Laser surface texturing is one of the key technologies in micromachining domain for generating defined surface features in micro-components in recent times. In this process, highly focused laser beam is irradiated on the material surface... more
Laser surface texturing is one of the key technologies in micromachining domain for generating defined surface features in micro-components in recent times. In this process, highly focused laser beam is irradiated on the material surface and laser scanning is carried out at different scanning patterns to alter surface conditions for improving the tribological properties of that surface. In this research study, an attempt has been made to carry out laser surface texturing on pure titanium material having a thickness of 1 mm with the aid of a pulsed Nd:YAG laser system. The various process parameters considered for the present research works are laser beam average power, pulse frequency, laser beam scanning speed, and transverse feed. Utilizing response surface methodology, experimentation has been planned. The responses measured are surface roughness, Ra and Rz in lateral and transverse directions and contact angle (θ). The chapter also highlights experimental results for validation of the developed empirical models. The test results have been analyzed using various surface plots. Multi-performance optimization has been conducted to obtain minimum values of surface roughness and contact angle. Using optical microscopic images, influence of process parameters on responses have also been discussed.
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Micro ultrasonic machining is the process for micro hole drilling on hard and brittle materials like ceramic, glass, quartz, silicon, etc. Quartz has wide applications in microelectromechanical systems (MEMS), lenses, pressure and flow... more
Micro ultrasonic machining is the process for micro hole drilling on hard and brittle materials like ceramic, glass, quartz, silicon, etc. Quartz has wide applications in microelectromechanical systems (MEMS), lenses, pressure and flow sensors, and micro-optical systems. In the present research work, optimization of the process parameters for responses such as material removal rate, overcut, and taper angle during micro ultrasonic drilling has been performed utilizing the developed empirical relationship between the responses and process parameters. Three different process parameters— power rating, abrasive slurry concentration, and tool feed rate were considered for this experimental investigation. The parametric studies have also been made based on response surface plot. Based on multi-objective optimization, optimal parametric setting for maximum material removal rate, minimum overcut and minimum taper angle have been obtained.
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One of the newly developed laser micromachining processes for generating micro-turn surface on cylindrical work sample is laser micro-turning process. To explore the capability of this laser micromachining process for achieving particular... more
One of the newly developed laser micromachining processes for generating micro-turn surface on cylindrical work sample is laser micro-turning process. To explore the capability of this laser micromachining process for achieving particular surface profile and dimensional accuracy of machined parts, authors considered a number of experimental investigation to find the effect of process parameters. During investigation and analysis, a number of experimental designs are applied to in-depth analyse the effect of process parameters on surface roughness (Ra and Rz) and depth deviation. The governing equations of spot and circumferential overlap were developed for investigating the effect of these overlaps on surface criteria. By adopting statistical design of experiments approaches such as Response Surface Methodology, the influence of process parameters on process performance were studied. Moreover, novel machining strategy of laser defocusing condition was also implemented for improving ...
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Laser micromachining technology finds great potentials for successful application in the area of high precision micro-engineering. Laser micro-turning process is one of the new and emerging technologies in the area of laser material... more
Laser micromachining technology finds great potentials for successful application in the area of high precision micro-engineering. Laser micro-turning process is one of the new and emerging technologies in the area of laser material processing (LMP) of engineering materials. Laser micro-turning process is one of the latest promising laser material processing techniques which can be employed for generation of micro-turning surface of particular surface profile and dimensional accuracy on cylindrical workpiece. The present paper addresses the laser micro-turning process of cylindrical shaped 99% pure aluminium oxide (Al2O3) ceramics of size 10 mm in diameter and 40 mm in length. The experiments have been conducted utilizing one factor at a time (OFAT) experimental scheme. The targated depth was set at 100 µm. Laser average power, pulse frequency, workpiece rotating speed and Y feed rate were considered as process variables. After each experiment, surface roughness (Ra and Rt) has been...
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Advanced materials are not easy to machine due to technological and industrial development and which discover extensive applications in nuclear engineering, aviation industries, etc. The manufacture of complex shape with high-quality... more
Advanced materials are not easy to machine due to technological and industrial development and which discover extensive applications in nuclear engineering, aviation industries, etc. The manufacture of complex shape with high-quality surface finish and superior accurateness can be easily obtained by nonconventional machining processes. This manuscript covers the significant issues about the performance improvement of ultrasonic micromachining process. This book chapter also focuses on accuracy of ultrasonic micromachining process with process development. The two types of ultrasonic micromachining processes, i.e., stationary USM and rotary USM, are also discussed. Novel development for accuracy on ultrasonic micromachining (USMM) process has been emphasized and discussed. Strategies for development of ultrasonic micromachining system for performance enhancement are discussed for both stationary and rotary ultrasonic micromachining in this chapter. Micro-type tools developments for u...
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Hybrid Machining Processes (HMP) consist of two different types of machining processes which are applied at the same time in the machining zone. These processes are applied for machining of various advanced materials of complex shapes and... more
Hybrid Machining Processes (HMP) consist of two different types of machining processes which are applied at the same time in the machining zone. These processes are applied for machining of various advanced materials of complex shapes and sizes. One of the important HMP is Laser Assisted Jet Electrochemical Machining (LAJECM) where a laser beam of low power and a jet of electrolyte are coaxially focused through a nozzle on a particular machine zone. Thus it eliminates the stray machining effect of ECM process. Machining zone temperature as well as electrolyte current density is increased by laser. Thus electrochemical dissolution rate and MRR are increased. In this process, jet of electrolyte is used as tool which eliminates the complex tool design problem of stand-alone ECM process. Laser assistance in ECM process improves precision, accuracy, surface quality and also productivity. Various researchers have performed their research work on LAJECM. This article focuses on various asp...
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In the present research work, an analysis of fiber laser percussion micro-drilling of quartz is conducted in order to find out the effect of the process parameters on the entry diameter of micro-hole. A response surface methodology-based... more
In the present research work, an analysis of fiber laser percussion micro-drilling of quartz is conducted in order to find out the effect of the process parameters on the entry diameter of micro-hole. A response surface methodology-based experimental design planned and experiments have been conducted for the analysis. The considered process parameters are laser power, pulse frequency, duty cycle, and air pressure. The experimental results reveal that a target value of the micro-hole diameter of 100 µm is generated with the combinations of pulse frequency of 52.05 kHz, duty cycle of 69.47%, laser power of 34.25 W, and air pressure of 1.50 kgf/cm2.
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Electrochemical micromachining (EMM) is widely used for micromachining applications due to its various benefits over other micromachining methods. Microtool is the vital element in EMM, since the features of the microtool like shape, size... more
Electrochemical micromachining (EMM) is widely used for micromachining applications due to its various benefits over other micromachining methods. Microtool is the vital element in EMM, since the features of the microtool like shape, size and surface finish are directly transferred to the work surfaces affecting its machining accuracy and surface quality. Disc shaped microtools are useful to improve the machining accuracy in terms of reduced overcut, taper angle and stray current effects in EMM. Disc microtools fabricated by different machining techniques needs separate machine setup and includes microtool handling, increasing the risk of microtool damage. This paper presents the micro machining techniques to fabricate the disc shaped microtools of different shank diameters, disc diameters and different disc heights with improved surface quality as required for micromachining applications, from tungsten microrod by EMM. Finally, disc shaped microtool of disc �175 µm, disc height 70 ...
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The objective of this article is to exploitrelative machine utilization percentage and machine utilization while designing efficient manufacturing cells in Cellular manufacturing (CM). This production factorsare rarely been utilized... more
The objective of this article is to exploitrelative machine utilization percentage and machine utilization while designing efficient manufacturing cells in Cellular manufacturing (CM). This production factorsare rarely been utilized collectively while designing efficient cells in past CM literature. The proposed model not only minimizes the material handling cost but also maximizes the machine usage in a cell.A novel performance measure termed as Reformed Grouping Efficiency (RGE)is also introduced to verify the goodness of the achieved solutions. The proposed technique can be substantially handy to the production or operational personnel who are believed to decide the appropriate cell configuration on shop-floor.
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Rotary ultrasonic machining (RUM) is an abrasive based advanced machining technique for cutting and finishing of various hard and fragile materials like ceramic, ceramics composite, glass, titanium and its alloy etc. RUM is the... more
Rotary ultrasonic machining (RUM) is an abrasive based advanced machining technique for cutting and finishing of various hard and fragile materials like ceramic, ceramics composite, glass, titanium and its alloy etc. RUM is the development over stationary ultrasonic machining for enhancement of MRR, geometrical accuracy and surface roughness. The basic mechanism of RUM is the combination of ultrasonic machining and conventional diamond grinding. In this chapter development, principle, mechanism, setup details of rotary ultrasonic machining has been discussed. It also highlights the effects of diverse input parameters on performance of RUM. The MRR always increases with spindle speed; tool feed rate and ultrasonic power. The surface roughness improved with spindle speed but worse with tool feed rate and ultrasonic power. The chipping size reduced with spindle speed but increase with tool feed rate and ultrasonic power. The cutting force reduces with spindle speed and ultrasonic power...
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Titanium alloy plays a significant role in the advancement of engineering in the area of advanced structures and technologies for aerospace and power industry, medicine, automatics and mechatronics, and measurement equipment, owing to its... more
Titanium alloy plays a significant role in the advancement of engineering in the area of advanced structures and technologies for aerospace and power industry, medicine, automatics and mechatronics, and measurement equipment, owing to its unique combination of physical, chemical and mechanical such as high strength and stiffness at elevated temperatures , high corrosion resistance, fatigue resistance, high strength to weight ratio and ability to withstand moderately high temperatures without creeping. The conventional cutting methods not only face difficulties for cutting these alloys due to their poor thermal conductivity, low elastic modulus and high chemical affinity at elevated temperatures but also undergo from higher cost associated with the machining of Ti-6Al-4V caused by lower cutting speeds and shorter tool life. The application of micro-grooves on Ti-6Al4V predominantly lies in the biomedical devices and the implantation into the bone which further needs to be integrated ...
In the present days, the requirement of micro-machining has seen a rapid growth for the fabrication of precision machining of complex parts in automobile, shipbuilding, aerospace, electronics, medical industries, etc. Surface finish of... more
In the present days, the requirement of micro-machining has seen a rapid growth for the fabrication of precision machining of complex parts in automobile, shipbuilding, aerospace, electronics, medical industries, etc. Surface finish of these types of components is one of the most important criteria for fabricating better quality and to avoid failure caused by surface defects. The paper addresses the experimental investigation for the variation of surface roughness of micro-channel milling on flat zirconia (ZrO2) ceramics by using a pulsed fiber laser system. In this work, considered parameters are laser power, pulse frequency, laser scan speed, and the number of scan while responses considered are surface roughness parameters, i.e., Ra and Rz. The experimental results show that aforesaid factors revealed huge influences on surface finish criteria on machined micro-channel on zirconia ceramics.
Recently, laser micromachining and micro-fabrication processes have remarkable and diversified applications in the direction to manufacture highly precised and accurate dimensional parts or components which are used in bio as well as... more
Recently, laser micromachining and micro-fabrication processes have remarkable and diversified applications in the direction to manufacture highly precised and accurate dimensional parts or components which are used in bio as well as technological domains such as biomedical, dental and orthopaedic, aircraft engines, micro-electromechanical systems (MEMS), electronic devices, turbocharger rotor parts and nuclear reactors. The present chapter deals with experimental investigation into micro-turning process using pulsed Nd:YAG laser during machining of aluminium oxide ceramics. A number of experimental schemes were adopted to explore the parametric influences on process characteristics such as surface roughness and depth deviation. Experimental investigation was also carried out to improve the dimensional accuracy and surface characteristics of laser micro-turned components using laser defocusing technique.
An attempt has been made to investigate the machinability of zirconia toughened alumina (ZTA) inserts while turning AISI 4340 steel. The insert was prepared by powder metallurgy process route and the machining experiments were performed... more
An attempt has been made to investigate the machinability of zirconia toughened alumina (ZTA) inserts while turning AISI 4340 steel. The insert was prepared by powder metallurgy process route and the machining experiments were performed based on Response Surface Methodology (RSM) design called Central Composite Design (CCD). The mathematical model of flank wear, cutting force and surface roughness have been developed using second order regression analysis. The adequacy of model has been carried out based on Analysis of variance (ANOVA) techniques. It can be concluded that cutting speed and feed rate are the two most influential factor for flank wear and cutting force prediction. For surface roughness determination, the cutting speed & depth of cut both have significant contribution. Key parameters effect on each response has also been presented in graphical contours for choosing the operating parameter preciously. 83% desirability level has been achieved using this optimized conditi...
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Hard and fragile materials for example ceramics, glass and quartz crystals are getting extra consideration in modern years owing to their higher characteristics for example high strength, high hardness, chemical durability and low... more
Hard and fragile materials for example ceramics, glass and quartz crystals are getting extra consideration in modern years owing to their higher characteristics for example high strength, high hardness, chemical durability and low density. Ultrasonic machining is an abrasive based advanced machining with non-chemical, non-electrical and non-thermal process that is particularly suitable for those brittle and hard materials. The USM process principle, mechanism of material removal, varieties of USM set up, tool development of USM process, improvement and production of 3d profile by USM process and various research issues are studied and summarized in this chapter. It also highlights the effects of different parameters of USM process on performance and development of USM process.
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Within the domain of austenitic stainless steel, 316 L stainless steel is widely used in both biomedical and automotive industries due to its superior mechanical properties. In the present research study, the performance of the fiber... more
Within the domain of austenitic stainless steel, 316 L stainless steel is widely used in both biomedical and automotive industries due to its superior mechanical properties. In the present research study, the performance of the fiber laser micro-grooving process with regard to kerf width and surface roughness Ra has been analyzed. The process parameters, i.e., laser power (7.5–20 W), pulse frequency (55–80 kHz), and cutting speed (0.5–3 mm/s) are considered to examine the aforesaid responses. The results of the experiments exhibit that the presence of flowing condition of the high-pressure assist air in combination with varying aforesaid process parameters, have a considerable effect on the kerf width characteristics along with the average surface roughness Ra of microgroove cut on 316 L stainless steel.
Abstract The Inconel 718 has captured global attention for its huge applications in the aerospace and defense field. However, a limited approach is noticed to investigate this material's responses and morphological features after... more
Abstract The Inconel 718 has captured global attention for its huge applications in the aerospace and defense field. However, a limited approach is noticed to investigate this material's responses and morphological features after electrical discharge machining operation. This study wants to offer a more detailed investigating approach, including the analysis of morphological features, recast layer, microhardness, elemental composition, and several textural defects and basic responses. Scanning electron microscopy is used to investigate several textural features, defects, cracks, and recast layers. The findings claim 538 nm–2.168 µm and 14–41 µm variations in crack width and recast thickness, respectively, which increase with pulse current and pulse on-time. However, the low discharge energy can provide better micro-hardness than higher discharge conditions due to having sufficient time for flushing and heat dissipations. The recast surface and the interfaces are, respectively, 7.58%–13.16% and 22.75%–32.74% harder with low discharge condition than the intermediate and higher discharge condition. Moreover, the Energy Dispersive X-ray analysis reported the emigration of 17.81% of carbon and 0.33% of copper from the dielectric and tool during the machining.
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This article on ‘Micro-machining: An Overview (Part II)’ is in continuation to ‘Micro-machining: An Overview (Part I)’ published in this journal ( Journal of Micromanufacturing). It consists of four parts, namely, electrochemical... more
This article on ‘Micro-machining: An Overview (Part II)’ is in continuation to ‘Micro-machining: An Overview (Part I)’ published in this journal ( Journal of Micromanufacturing). It consists of four parts, namely, electrochemical micro-texturing, electrochemical spark micro-machining, molecular dynamics simulation and sustainability issues of micro-machining processes. Electrochemical micro-texturing (ECMTex) deals with various techniques developed for micro-texturing on different types of workpiece-surfaces, namely, flat, curved and free-form surfaces. Here, basically two categories of techniques have been reviewed, namely, with mask and without mask. It also deals with ‘single point tool micro-texturing’ which turns out to be a single-step technique requiring minimum time, but the accuracy and repeatability obtained after micro-texturing need to be critically analysed. For mass production, one needs to go for sinking kind of ECMTex processes. Electrochemical spark micro-machining ...
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ABSTRACT The alternative dielectrics like vegetable oils, emulsions, and different organic solutions have captured the emerging research attentions, and few pieces of literature also discussed about their potentiality to replace... more
ABSTRACT The alternative dielectrics like vegetable oils, emulsions, and different organic solutions have captured the emerging research attentions, and few pieces of literature also discussed about their potentiality to replace conventional kerosene. However, observations of the existing literatures are limited up to the assessment of the primary responses like material removal rate (MRR), surface roughness (SR), hardness, etc., which are not sufficient to recommend them as a suitable one. Therefore, the present work intends to incorporate a little bit value-addition to the existing research by including their impacts on the crater-overlapping, debris-agglomeration, surface integrity, and recast-layer thickness of the EDM-surface. Here, the machining is performed on the titanium alloy ‘Ti6Al4V’ using a cylindrical copper tool with various flushing pressures, and the obtained outcomes are compared with that of conventional kerosene. Findings claim the presence of spikes, black spots, and discrete thermal defects with comparatively thinner recast thickness when bio-dielectric was used. Moreover, comparatively 20.75% higher MRR, 16.68% less SR, and 18.75% more tool wear rate (TWR) are noticed for bio-dielectric within the permissible range of the flushing pressure, but beyond this range, 4–6.5% reduction in MRR and 26.00–31.5% increment in TWR are observed.
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Abstract The micro-part manufacturing can be accomplished by the execution of different micro-machining techniques. The sequential machining is one of the most promising techniques which dictate the structured approach towards the... more
Abstract The micro-part manufacturing can be accomplished by the execution of different micro-machining techniques. The sequential machining is one of the most promising techniques which dictate the structured approach towards the fabrication of highly precise micro-features in sophisticated components. The newly coined Sequential Electro Micro Machining (SEMM) technique has been implemented for the improvement of overall machining efficiency and enhancement in surface characteristics of the part during machining. In the chain of sequential machining, the present research paper has introduced a novel sequential combination of micro Wire Electro Discharge Machining (µWEDM) and micro Wire Electro-Chemical Machining (µWECM) processes. The µWEDM process was carried out on the standard wire cut EDM machine, whereas µWECM was performed on indigenously designed and developed system setup. The micro-grooves on difficult to cut material such as titanium alloy (Ti6Al4V) was initially generated by applying µWEDM process. The µWEDM is a thermal process, where the shaping of micro-groove was accomplished rapidly due to the existence of high-intensity spark discharges. The spark produced also generates recast layer comprising of cracks, micro-pores and numerous micro-craters in the heat affected zone of the machined region. During experimentation, the micro-groove using µWEDM process was cut at different machining voltages. In order to make out the best sequential machining combination, the machining voltage at which the least surface defects occurred on micro-groove was selected for sequencing with the subsequent process. In present experimentation, the least width overcut of the groove was obtained at 10V. The µWECM process was then applied to ameliorate the surface defects and other irregularities imparted to micro-groove during the µWEDM process. The effects of machining process parameters in µWECM, such as applied voltage, machining time and duty ratio on µWEDMed part was investigated. The sequential machining experiments were then conducted by choosing the best input process parameters in both the processes. The experimental results thus obtained after the application of diversified sequential micro-machining processes revealed an improved machining efficiency and high surface quality of micro-groove. Thus the µWEDM process for shaping the groove and µWECM process for finishing the groove was conducted successfully
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Low removal rate, high power consumption, and dependency on conventional fuels (kerosene as a dielectric) are some premier issues that keep the sustainability index of EDM low, though it has huge acceptability and popularity mostly in... more
Low removal rate, high power consumption, and dependency on conventional fuels (kerosene as a dielectric) are some premier issues that keep the sustainability index of EDM low, though it has huge acceptability and popularity mostly in aviation sectors and biomedical instrumentation to machine some extensively hard ferrous and nonferrous metal/metal alloys. Besides these, the thermal agitation inside the fusion/machining zone partially burns the dielectrics and tool–workpiece–metal, which evolve some oxides/monoxides. These evolved gases promote an unhygienic breathing atmosphere, which is very much harmful to the operator’s health. Sometimes because of inadequate flushing pressure and velocity, carbon particles deposited inside the crater makes the spark unstable and releases carbon monoxide when the temperature exceeds its melting point. According to ISO 14000, every manufacturing process must be comprised of the sustainability criteria, which maintains a compromised balance between the economic, environmental, and social aspects, including the issue of the operator’s health. But in real practices, it is very tough to maintain a stoichiometric balance between all these constraints. The article intensely focuses on the issue of emergence of gases during machining and tries to promote the utility of some alternative vegetable oil-based dielectrics, which are experimentally justified as a potent alternative of conventional kerosene. Apart from these, it includes some comparative talks on dielectric nature and their impacts on the responses and surface properties. Finally, this article highlights some compromise solutions which are probably capable of mitigating the hurdles to some extent, so that the sustainable machining can be encouraged in real sense.
The electro-chemical discharge micro-machining (µ-ECDM) process can be utilised as a potential micro-machining process, which offers several advantages such as cost-effectiveness and diversity in applications on electrically... more
The electro-chemical discharge micro-machining (µ-ECDM) process can be utilised as a potential micro-machining process, which offers several advantages such as cost-effectiveness and diversity in applications on electrically non-conducting hard brittle materials like glass. The present research article includes the analysis of material removal rate (MRR), width of cut (WOC), heat affected zone (HAZ), and surface roughness (Ra) during µ-channeling on glass with a micro-ECDM process, considering applied voltage (V), electrolyte concentration (wt%), and tool shapes as process parameters. A comparative study is conducted to select the suitable tool shape and electrolyte. Moreover, the optical and SEM images are used to examine HAZ, WOC and topography of µ-channels. MRR and WOC enhance with the rise of applied voltage for fixed electrolyte concentration and vary with tool shape. Surface roughness (Ra) is found low at applied voltage of 55V and 60V for both electrolytes when straight and ...
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In the present experimental study, percussion micro-drilling on quartz is carried out by Ytterbium (Yb3+) doped 50 W fibre laser system in order to find out the effects of various process parameters such as laser power, pulse frequency,... more
In the present experimental study, percussion micro-drilling on quartz is carried out by Ytterbium (Yb3+) doped 50 W fibre laser system in order to find out the effects of various process parameters such as laser power, pulse frequency, duty cycle and assist air pressure (process parameters) on the response criteria, i.e., taper angle, circularity for the entrance holes and heat affected zone (HAZ) thickness. The larger and smaller diameters of the micro-holes at the entry side are measured as 124.13 µm and 68.17 µm respectively, whereas the larger and smaller diameters of micro-holes in exit side are 111.65 µm and 58.88 µm respectively. The smaller value of the taper angle (θ) is found at 0.187° along with the smaller HAZ thickness of 16.10 µm at the entry side. In addition to this, greater entrance hole circularity is measured as 0.938 during fibre laser percussion micro-drilling on quartz materials.
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Increased surface area at the cross section of varied cross-sectional microgroove improves the product performance; hence, complex microgrooves of different cross sections are machined on various micro-products. Fabrication of straight... more
Increased surface area at the cross section of varied cross-sectional microgroove improves the product performance; hence, complex microgrooves of different cross sections are machined on various micro-products. Fabrication of straight microgroove on metallic surfaces is simple, whereas machining of varied cross-sectional microgroove on metallic surfaces becomes the challenging task from the aspects like fabrication of complex shaped microtool and suitable microgroove manufacturing process. Very few methods are capable to machine such complex shaped microgrooves. This chapter explores the potential of machining varied cross-sectional microgrooves on metallic surfaces by electrochemical micromachining. Important process parameters such as applied voltage, duty ratio and machining time have been controlled along the depth while machining the microgrooves. Influences of these parameters on width have been investigated, and results have been applied to devise the machining guidelines to fabricate varied cross-sectional microgrooves. The guidelines for machining straight, reverse tapered, barrel-shaped, double stepped, spherical based and microgroove with internal pocket have been developed. Finally, fabrications of these microgrooves have been demonstrated successfully by following developed guidelines. The developed guidelines can be applied for machining complex microgrooves for micro-coolers, micro-reactors and micro-mixers that need definite shape and size for their working.
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Ultrasonic micromachining (USMM) has immense potential for micro-machining on quartz which is used in different field of applications such as optics, metrology and micro electro mechanical system (MEMS) etc. In this paper the influences... more
Ultrasonic micromachining (USMM) has immense potential for micro-machining on quartz which is used in different field of applications such as optics, metrology and micro electro mechanical system (MEMS) etc. In this paper the influences of process parameters such as power rating, abrasive slurry concentration and tool feed rate on material removal rate (MRR), overcut and taper angle of the micro hole on quartz by USMM have been investigated. Stainless steel of grade 304 has been selected as the micro-tool material for ultrasonic micro drilling on quartz. The higher value of MRR of 0.4235 mm/min has been obtained at power rating of 400 W, abrasive slurry concentration of 40% and tool feed rate of 1.2 mm/min. The lower value of overcut of 55 µm and taper angle of 0.600 of micro hole have been obtained at abrasive slurry concentration of 20%, power rating of 300 W and tool feed rate of 1 mm/min.
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The Electric Discharge Machining is one of the popular non-traditional approaches which has huge utility in industrial sectors, mostly in die-making industries and as well as in bio-medical fields. But more power consumption, evolvement... more
The Electric Discharge Machining is one of the popular non-traditional approaches which has huge utility in industrial sectors, mostly in die-making industries and as well as in bio-medical fields. But more power consumption, evolvement of unhygienic gases, development of non- biodegradable wastes, etc. are some curtail issues, which leads the poor sustainability of the EDM operation. In this approach, transesterified neem is introduced as a new and green dielectric medium of EDM, and its impacts on EDM responses are examined. Here, machining is carried out between 4 A to 10 A ranges of input current, 100 μ-sec to 200 μ-sec of pulse ON time and 10 μsec to 30 μ-sec of pulse OFF time using both kerosene and transesterified neem as a dielectric medium. The responses like MRR, surface roughness, and microscopic views of machined surfaces are analyzed to check the viability of transesterified neem as a dielectric medium of EDM.It is experimentally observed that transesterified neem as a ...
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Quartz has been broadly applied in industries including electronics, optics, micro electromechanical system (MEMS), biomedical. Micro ultrasonic machining (Micro USM), is a non traditional micro machining technique, extensively used to... more
Quartz has been broadly applied in industries including electronics, optics, micro electromechanical system (MEMS), biomedical. Micro ultrasonic machining (Micro USM), is a non traditional micro machining technique, extensively used to produce micro features and parts on quartz, silicon, ceramics and glass. A micro tool of stainless steel having diameter 330µm has been develop for generating micro hole on quartz. Experiments have been done by using different types of abrasives like boron carbide, silicon carbide and aluminum oxide of average grain size 14 µm. Experiments have been performed under different parametric setting of tool feed rate and power rating. The range of tool feed rate is 0.8 to 1.1 mm/min. The range of power rating is 200 to 500 W. Micro hole has been generated on quartz. Overcut and taper angle has been considered as response of micro ultrasonic drilling. In the present research effect of tool feed rate and power rating on taper angle and overcut has been invest...
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Sequential micro machining (SMM) is a strategy of machining applied for micro-part manufacturing. Due to the finding of new sequential machining combinations, the authors have presented a novel combination of micro-ECDM (µECDM) drilling... more
Sequential micro machining (SMM) is a strategy of machining applied for micro-part manufacturing. Due to the finding of new sequential machining combinations, the authors have presented a novel combination of micro-ECDM (µECDM) drilling and micro-ECM (µECM) finishing for producing micro-holes in SS-304 stainless steel. An experimental setup was developed indigenously to conduct both machining processes at one station. The sequential processes were employed with desirable machining parameters, during their individual execution. The most desirable parameter like machining voltage, for hole drilling by µECDM was decided by studying hole taper angle, radial overcut, etc. The µECDM generates a recast layer, to overcome the adverse effects of µECDM, with the µECM finishing applied subsequently. The experimental results of SMM indicate a reduction in hole taper angle, improved circularity, and better surface quality. The change of phase of material due to sequencing of µECDM and µECM proce...
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In the present era, μ-EDM is a promising non-conventional micro-machining process for drilling as well as cutting of electrically conductive materials in the micron range. The objectives of the present research work is to investigate the... more
In the present era, μ-EDM is a promising non-conventional micro-machining process for drilling as well as cutting of electrically conductive materials in the micron range. The objectives of the present research work is to investigate the influence of various parameters such as peak current, pulse ON-time, working time, and aluminium powder concentration on circularity and to find out the significant process parameters based on Taguchi method during micro hole drilling on Monel K-500 with the help of an EDM set-up. Further, a mathematical model has been developed to correlate the relationship between process parameters and circularity based on Response Surface Methodology (RSM). Circularity is increased from 1 to 1.5 A of peak current, from 0.5 to 1.5 sec of working time and from 1 to 4 gm/lit of aluminium concentration. The maximum value of circularity is obtained as 0.976 at the parametric combination of 1.2 A of peak current, 1.8 sec of working time and 3.33 (gm/lit) of Al powder ...
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Abstract This article deeply focused on the sustainability issues of EDM and evaluated the feasibility of transesterified jatropha, canola and neem oil as an alternative of conventional kerosene. Therefore these bio dielectrics are judged... more
Abstract This article deeply focused on the sustainability issues of EDM and evaluated the feasibility of transesterified jatropha, canola and neem oil as an alternative of conventional kerosene. Therefore these bio dielectrics are judged in terms of removal rate, surface integrities, taper cut and overcut under various ranges of process parameters and flushing velocities. More over computational fluidics and electro thermal modeling are also used to investigate the heat dissipation patterns and crater formations of both conventional (kerosene) and bio dielectrics under various flushing velocity. It is observed that all the bio dielectrics ensure better MRR and less SR than kerosene but out of them the performances of jatropha and canola are remarkable in so far MRR and SR are concerned. The obtained results indicate that due to less axial and wider radial extension of the developed crater the neem dielectric exhibits 18% more overcut and 40% more tapper cut than kerosene and on the other hand canola ensures 12% less SR because of the same reason. But the developed surfaces subject more heat affected zone and thermal cracks because of poor heat dissipation rate, higher viscosity and less flowability of the bio dielectrics. Moreover these bio dielectrics do not exhibit impressive MRR at low flushing velocity (
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Micro-electro-discharge machining (micro-EDM) process has great potential to machine difficult-to-cut and electrically conducting materials like aluminium, nickel, titanium and their alloys etc. This present research work intends to... more
Micro-electro-discharge machining (micro-EDM) process has great potential to machine difficult-to-cut and electrically conducting materials like aluminium, nickel, titanium and their alloys etc. This present research work intends to investigate during micro-holes drilling on pure aluminium by means of vibration at workpiece in electro-discharge machining process. The influences of different process variants such as polarity, peak current, direction of flushing and pulse on-time have been studied using experimental results, which were obtained based on L18 orthogonal array of Taguchi method and the suitable parametric combinations for optimum machining criteria have been searched out. Also, the effects of vibration on different machining performances, as well as surface quality and accuracy of the micro-holes have been investigated with a rotary vibrator, which has been indigenously designed and developed. The performance characteristics such as metal removal rate (MRR), tool wear rate (TWR) and roundness have been found to be improved on account of influence of the vibration of workpiece.
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Research Interests:
The essence of the “ratio data” in cellular manufacturing system has rarely been correctly emphasized since past few decades of research and study. This article is an attempt to deal with cell formation problem which exploits machine... more
The essence of the “ratio data” in cellular manufacturing system has rarely been correctly emphasized since past few decades of research and study. This article is an attempt to deal with cell formation problem which exploits machine utilization percentage and eliminates the “fuzziness” on the subject of ratio data. In the course of this study, a distinctive technique is adopted based on multi-criteria decision technique with significant modifications which is experimented on test data and compared with published methodology. To verify the grouping result, a novel performance measure is proposed and elaborated analytically to establish its superiority and robustness over the earlier efficiency measures published in the past literature of cellular manufacturing system. The novelty of this research remains in eradicating ambiguities on the subject of “ratio data,” imposing appropriate rules while generating the test problems, catering a unique multi-criteria decision technique–based a...
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Electrochemical discharge machining (ECDM) process has great potential to machine hard, brittle and electrically non-conducting materials in micron range. The objective of this paper is to investigate into electrochemical discharge... more
Electrochemical discharge machining (ECDM) process has great potential to machine hard, brittle and electrically non-conducting materials in micron range. The objective of this paper is to investigate into electrochemical discharge micro-machining on electrically semi-conductor type silicon carbide (SiC) material so as to study the effects of applied voltage, electrolyte concentration and inter-electrode gap on material removal rate (MRR) and radial overcut (ROC) of micro-drilled hole. Experiments were conducted based on L9 array of Taguchi method with stainless steel µ-tool of 300µm diameter using NaOH electrolyte. An attempt has been made to find out the single as well as multi-objective optimal parametric combinations for maximum MRR and minimum ROC. The single-objective parametric combinations were selected as 45V/20wt%/20mm and 25V/20wt%/40mm for maximum MRR and minimum ROC respectively whereas multi-objective optimal parametric combinations was found as 25V/20wt%/40mm. Further...
In the present era, fiber lasers have been successfully replacing Nd-YAG and CO2 lasers along with other conventional laser systems for various micro-machining applications such as micro-cutting of stents, thin sheet of ferrous and... more
In the present era, fiber lasers have been successfully replacing Nd-YAG and CO2 lasers along with other conventional laser systems for various micro-machining applications such as micro-cutting of stents, thin sheet of ferrous and non-metals in terms of cutting speed, cut edge quality and the length of micro cracks. The usage of fiber laser can also be observed in field of micro-machining of various engineering materials owing to the characteristics of short pulse lengths which range from millisecond to picosecond or even femtosecond. The present chapter aims to carry out an in depth study of the fiber laser micro-machining, i.e., micro-cutting, micro-drilling, engraving, marking, etc., of engineering materials ranging from polymer to ceramics. The aim of the chapter is also to include an overall concept of fiber laser micro-machining system in the present scenario and its applications along with the occurring physical phenomena and influence of various process parameters on the fiber laser generated micro-features.
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Product miniaturization is the principal driving force for 21st century’s industries because of the escalating demands for compact, intelligent, robust, multi-functional, and low cost products in all fields. As demand of miniaturized... more
Product miniaturization is the principal driving force for 21st century’s industries because of the escalating demands for compact, intelligent, robust, multi-functional, and low cost products in all fields. As demand of miniaturized products is exponentially increasing, the need to manufacture such products from advanced engineering materials becomes more apparent. Micromachining plays significant role in miniaturization, and consist of machining different microfeatures on products. Design of microtools, tool wear, surface quality, burr and heat removal are the main challenges in various micromachining methods. Electrochemical micromachining is one of the important techniques because of its special material removal mechanism, better precision and control, environmentally acceptable, and mainly it permits machining of any metallic materials irrespective of its hardness. For better understanding of EMM process, the basic concepts such as electrochemistry, Faraday’s laws of electrolysis, electrical double layer, equivalent electrical circuit, and material removal mechanism have been discussed. Significant process parameters which affect the process performance, need of EMM setup development, various subsystems, along with the challenges in setup developments, and important techniques for improving the machining accuracy have been highlighted. Machining, finishing, and surface engineering applications of EMM, as well as recent advancement in EMM for micro and nanofabrication have also been discussed.
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Electrochemical discharge micro-machining (micro-ECDM) process appears to be very promising as a future micro-machining technique, since in many areas of applications it offers several advantages, which include machining of variety of... more
Electrochemical discharge micro-machining (micro-ECDM) process appears to be very promising as a future micro-machining technique, since in many areas of applications it offers several advantages, which include machining of variety of electrically non-conducting hard, brittle materials including glass, ceramics and composites etc. It is an advanced hybrid micro-machining process that combines the techniques of electrochemical machining (ECM) and electrodischarge machining (EDM). This book chapter focuses on the current researches and developments in micro-ECDM process . The chapter discusses in details about the micro-ECDM system, which includes the mechanical hardware unit, electrolyte supply unit and electrical power supply unit etc. The effects of various factors on different machining performance characteristics such as material removal rate, accuracy, heat affected zone, gas film quality, machining depth, surface topography and tool wear etc. during its application mainly for micro-drilling and micro-cutting operations on engineering materials are represented in this chapter. The chapter also gives a glimpse on the fundamentals, problematic areas and applications of micro-ECDM process and highlights the challenges and future possibilities of research in this area. The recent advancements for improvement of performance of µ-ECDM process by using the rotating and travelling micro-tool, controlling the gap between the tool and the workpiece, changing the shape of micro-tool and also controlling the surface texture and material of tool for micro-spark discharge for required micro-machining operations are also depicted in this chapter. The chapter is expected to open up new insights into the process characteristics for successful application of electrochemical discharge micro-machining (micro-ECDM) process and provides valuable guidance to the applied researchers and manufacturing scientists for setting up unique platform for micro-machining electrically non-conducting engineering materials.
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Laser micro-turning process is one of the newly developed laser material processing technologies to generate micro-turned groove or surface on cylindrical workpiece. In the present paper, an attempt has been made to investigate the laser... more
Laser micro-turning process is one of the newly developed laser material processing technologies to generate micro-turned groove or surface on cylindrical workpiece. In the present paper, an attempt has been made to investigate the laser micro-turning operation on cylindrical shaped aluminium oxide (Al 2 O 3 ) ceramic to study the influence of different laser micro-turning process parameters namely, laser average power, pulse frequency, workpiece rotational speed, assist air pressure and Y feed rate using response surface methodology (RSM) experimental plan. The mathematical model for surface roughness (Ra) has been developed and the adequacy of the model has been tested through analysis of variance (ANOVA) results. Average power and pulse frequency are the most significant process parameters. Optimal parametric combination for minimum value of surface roughness has been achieved as 5.23μm at parametric setting of average power of 9.04 W, pulse frequency of 4108.18 Hz, workpiece rotational speed of 451.16 rpm, air pressure of 1.44 kgf/cm 2 and Y feed rate of 0.37 mm/s. Confirmation experimental results show a good agreement between RSM based optimal and experimental value of response criterion.