Advanced Machining Technique Research Articles

Multi-Objective Optimization of Aluminium Powder-mixed EDM process using GRA and TOPSIS Technique based on Fuzzy AHP approach

Electric discharge machining is an advanced machining technique. Spark is initiated between the tool and work piece interface which has a gap between them. Low material removal rate as well as low surface finish is a major concern of this process. Therefore, Powder mixed electric discharge machining is developed. In PMEDM process, powders like silicon, aluminium, chromium, manganese, etc. are circulated along with dielectric fluid in a particular proportion. In this present study, aluminium powder is mixed in the dielectric fluid. The responses such as material removal rate, tool wear rate and surface roughness are measured by considering current, pulse on time and aluminium powder concentration as process parameters. Response surface methodology along with Fuzzy AHP TOPSIS and Grey relational analysis are used for optimization.

Process parameter optimization in laser cutting of Coir fiber reinforced Epoxy composite - a review

Composite materials are progressively being employed in the aerospace, automotive, aeronautics, and marine sectors because of their high strength-to-weight ratio. Traditional machining methods have trouble machining composite materials. However, laser cutting provides an alternative quality machining method that can be accomplished by regulating various process variables. A commonly used thermally dependent non-contact advanced machining technique is laser cutting. The efficiency of the laser cutting method is the subject of extensive study. Analytical approaches based on Regression analysis, and Response surface methodology (RSM) are all standard techniques for solving optimization issues in laser cutting utilizing the Taguchi method. The main theories and practices used in the Taguchi method are explored in this article, as well as a summary of the Taguchi method. The paper discusses research study based on the implementation of the Taguchi method for laser cutting process optimization after examining the parameters as well as performance requirements of the laser cutting process and further concluded that most of the performance characteristics studied (kerf taper, and deviation) as well as surface quality was found to be related (surface roughness). In addition, the Taguchi method has only been utilized to increase metallurgical properties (HAZ, Burr inclusion) and production efficiency (MRR). Taguchi method, being a model-free optimization technique, restricts further level interpolation or extrapolation. It was also reported that to address this shortcoming of the Taguchi method, it was combined with response surface methodology to get optimal results. This paper offers a review of the literature's findings and addresses the problems that need to be discussed.

Investigations on piezo actuated micro XY stage for vibration-assisted micro milling

Vibration assisted machining is an advanced non-conventional precision machining technique aiming at improving the machining performance by superimposing a small amplitude, high-frequency vibration either on the tool or on the workpiece. This article presents the mechanical design, electromechanical simulation, and experimentation on the developed prototype of the flexural hinged micro XY stage for the vibration-assisted micro-milling system. The micro XY stage comprises three layers of flexural hinge structure surrounding the central parallel kinematic structure. The finite element analysis method is adopted to evaluate the static structural stiffness and harmonic behaviour. Two multilayer piezoelectric stack actuators drive the micro XY stage in X and Y directions. The experimental results show that the micro XY stage has a vibrating work area of 17.06 µm × 17.11 µm with a hysteresis nonlinearity and cross-coupling displacements on both axes. Therefore, an electromechanical model is essential to compensate for the hysteresis behaviour and cross-coupling displacements. Open-loop tracking control experiments determine the accuracy of the developed electromechanical model. Implementing a combined hysteresis and cross-coupling displacement compensation approach into the electromechanical model resulted in an open-loop tracking error of 7% for the synchronised circular path and a maximum deviation of 0.6 µm from the linear path.

Abrasive water jet machining techniques and parameters: a state of the art, open issue challenges and research directions

Recently, different problems in manufacturing operations namely lower product time, secondary operations, waste reduction, miniaturization, high-level precision ability, better surface, complex-shaped profiles and high strength material machining are solved with the usage of superior machining methods. The abrasive water jet machining (AWJM) process is further established based on various advanced machining techniques by the researchers. In the manufacturing industries, the AWJM process is used to determine extensive use for a wide range of machining materials. This survey is categorized into different kinds of AWJM processes based on certain parameters to be precise which are factor influences, work materials and modeling process of AWJM. AWJM influences parameters are categorized into subparameters which include mixing parameters, hydraulic parameters, cutting parameters and abrasive parameters. Additionally, we investigated a few modeling processes in AWJM such as dimensional analysis, statistical model, differential equation, neural network model, numerical model and analytical model. The review papers were collected from the year 2009 to 2019, and approximately 78 papers are used for this examination. Additionally, the comparative analysis is carried out between the different numbers of papers chosen for each experiment and their performances were established in this work. Several open issues challenges namely low material removal rate, low depth of penetration, etc. with its future scopes are addressed.

Machining of thin sections using multi-pass wire electrical discharge machining process

The increasing application of fine metallic sections in various sophisticated areas has led to the growth of advanced machining technique to produce thin metallic sections. Wire electrical discharge machining process can prove to be an effective means to machine such sections. The current work identifies the thin wall machining of H13 tool steel using Taguchi's design. An optimal parametric setting is identified using a regression model for lower kerf width (kf) and higher machining rate. The decrease in kf and increase in machining rate is found to be highly dominated by the variation of the input parametric conditions. Machining of thin wall sections is performed to identify the extent of minimum sections that can be machined. A mesh-like structure is observed with wall thickness of less than 80 μm. Further, to improve the surface and edge characteristics, multi pass trimming process is incorporated.

Investigation of WEDM process parameters of Al–SiC–B4C composites using response surface methodology

Aluminum based composites are widely used in various engineering applications. Though the processing of these materials is easy, it requires advanced machining techniques to cut the same as it becomes harder after the addition of ceramic reinforcements. The wire electrical discharge machining (WEDM) process is employed for cutting of Al–SiC–B4C hybrid metal matrix composites with the varying machining conditions. The machining factors, namely current (12A–20A), pulse on time (100μs–120 μs), the wire feed rate (6 mm/min – 10 mm/min) and the content of B4C (weight percentage) in the composite are considered for the performance evaluation. A response surface methodology (RSM), the multi-objective optimization technique is adopted for determining the influence of parameters on the machining features like kerf width and cutting speed. The experimental analysis revealed the correlation between the input and output characteristics. The minimum kerf width of 0.271 mm is attained at a wire feed rate of 10 mm/min and current of 12 A. The maximum cutting speed of 4.76 mm/min is achieved at a pulse on time of 110 μs and a wire feed rate of 8 mm/min. The optimum machining condition obtained through RSM method is current of 20 A, pulse on time of 108.6 μs, wire feed rate of 10 mm/min and 5.65% of the B4C content in the composites.

Effective parametric analysis of machining curvature channel using semicircular curved copper electrode and OHNS steel workpiece through a novel curved EDM process

Electro-discharge machining (EDM) is one of the advanced non-conventional machining techniques used in industries. Most of the EDM research areas are directed towards the linear movement (up-and-down) of the electrode. Through a novel innovation, an innovative way of machining a curvature channel through a semicircular curved copper electrode is possible through curved EDM process. The experimental setup is developed and installed on the Z-axis numerically controlled(ZNC)EDM machine. The oscillating motion of curved electrode on stationary workpiece is obtained by implementing the concept of mechatronics. In this present work, we attempt to investigate the effect of input machining parameters on the output performance characteristics in curved EDM process. During pilot experimentation, critical variables are identified and selected as sparking current, pulse on time, pulse off time and angular sensitivity. Design of Experiment using Taguchi (L9) is used to formulate the planned experiments and to evaluate the effects of input machining characteristics on Material Removal Rate (MRR), Electrode Wear Rate (EWR), Curved Machining Angle (CMA), and Curvature Depth (L). Regression analysis and Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS) are effectively used to validate the model developed for the curved machining. The results obtained after experimentation predicts that the model can be accepted to optimize the quality machining characteristics in curved EDM process. Geometrical analysis and surface roughness are evaluated for the machined curvature through the advance measuring equipment’s. Scanning Electron Microscopy (SEM) is also used for observing the microstructure at higher magnification of workpiece material before and after machining.

Metaheuristic approach in machinability evaluation of silicon carbide particle/glass fiber–reinforced polymer matrix composites during electrochemical discharge machining process

The advanced manufacturing and machining techniques are adopting a population-based metaheuristic algorithm for production, predicting and decision-making. Using the same approach, this paper deals with the application of bees algorithm and differential evolution to forecast the optimal parametric values aiming to obtain maximum material removal rate during electrochemical discharge machining of silicon carbide particle/glass fiber–reinforced polymer matrix composite. The bees algorithm follows swarm-based approach, while differential evolution works on a population-based approach. The experimental design was prepared on the basis of Taguchi’s methodology using an L16 orthogonal array. For the experimental analysis, the main variables in the process, that is, electrolyte concentration (g/L), inter-electrode gap (mm), duty factor and voltage (volts), were selected as main input parameters, and material removal rate (mg/min) was adjudged as output quality characteristic. A comparative investigation reveals that the maximum material removal rate was obtained by the parametric value proposed by differential evolution that follows the bees algorithm and Taguchi’s methodology. Furthermore, the results prove that the differential evolution algorithm has better collective assessment capability with a rapid converging rate.

Evaluacija kvaliteta geometrijskih karakteristika rezanja pulsnim Nd:YAG laserom hibridnog kompozita ojačanog Kevlar-29/Basalt vlaknima primenom Grejove relacione analize bazirane na genetskom algoritmu

In advanced machining techniques, laser beam cutting provides better control over the cut surface geometry in the cutting of fiber reinforced composites compared with conventional machining techniques due to its non-contact and localized processing. However, the performance of laser cutting for hybrid fiber reinforced polymer composites is yet to reveal. It has paved the way of present study, which reports on the pulsed Nd:YAG laser cutting of 1.35mm thick Kevlar-29 and Basalt fiber based hybrid composite sheet. The geometrical accuracy of the cut has been evaluated by the measured values of kerf width, kerf deviation, and kerf taper for 42 different combinations of five laser-cutting parameters such as lamp current, pulse width, pulse frequency, compressed air pressure and cutting speed. Moreover, an integrated approach based on Grey relational analysis and genetic algorithm (GRGA) has been used for the single index optimizations of different kerf qualities. Furthermore, parametric effects have been also discussed.

A Novel Approach for Minimization of Tool Vibration and Surface Roughness in Orthogonal Turn Milling of Silicon Bronze Alloy

The advanced manufacturing system is aimed to produce components at right quantity, quality and cost. Turnmilling is one of the advanced machining techniques that combines turning and milling processes for high metal removal rate. In orthogonal turn milling, bottom surface of the end mill cutter removes material from the surface of a rotating workpiece. Optimization of process parameters plays an important role in machining to improve quality and productivity and reduce production cost. In the present work, an advanced teaching learning based optimization (TLBO) technique was introduced to optimize process parameters in orthogonal turn milling of Silicon Bronze. Experiments were conducted at five levels of cutting speed, feed and depth of cuts. Experimental results of surface roughness and amplitude of cutter vibration were analysed using analysis of variance. The experimental results were also used to optimize process parameters through TLBO. Experiments were also conducted using TLBO optimized process parameters and the results were compared with TLBO results. The TLBO results were found to be in good agreement with target values of the responses. Artificial neural networks were developed for the surface roughness and amplitude of cutter vibration to verify optimization.

Enhancing thermal performance of a two-phase closed thermosyphon with an internal surface roughness

Abstract Enhancement of energy conversion devices has become an important task to reduce size and cost, and design efficient systems. In this work, enhancement of heat transfer performance of a two-phase closed thermosyphon has been investigated by making an internal surface roughness. Thus, a new advanced machining technique (Electrical Discharge Machining) is employed to modify the surface characteristics of a TPCT. The experimental work has been carried out at two initial sub-atmospheric pressures (3 and 30 kPa), heat input range of (90–160 W) and a fill ratio of 50% using water as a working fluid. The results of the new thermosyphon have been compared with a plain copper TPCT to consider the enhancement in thermal performance resulting from resurfacing of the thermosyphon wall. The results revealed that using internal wall roughness in TPCT can enhance its thermal performance by reducing the evaporator temperature, thereby the total thermal resistance decreasing by about 42% and 13% at initial pressures of 3 kPa and 30 kPa, respectively. On the other hand, the evaporator thermal resistance decreases and the evaporator heat transfer coefficient increases by about 115% and 68% at initial pressures of 3 kPa and 30 kPa, respectively. However, the condenser thermal performance decreases using the resurfaced TPCT compared with plain thermosyphon.

Machinability of Nickel Based Superalloys: A Review

Nickel based superalloys are generally known difficult to machine materials because of their toughness, high heat resistance and high operating temperatures, hardness, strength to weight ratio and chemical property to react with tool materials, low thermal conductivity and creep resistance. Although these whole properties are necessary design requirements, they cause a greater challenge to manufacturing engineers due to the high temperatures and stresses generated during machining. The tool materials with better hardness like carbides, ceramics and CBN are regularly used for machining of Nickel based Super alloys. Betterments in machining productivity can be attaining with the advanced machining techniques such as rotary machining. The Nickel based superalloys mainly used to turbine parts as well as high temperature elements. This paper presents a detailed review of the development, classification, applications of Nickel based superalloys. And also presents processing of Nickel based superalloys including microstructure, tool materials, and effect of cutting parameters, and use of coolant supply and the integrity of machined surface.

A Review on Cryogenic Machining of Super Alloys Used in Aerospace Industry

The present work reviews the work done on cryogenic machining of super alloys around the four continents i.e. North America, Europe Asia and Australia. Cryogenic machining has emerged as one of the most effective procedure among the advanced machining techniques for machining super alloys. Along with that, the coating on the tool also plays a crucial role in cryogenic machining. It is found that, North American research focuses on cryogenic machining of innovative materials like shape memory alloys and ceramics. European research focuses on application of cryogenic as well as MQL techniques and studying the different types of wears and surface integrity. Several authors have also presented innovative nozzle geometries which increases cooling efficiency in cryogenic machining. Whereas Asian research focuses on tribological performance of cryogenic coolants using advanced manufacturing techniques like WEDM and using several types of coatings on tools. Australian Research focuses on tool wear and surface roughness of machined surface. More specifically, special attention is given to the main findings obtained over the last couple of years from the various authors collaborative research on cryogenic machining of super alloys, through the experimental investigations.

Analysis of tool wear in ultrasonically assisted turning of -Ti-15V-3Al-3Cr-3Sn alloy

An extremely high tool wear rate in the machining of titanium alloys (Ti alloys) is one of the major reasons limiting the use of conventional machining processes for the components made of these alloys. The machinability of a -Ti-15V-3Al-3Cr-3Sn (Ti- 15333) alloy can be signi cantly improved using an advanced machining technique known as Ultrasonically Assisted Turning (UAT). The key mechanism of tool wear associated with UAT of Ti-15333 alloy is still unknown. The present study begins to address this issue by examining wear behaviour of two di erent types of cutting inserts using UAT and Conventional Turning (CT) of Ti-15333 alloy. Tool wear was measured using 3D optical microscope and the composition of the Built-Up Edge (BUE) on the worn tools was analysed with scanning electron microscopy. A robust experimental methodology was developed, which provided repeatable and statistically reliable tool wear results. The KC5510 cutting inserts demonstrated better tool-life in UAT when compared to CP-500 inserts.

Analysis of mechanism based on two types of pulse generators in micro-EDM using single pulse discharge

Micro-electrical discharge machining (micro-EDM) has become an advanced machining technique in recent times. In the micro-EDM process, the power supply unit (PSU) is an important component because of its considerable influence on the machining parameters. Additionally, there are two main types of pulse generators: RC- and transistor-type pulse generators. In this study, a series of novel analyses and experiments featuring the mechanisms of each of the two types of pulse generators were conducted using single discharge pulse. The discharge characteristics of the two types of generators were discussed first. Then, the differences in their discharge channel radii when using the plasma model with single pulse were presented. In addition, their thermal effects were analyzed using the thermal heat model with single pulse. Lastly, a train of related single pulse discharge experiments was carried out using the two different pulse generators with varied simulation parameters in order to observe real phenomena in micro-EDM. The results of experiments were consistent with those of simulations, and the two different pulse generators can be applied to different situations, depending on the machining circumstances, as a result of their different machining characteristics. The findings of this study are expected to help guide the selection of the pulse generator type based on parameter requirements in micro-EDM.

Micro Slot Generation by μ-ED Milling

Micro electro discharge machining is one of the most widely used advanced micro machining technique owing to its capability to fabricate micro features on any electrically conductive materials irrespective of its material properties. Despite its wide acceptability, the process is always adversely affected by issues like wear that occurred on the tool electrode, which results into generation of inaccurate features. Micro ED milling, a process variant in which the tool electrode simultaneously rotated and scanned during machining, is reported to have high process efficiency for generation of 3D complicated shapes and features with relatively less electrode wear intensity. In the present study an attempt has been made to study the effect of two process parameters viz. capacitance and scanning speed of tool electrode on end wear that occurs on the tool electrode and overcut of micro slots generated by micro ED milling. The experiment has been conducted on Al 1100 alloy with tungsten electrode having diameter of 300 μm. Results suggest that wear on the tool electrode and overcut of the micro features generated are highly influenced by the level of the capacitance employed during machining. For the parameter usage employed for present study however, no significant effect of variation of scanning speed has been observed on both responses.

Study on Force Characteristics for High Speed Sawing of Quartz Glass with Diamond Blade

High speed sawing is an advanced machining technique for sawing of brittle materials with good component quality and high productivity. In the paper, sawing experiments were carried out to investigate the characteristics of sawing forces by altering many processing parameters in high speed sawing of quartz glass with a diamond blade. The sawing forces and force ratio were analyzed. The conclusions present that in the fixed material removal rate, the increasing of periphery speed can help to lower sawing forces and force ratio; sawing forces increase with material removal rate; in the high speed sawing, the effect of material removal rate on sawing forces is smaller than the one in the low speed.

Finite Element Study of Ultrasonic Elliptical Vibration Turning of Ti6Al4V

Ultrasonic elliptical vibration turning (UEVT) is an advanced machining technique for difficult-to-cut materials, in which with frequency in excess of 20 KHz is superimposed on the cutting tools movement. In order to analyze the effect of vibration frequency on cutting forces and cutting temperature, finite element models of ultrasonic elliptical vibration turning were developed. The cutting forces and the distribution of the temperature on workpiece and cutting tool were predicted. It is observed that the cutting forces and cutting temperature decrease with the increase of the vibration frequency.

Finite Element Analysis and Process Parameters Optimization of Ultrasonic Vibration Assisted Turning (UVT)

In recent years, there have been many modern engineering materials introduced recently which are hard, brittle and difficult to machine. These materials are very difficult to machine with conventional turning methods. Ultrasonic assisted turning (UAT) is a new non-conventional technique, used to remove an unwanted material to produce a desired product. Ultrasonically assisted turning (UAT) is an advanced machining technique, where a high frequency of vibration (frequency f ≈ 20±0.5kHz, amplitude around a ≈ 20μm) is superimposed on the movement of a cutting tool. In this method, high frequency electrical energy is converted into mechanical vibrations via a transducer or booster combination, which are transmitted through a horn or tool assembly. An ultrasonic vibratory tool (UVT) designed and analyzed using ANSYS® (one of the FE code) for the calculation of its natural frequency and working amplitude of vibration. Taguchi with TOPSIS method is used to optimize both cutting force and surface roughness to find the best possible machining parameters under the used experimental working condition in UAT.

Enhanced ultrasonically assisted turning of a β-titanium alloy

Although titanium alloys have outstanding mechanical properties such as high hot hardness, a good strength-to-weight ratio and high corrosion resistance; their low thermal conductivity, high chemical affinity to tool materials severely impair their machinability. Ultrasonically assisted machining (UAM) is an advanced machining technique, which has been shown to improve machinability of a β-titanium alloy, namely, Ti-15-3-3-3, when compared to conventional turning processes.