the literature which have been derived experimentally. Using these different values of parameters in the simulation process of machining brings a variation in the output values. Thus, the need to evaluate these different models arises. This research will focus on identifying which model proves to be more accurate in predicting the cutting forces during machining of Inconel-718. Results obtained from each model will be compared to the experimental results and a conclusion will be derived about which model is preferrable to be used in simulation this process in future. 30cm.

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Design and Fabrication of Solar Electric Vehicle

By Amir Shah, Syed . . 46p. , This thesis presents a comprehensive exploration into the design, fabrication, and realworld implementation of a solar electric vehicle (SEV) featuring a ladder frame chassis. Motivated by the increasing demand for environmentally sustainable transportation solutions, this study aims to revolutionize vehicle architecture by prioritizing economy, scalability, and adaptability. Beginning with meticulous design selections and CAD modeling, the ladder frame chassis was crafted to optimize structural integrity while minimizing weight. Inspired by nature's efficiency, the design strategy sought to strike a balance between weight reduction and robustness, facilitated by SolidWorks software. Subsequent finite element analysis (FEA) simulations using ANSYS software validated the chassis's structural performance and safety under static structural loads and torsional forces. Crucial parameters such as total deformation and stress distributions were scrutinized, affirming the chassis's resilience under diverse loading conditions. The culmination of this research involved the fabrication of the SEV and its successful road testing, underscoring the practical viability of the design. By translating theoretical concepts into tangible results, this thesis demonstrates the efficacy of the ladder frame chassis in real-world driving scenarios, affirming its potential to enhance both performance and safety. The study concludes with forward-looking perspectives, suggesting avenues for further refinement and optimization. Continued research into advanced materials, component arrangements, and performance evaluations promises to further enhance the SEV's efficiency and applicability in sustainable transportation systems 30cm.

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EFFECT OF WIND DEFLECTOR ON LEADING FIN OF SAVONIUS WIND TURBINE: EXPERIMENTAL ANALYSIS /

By Khan, Usman . . 53p. , In the emerging field of energy conversion technology, one of the equipment that have played a major role in the past is steam engines. These technologies, including the steam engine, are utilized to transform fossil fuels (mechanical energy) into usable energy. As wind energy is becoming a vital source of electrical energy globally, wind power plants with high capacity are being constructed all over the world. Despite advancements, the existing technical design is not yet suitable to produce reliable wind energy converters for low wind speeds and urban settings. Savonius Wind turbine is a promising solution to this problem but the problem with the Savonius Wind turbine is that it has a low coefficient of power because of the generation of negative torque. This research aims to manufacture a Savonius Wind Turbine with optimal parameters from previous research. Along with this, this study mainly focuses on installing a deflector to reduce negative torque effect due to the lagging blade of the turbine. A considerable improvement in the performance of wind turbine can be achieved, particularly the coefficient of power can increase up to 35%. 30cm.

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Chip Formation Analysis and Machining Optimization of Titanium Ti6Al4V /

By Sajjad, Muhammad Uzair. . 75p. , The advancement in the materials science domain has led to the development of many robust composite alloys yielding high tensile strength, low density, and good corrosion resistance. One of such materials is the Titanium-Aluminum-Vanadium Alloy TI6Al4V. The addition of Aluminum and Vanadium compounds enhances the overall material hardness in the alloy matrix, thus improving its physical and mechanical properties. During Orthogonal cutting, the flow stress distribution, cutting forces, and surface finish of the working material play a vital role in predicting the material response via utilizing the Finite Element Analysis (FEA) methodology coupled with the Arbitrary Eulerian-Lagrangian (ALE) meshing during simulations performed in ABAQUS platform in orthogonal cutting analysis. The Johnson-Cook (J-C) model is utilized in finite element analysis of metal cutting as it can efficiently model considerations for temperature-dependent visco-plasticity, higher material strain rates, and larger von mises stresses, while incorporating key features including strain hardening of material, strain rate sensitivity, and heat softening. Our Research aims to formulate a Numerical Finite Element Analysis (FEA) based Model which incorporates a wider range of Johnson-Cook (JC) model test sets totaling to 32 simulated sets of JC Parameters (A, B, C, m, and n) in order to identify the optimum JC test set which would allow us to confirm the model characteristics including Cutting Force, Chip Morphology and Surface Finish, Feed Force/Reaction Force, and Von Mises Stress Distribution during the orthogonal cutting of the Ti6Al4V material. Furthermore, the analysis will provide insights into optimizing machining parameters to enhance productivity, minimize tool wear, and improve surface quality in Ti6Al4V machining operations. 30cm.

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Analysis of Specific Cutting Energy Consumption during Machining of Al 6061-T6 alloy, using the Energy Map Approach /

By Warsi, Salman Sagheer . . 199p. , There is an increased emphasis on energy efficiency of manufacturing processes owing to their negative impact on environment. Machining is one of the most widely used process in the manufacturing industry and accounts for more than 15% value in the globally manufactured products. Electrical energy consumption is considered as the major source of environmental and economic impact of machining processes. A number of studies can be found in literature that model and optimize energy consumption in machining processes. However, most of these studies employ power and energy as response variables that makes them machine tool specific. Therefore a generalized machine tool independent approach needs to be developed for energy consumption analysis in machining processes. This research addresses this problem by utilizing specific cutting energy as a response variable. Specific cutting energy takes into account cutting power and material removal rate and is independent of machine tool. A novel specific cutting energy map approach has been presented in this research. Al 6061-T6 alloy has been used as the workpiece material owing to its extensive application in automotive, aerospace and other high-tech products. The developed energy maps can represent specific cutting energy consumption in the form of different regions (very high, high, moderate, low and very low) against varying cutting condition. The energy map approach has been applied in conventional, transitional and high speed machining ranges. The formation of specific cutting energy regions has been investigated and it has been shown that these regions are strongly related with mechanics of cutting process in terms of: shear angle, chip ratio, chip formation, and contact length. It has been shown that energy saving up to 52% in machining of Al 6061 alloy can be achieved by selecting appropriate cutting parameters from the developed energy maps. The undeformed chip thickness was observed to be the most influential machining parameter affecting specific cutting energy consumption. The developed energy maps also revealed the presence of an avoidance zone associated with high cutting speeds and low undeformed chip thickness. Built-up edge was observed to be responsible for formation of avoidance zone. 30cm.

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Finite Element Simulation and Experimental Investigation of Conventional and High Speed Machining of Al 6061-T6 Alloy /

By Akram , Sohail . . 152p. , Aluminium based alloys are important industrially, owing to their high machinability, corrosion resistance, and strength to weight ratio. These properties make them highly suitable to be used in automotive, aerospace and food processing industries. Due to its high industrial importance, minimal tool wear and superior machining characteristics, Aluminium 6061-T6 alloy has been selected as the workpiece in many research works. Many research studies have been conducted in the past for the experimental and numerical investigation of cutting forces, temperatures, residual stresses and tool wear etc. during machining of Al 6061-T6 alloy. A close agreement was found between experimental and simulated results, however, the available FE models for aluminium based alloys have generally been limited to low and medium cutting speed ranges (i.e. below 1600 m/min). It was observed that the experimental cutting forces were dropped suddenly during High Speed Machining (HSM) condition of Al 6061-T6 alloy. This sudden drop in the experimental cutting forces due to adiabatic heating and reduced coefficient of friction at HSM, was not captured accurately by existing models. An effective predictive model which can numerically investigate the effects on Al 6061-T6 alloy in the high speed machining regime (i.e. above 1600 m/min – 2000 m/min) at the feed rates (f) of 0.1-0.4 mm/rev has previously not been reported in the literature. The current research therefore aimed towards the development and testing of an effective FE model that is capable of simulating the machining of Al 6061-T6 alloy at conventional as well as high speed regime. In the current research work, extensive experimentation and numerical investigations were carried out covering low, medium and high speed/shear rate machining regimes using a dynamic coefficient of friction and thermal softening effect at HSM condition. This approach considerably improved the predicted cutting forces obtained through the existing sets of Johnson-Cook (J-C) material constants. The maximum error of (Fc) were reduced to 19.1% and 23.7% at higher cutting conditions for both existing data sets of material constants, compared to earlier predictions of 36% and 41%, respectively (at higher coefficient of friction and without considering adiabatic heating effect). The current research work adopted a new method for measuring cutting forces using a power meter through specific cutting energy approach, by carrying out extensive experimentation and literature validation, which is more economical than commercially available force dynamometers. Besides, for the first time, low, medium and high speed ranges during machining of Al 6061-T6 alloy were defined accurately during the current research work. Finally, a suitable set of J-C material constants were selected through inverse methodology which was found to be as accurate as existing sets of J-C material constants in LSM and MSM regimes but was also found to be more accurate in the HSM range. Therefore, the set of J-C material constants selected in this research work can be used in a consolidated model for the entire cutting range with accuracy greater than the sets of J-C material constants available prior to this research. 30cm.

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Energy Consumption and Tool Wear Analysis in Machining of Titanium Alloys (Ti6Al4V /

By Younas, Muhammad . . 177p. , Mechanical machining is one of the commonly employed techniques in manufacturing industries, given several other production processes. Due to their high hardness and specific strength at elevated temperatures, machining of titanium alloys is considered very difficult. Considering the machinability challenges of these alloys, tool wear and energy consumption during machining remain the main concern for achieving sustainable machining goals. Since the tool wear is linked to the product quality and cost of machining, therefore, a comprehensive wear map approach based on experimental cutting test is very useful for monitoring the tool life. Whereas energy consumption in a machining process is associated with the machine tool efficiency, cost of energy and carbon footprints, the evaluation of energy consumption using energy maps is therefore very helpful in improving machining performances. Thus, improving the tool life and minimizing energy consumption are the prime contributors in achieving economic and energy-efficient benefits of production. The research presented here first studied the tool wear progression in turning of titanium alloy (Ti6Al4V) and then the effect of progressive tool wear on specific cutting energy was further analyzed for the development of the energy map. Tool Wear and Specific Cutting Energy maps were developed for turning of Ti6Al4V alloy by performing a series of unified cutting tests. The wear map developed plots the wear rate on a feed Vs. cutting speed grid and have identified regions of low, moderate and high tool wear rates. Interestingly, a high wear zone (avoidance region) at the interface of low and moderate tool wear appeared on the wear map. Analogous to the wear map, regions of low, moderate and high energy consumption were also identified on the energy map. The two maps developed thus corresponds to the cutting conditions employed in turning operation highlighting high energy and wear regions that should be avoided during the cutting process. Although wear maps have been presented for a variety of materials including Ti6Al4V alloys, this research work presents a wear map together with energy map for turning Ti6Al4V alloy. The energy map plots the Specific Cutting Energy (SCE) utilized at the tooltip against the cutting condition used in the turning process. The energy map methodology was used for the selection of optimal cutting condition that will minimize the energy consumption of the machine tool. The study of the tool chip contact length and the chip formation analysis is a way to understand the interactions and mechanics of a machining process. The analysis of the tool’s flank surface revealed that the chemical interaction between the tool and workpiece is the main cause for high tool wear and energy consumption as titanium alloys are well known for its severe ix reactiveness at higher cutting temperatures. Since machining of titanium alloys is challenging because of the inherent properties of the material, therefore, this research was focused on the study of energy consumption and tool wear analysis to achieve economic and sustainable goals of production engineering. The energy and wear maps thus developed are also very useful on the shop floor and provide for the choice of cutting conditions to produce parts from Ti6Al4V alloys, together with less damage to cutting tools and efficient use of machine tools. 30cm.

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Investigation into the Machinability of Titanium Alloys under Cryogenic Conditions /

By Khan, Muhammad Ali . . 214p. , Manufacturing has been an important activity throughout the history of human civilization. Manufacturing industries use raw materials and labor to convert natural resources into finished products through the use of technology. The manufacturing sector accounts for around 45% of global energy consumption. Manufacturing processes should therefore be productive as well as sustainable. Machining is a subtractive manufacturing process that removes excess material through the use of a cutting tool in order to give the bulk engineering material a functional geometry. It constitutes about 15% of all manufacturing processes. Machining processes are simple, efficient, versatile and economic for bulk production. These processes represent a major chunk of activities run to design and manufacture parts in various industries. A number of metals, alloys and ceramics are processed through machining. Titanium alloys are generally the preferred choice when it comes to applications where corrosion resistance, high strength to weight ratio and good fatigue properties are required. In addition, titanium based alloys also exhibit biocompatibility. These alloys are extensively used in medical, marine and aerospace industries. On the other hand, their low thermal conductivity and high temperature strength reduce tool life and increases energy consumption during the metal cutting processes. Several research studies have focused on productivity, sustainability and quality aspects of machining of titanium alloys as these are important aspects of manufacturing research. Nevertheless, systematic parametric analysis for machining titanium alloys under various cooling conditions, especially cryogenic conditions presents a research gap. Also, since the available process maps were developed under dry conditions, there is a need for development of tool wear and energy maps, being vital output responses, under cryogenic conditions. This research focuses on investigating the machinability of Ti-6Al-4V alloy over a range of machining parameters under varying cutting environments. Dry, wet and cryogenic conditions were selected as cutting environments for comparative analysis. Different machining input parameters were taken into consideration for analysis of key responses including tool wear, specific cutting energy, surface roughness and material removal rate. Process maps were developed by plotting tool wear rate and specific cutting energy against cutting speed and feed. These maps can be effectively used on the shop floor to select specific machining parameters for ix desired output response. Initially tool wear progression was analyzed under dry and cryogenic conditions which formed the basis for further research. Comparative tool wear analysis was conducted at low, moderate and high tool wear regions. It was observed that cryogenic machining improved tool life owing to its cooling capacity. Next, investigation into the machinability of Ti-6Al-4V was conducted by statistical analysis and multi objective optimization under varying machining conditions. Feed rate, cutting speed and depth of cut were taken as the input parameters under dry, wet and cryogenic conditions. Statistical analysis results identified cutting speed as the key input parameter for tool wear rate and specific cutting energy consumption in terms of contribution ratio. On the other hand, feed had the highest contribution ratio for surface roughness. Multi objective optimization was carried out to optimize the machining output. Each machining run was ranked using grey relational analysis. Analysis of regression model of multi objective function identified feed as the most effective input parameter followed by machining environment. Process maps, developed using cryogenic media, demarcated wear and energy charts into regions of low, moderate and high tool wear and energy zones. A high wear zone found amidst lower zone region was marked as avoidance zone. Tool wear map regions of low, moderate, high and avoidance zone were analyzed by plotting tool chip contact length. As compared with the wear map for turning of titanium alloys under dry conditions, the avoidance zone for this wear map shifted towards high feed region. EDS elemental analysis was also carried out to determine and analyze the wear mechanisms during the machining of Ti-6Al-4V. These maps were also characterized using chip morphology by chip compression ratio and shear angle. These maps can prove to be highly useful in making the manufacturing system productive and sustainable at the same time. 30cm..

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Development and Analysis of Advanced Functional Alloys /

By Haider, Ali /. . 253p. , This work comprises of research on development and analysis of two selected alloys based on economic viewpoint, namely; FeCrCo magnetic alloy and NiCrMo dental casting alloy. The research was initiated for compliance to the United Nations guidelines for the Global Goals. The Sustainable Development Goals (SDGs) are the goals of United Nations for peace and prosperity for the people and the planet. The SDGs are an urgent call for action to end poverty and improve health, economy and education. In order to comply with the SDGs, this project was aimed to attend the three global goals including; i) Goal-3 for Good Health and Well Being, ii) Goal-7 for Affordable and Clean Energy and iii) Goal-9 for Industry, Innovation and Infrastructure. Accordingly this research was carried out on low cost FeCrCo magnetic alloy and NiCrMo dental casting alloy. FeCrCo alloy is the most economical alloy for permanent magnet making as it uses low cost elements; however, magnetic energy product can be produced that is at par with that of Alnico magnets. Similarly, NiCrMo alloy is also a very economical dental casting alloy that possess properties equivalent to that of gold alloys, used for the purpose of dental restorations. Both the alloys are technically very suitable for poor and developing nations for providing economical solutions. Economical processing and production of FeCrCo magnets can contribute to the efficient high speed motors and for affordable and clean energy devices. Also this research conducted on NiCrMo dental casting alloy is a remarkable contribution towards affordable dental health care. FeCrCo is a typical deformable magnetic alloy. In this research, the FeCrCo alloy with low cobalt content (12 wt. %) was developed, processed and analyzed. Effect of minor alloying with silicon was investigated, where enhancement of remanence ratio and improvement in squareness of the MH curve was noted with the double isothermal thermomagnetic processing. Taguchi design approach was utilized for properties optimization. Signal-to-noise ratio mean plots demonstrated that best magnetic characteristics, maximum energy product (BHmax) up to 3.89 MGOe, achieved in samples that were forged, thermomagnetically processed and thermally aged for 24 hour treatment cycle. NiCrMo alloy being an economical alloy is popular for dental restorations. Currently NiCrMo alloys are in use by dental labs that contain beryllium in its composition, which is carcinogenic in nature. This research work was conducted on manufacturing and development of the NiCrMo dental casting alloy with minor additions of titanium, cerium and boron to enhance strength, corrosion and tribological characteristics and to decrease the melting temperature for ease of fabrication. Novelty is that the addition of 0.2 percent Boron with 0.4 percent cerium in the base NiCrMo dental casting alloy is found with outstanding combination of characteristics, well suited for dental restorations. The alloy developed has economic significance, especially, for poor and developing nations as the NiCrMo alloy can be used as replacement for gold based costly alloys. The work done could also help in avoiding Be-containing NiCrMo alloys and is a contribution to the bulk material sciences. 30cm..

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Investigating the High-Speed Micro – Machinability of Aerospace Alloys /

By Baig, Amjad . . 206p. , Micro technologies including Micro-Machining have become essential part of the various industries of modern era. Micro-machining is contributing to almost all fields of industries like aerospace, automobiles, telecommunication, electronics, and medical sectors etc. Therefore, 3D products in the industry require quality product and dimensional accuracy even at micron level. Micro-milling, the most versatile micro-machining technique, has gained importance in mass production of 3D components. Micro mechanical tools have great potential for economical manufacturing of miniatured products from variety of materials, in micro-milling operations. However, the previous research work shows some critical issues in direct application knowledge of macro machining domain into micro domain with help of simple analysis of parts dimensions. Thus, research work focuses on areas which require scientific knowledge to be developed for further implementation at micro scale level to improve the quality of final product. Mechanical micro-milling of aerospace alloys remained focus of many researchers in past because of having excellent mechanical properties, at extreme temperatures, that are suitable for different sectors like aviation, automotive, nuclear, marine, and biomedical applications. These are also considered a better option for applications where stresses need to be minimised. Inconel alloy (Nickel-chromium based) and Monel alloy (Nickel-copper based) being part of aerospace alloy, possesses greater strength and excellent corrosion resistance, work hardening properties at elevated temperature. In aerospace sector, parts like discs, some critical jet engine parts are also being manufactured with these alloys. Nevertheless, Nickle alloys are hard to machine materials and have inherited poor machinability because of low thermal conductivity. Low thermal conductivity results in significant increase of temperature at the cutting zone which results in decreased life of cutting tool. Available research knowledge of vital process parameters (feed per tooth, depth of cut, cutting speed, etc.) in relation to micro-milling of Monel and Inconel alloys at high-speed micro-machining (HSM) under various cooling environments and with multiple micro tool coatings present a research gap. There is need to cover this gap by analysing effects of multiple cutting parameters with wide range on responses at high-speed micro-machining of these alloys. This research focuses on investigation of high-speed micro machinability of aerospace alloys including Inconel 600, Monel 400 under multiple cooling environments and various cutting x conditions. Machining related key input parameters like cutting speed (m/min), feed per tooth (µm/tooth), depth of cut (µm), various micro tool coating (TiAlN, TiSiN and nACo) and multiple cooling conditions (Cryogenic, wet and dry) were taken into considerations for analysis and their effect on responses like tool wear, surface roughness, and burr formations. To have a thorough insight into micro machinability of aerospace alloys, Feed per tooth, was selected above and below the cutting-edge radius of the micro tools. Due consideration was also given to burr formation at up milling side and down milling side. All experiments were categorized into three sets, where first set of experiments were carried out with key process parameters under various cooling conditions (Cryogenic, wet and dry). Second set of experiment was conducted with input parameters using multiple micro tool coatings (TiAlN, TiSiN, nACo) in addition to un-coated micro tool. Third set included validation experiments of all categories. Investigation, into the micro machinability of Inconel and Monel alloys, was carried out through statistical analysis and multi objective optimization (MOO) with various cooling environments and multiple cutting conditions. As process parameters and response parameters are independent and different in nature therefore multi objective optimization was essentially required to optimize the machining output. Grey Rational Analysis (GRA) ranked each experiment. Regression model analysis of multi objective function, identified optimum process parameters in both categories. Outcome of this research work provides in-depth and significant knowledge on utility and importance of making manufacturing system more productive with quality and accuracy required for 3D parts at micro-machining level. Results show that proper selection of tool coatings and cooling environment produce significant improvements in performance compared to conventional tools and cooling environments, in field of micromachining. As a result of ANOVA, ‘Cooling condition’ figured out the most significant factor with contribution ratio (29%) towards surface roughness followed by cutting speed with contribution ratio (26%). It was also influential factor for tool wear with contribution ratio 26%. Feed per tooth figured out as most significant factor for their effect on burr formation in both cases i.e., up, and down milling case for Inconel 600 alloy with contribution ratios, Burr width - down milling case (66%), Burr height- down milling case (44%), Burr width- up milling case (35%). xi Feed per tooth was the most significant factor for its effects on surface roughness including burr formation in both modes i.e., up and down milling side, in micro-milling of Monel 400 alloy using multiple tool coatings, with contribution ratios, Surface roughness (28%), Top Burr width (up and down milling side) 56%, 57%, Top Burr height (up and down milling side) 24%, 28%, respectively. Depth of cut is the most significant factor for tool wear with contribution ratio 34%. nACo coated tool showed least tool wear in micro-milling of Monel 400 alloy whereas uncoated tool showed worst tool wear. Cutting condition, with TiAlN coated tool, has a positive intercept gain of 4%, 8% and 1.03% on uncoated micro tool, TiSiN micro coated tool and nACo micro coated tool conditions, respectively 30cm..

Place Hold on Investigating the High-Speed Micro – Machinability of Aerospace Alloys /