Unconventional machining

The abrasive waterjet machining process was introduced in the 1980s as a new cutting
tool; the process has the ability to cut almost any material. Currently, the AWJ process is used in
many world-class factories, producing parts for use in daily life. A description of this process and its
influencing parameters are first presented in this paper, along with process models for the AWJ tool
itself and also for the jet–material interaction. The AWJ material removal process occurs through the
high-velocity impact of abrasive particles, whose tips micromachine the material at the microscopic
scale, with no thermal or mechanical adverse effects. The macro-characteristics of the cut surface, such
as its taper, trailback, and waviness, are discussed, along with methods of improving the geometrical
accuracy of the cut parts using these attributes. For example, dynamic angular compensation is
used to correct for the taper and undercut in shape cutting. The surface finish is controlled by the
cutting speed, hydraulic, and abrasive parameters using software and process models built into
the controllers of CNC machines. In addition to shape cutting, edge trimming is presented, with
a focus on the carbon fiber composites used in aircraft and automotive structures, where special
AWJ tools and manipulators are used. Examples of the precision cutting of microelectronic and
solar cell parts are discussed to describe the special techniques that are used, such as machine vision
and vacuum-assist, which have been found to be essential to the integrity and accuracy of cut parts.
The use of the AWJ machining process was extended to other applications, such as drilling, boring,
milling, turning, and surface modification, which are presented in this paper as actual industrial
applications. To demonstrate the versatility of the AWJ machining process, the data in this paper
were selected to cover a wide range of materials, such as metal, glass, composites, and ceramics, and
also a wide range of thicknesses, from 1 mm to 600 mm. The trends of Industry 4.0 and 5.0, AI, and
IoT are also presented.

In this study, a RSM is applied to predict MRR in die sinking EDM for Inconel 600 superalloy with Tungsten carbide (WC) electrode. To investigate the MRR, the main operating parameters peak current (Ip), gap voltage (Vg), pulse-on time (Ton), and duty factor (DF) are taken into consideration. The tests were designed employing a central composite design (CCD) using the usage of statistical software Design-Expert-9.0. RSM created mathematical models for MRR performance characteristic of the EDM process. The studies were carried out with the use of a face-centered-central-composite-design and 30 runs. For assessing and modelling the EDM process parameters for performance characteristic, a common second-order experimental design known as face-centered-central composite-design was used. A mathematical model was created to correlate the effects of these machining parameters and MRR after the of 30 experiments. At a 5% level of significance, ANOVA was performed to obtain the factors that affect the quality. Peak current, pulse on time, and duty factor were revealed from the data to have a substantial influence on the MRR. Confirmation experiments validated the expected optimal range of MRR at 95 percent confidence level, and the MRR was determined to be 20.656 mm 3 /min.

Because of its significant advantages of low thermal influence on workpiece and possibility of cutting different type of materials, the abrasive water jet cutting is more and more present in industry. One of the bigger costs during abrasive water jet cutting is the cost of abrasives. Recommended and required abrasive flow rate is mostly determined by type of workpiece material and its thickness and pump pressure. In intent to reduce the abrasive mass consumption in cutting, some experiments were done and the paper presents the results of changing the abrasive flow rate (mass flow) and its influence on surface cut quality in abrasive water jet cutting. Abrasive saving possibility and also the influence of cutting nozzle distance from workpiece surface on surface cut quality in abrasive water jet cutting are discussed in this paper.

Abrasive waterjet machining is an unconventional process. It consists of using water under high pressure and abrasive particles to machine all materials. This process signi cantly limits the cutting forces and heat that can deform the part and degrade its mechanical characteristics. This is particularly true for very thin ones. The abrasive particles used are most often considered as a xed parameter for this process and it is chosen according to the selected application. It is characterized by a size expressed in mesh and by their material, mainly garnet or alumina. The implicit assumptions are that all the particles have the same size and their composition is constant. In this paper, a characterization of different abrasive garnets is carried out in order to de ne their suitability for machining Titanium alloys. Machining tests are presented and their results are correlated with their properties. 1-Introduction 1.1 The abrasive water jet The rst use of high-pressure water jet cutting by N. Franz was in the 1950s [1], for the production of boards from raw trees. In the 1970s, Hashish developed the pure waterjet cutting process for cutting soft materials such as cardboard, fabrics and frozen food [2]. Nowadays this technology is also used to cut plastics or rubber [2], in the medical eld [3] and to recycle used tires [4]. In the 1980s, abrasive waterjet technology was developed to cut harder materials such as metals. Abrasive particles were introduced into the jet to obtain an abrasive water jet. The functioning of this technology is based on several steps (Fig. 1). First, water is pumped at a high pressure and then passes through a small ori ce. In this second step, the potential pressure energy is transformed into kinetic energy. In a third step the water passes through the mixing chamber where abrasive particles (garnet, alumina, etc.) are added to the water jet. The last step is the focusing of the jet by passing it through a small diameter tube, called a focusing tube. During that step the energy of the water is progressively transferred to the abrasive particles which are accelerated. A high velocity abrasive water jet is thus obtained [5]. 1.2 Material Removal Mechanisms The work of H. Meng and K. Ludema [7] highlights four modes of material removal: cutting, fatigue, brittle fracture and melting. A. W. Momber and R. Kovacevic [8] point out that these four modes act in combination. The importance of each depends on the angle of impact of the particle, its kinetic energy, its geometry and the properties of the target material.

Laser Beam Machining (LBM) is a non conventional process in which material removal takes place through melting and vaporization of metal when the laser beam comes in contact with the metal surface. There are so many process parameters which affect the quality of machined surface cut by LBM. But, the laser power, cutting speed, assist gas pressure, nozzle distance, focal length, pulse frequency and pulse width are most important. However, the important performance measures in LBM are surface roughness (SR), material removal rate (MRR), kerf width, heat affected zone (HAZ) and surface hardness. This paper reviews the research work carried out from the inception to the development of LBM within past few years. It reports on the LBM research relating to performance measures improvement, monitoring and process control, process variables optimization. The paper also discusses the future trend of research work in the area of LBM.

Laser Beam Machining (LBM) is a non conventional process in which material removal takes place through melting and vaporization of metal when the laser beam comes in contact with the metal surface. There are so many process parameters which affect the quality of machined surface cut by LBM. But, the laser power, cutting speed, assist gas pressure, nozzle distance, focal length, pulse frequency and pulse width are most important. However, the important performance measures in LBM are surface roughness (SR), material removal rate (MRR), kerf width, heat affected zone (HAZ) and surface hardness. This paper reviews the research work carried out from the inception to the development of LBM within past few years. It reports on the LBM research relating to performance measures improvement, monitoring and process control, process variables optimization. The paper also discusses the future trend of research work in the area of LBM.

Electric discharge machining (EDM) is one of the most important unconventional machining processes, which can cut hard materials and complex shapes that are difficult to machine by conventional machining processes easily and with high accuracy. In this study, L18 orthogonal array combined with gray relational analysis (GRA) is implemented to investigate the multiple performances characteristics in EDM of DIN 1.2767 Tool Steel. Machining process parameters selected were discharge current (Ip), pulse-on time (Ton), pulse-off time (Toff), and electrode material (copper alloys [NSS and B2]). The investigated performances characteristics were tool wear rate (TWR) and material removal rate (MRR). Analysis of variance (ANOVA) and Taguchi’s signal-to-noise ratio with the help of Minitab-17 software were used to analysis the effect of the process parameters on TWR and MRR. The experimental results and data analysis reveal that TWR and MRR are more affected by Ip and Ton. The minimum TWR was ...

This paper presents the results of experimental research on the behavior of tool-electrodes made of copper, brass, aluminum and graphite by applying pulsed electrical discharges. The electrodes applied to the formation of the surface layers are made of conductive materials subjected to different energetic modes during the experimental investigations. The authors studied the effects that appear between the base electrodes (anode and cathode) varying the polarity and charging voltage of the capacitor while the other regimes remain constant (gap, DEI frequency, capacity and time).

OMAX Corporation Peter H.-T. Liu, Sr. Scientist 21409 72 Avenue South Kent, WA 98032 Email: peter.liu@omax.com Phone: 253-872-2300 x140 MIT, Alex Slocum, Professor, Mechanical Engineering Department 77 Massachusetts Avenue, Cambridge, MA 02139-4307 Email: slocum@mit.edu Phone: 617-253-0012 Boeing Company Barton W. Moenster, Director Advanced Manufacturing RD MS: K2-03 Richland WA 99352 Email: darrell.herling@pnl.gov Phone: 509-375-6905 Oregon State University, Microproducts Breakthrough Institution (MBI), Brian K. Paul, Director, Nano/Micro Fabrication Facility, 204 Rogers Hall, Corvallis, OR 97331 Email: brian.paul@oregonstate.edu Phone: 541-737-7320 Delphi Corporation, Energy and Chassis, Fuel Cell and Reformer Center Karl J. Haltiner, SOFC Stack Team Leader Mail Code: 146-HEN-575, 5500 West Henrietta Road, West Henrietta, NY 14586-9701, Email: karl.j.haltiner@delphi.com, Phone: 585-359-6765

Background: Laser beam machining (LBM) is an emerging engineering process in the field of microparts manufacturing to fabricate the complex shapes of microproducts. Objectives: This machining method has been magnificently employed in machining various materials, starting from aluminum, a highly ductile material, to very hard materials like ceramics and Inconel's. Inconel and Ti-based alloys have a treasure trove of wider applications in these present industries. Methods: In this investigation, an effort is made to study the influence of LBM input parameters such as laser power, machining speed, and gas presser on Inconel 825 plates, both linear and nonlinear. Statistical Analysis: Preliminary trials were conducted by changing the process parameters in order to design a process parameter window. Findings: The design matrix has been developed with L9 experiments, and the corresponding outputs and responses, such as kerf width and surface roughness, were measured and recorded. Applications: The responses have been used to measure the Ra and kerf values of all the specimens after being cut by LBM. Improvements: ANOVA identifies the influencing process parameters on machining Inconel 825 output responses, namely kerf width and surface roughness.

Determining the optimal laser cutting conditions for simultaneous improvement of multiple cut quality characteristics is of great importance. The aim of the present research is to simultaneously optimise three cut quality characteristics such as surface roughness, kerf taper angle and burr height in CO 2 laser cutting of stainless steel. The laser cutting experiment was conducted based on Taguchi's experimental design using L 27 experimental plan by varying four parameters such as laser power, cutting speed, assist gas pressure and focus position at three levels. Using the obtained experimental results three mathematical models for the prediction of cut quality characteristics were developed using artificial neural networks (ANNs). The developed response models for cut quality characteristics were taken as objective functions for the multi-objective optimisation based on the genetic algorithm. The obtained optimal solution sets were used to generate 2-D and 3-D Pareto fronts. The overall improvement of about 16% was registered in multiple cut quality characteristics.

The electric discharge machining (EDM) is one of the most up-to-date non-traditional machining processes, based on thermo-electric energy between the work piece and an electrode (tool). In this machining method, the material is removed electro thermally by a series of consecutive separate discharges between two electrically conductive materials (electrode and work piece). The performance of the machining process depends on the material, design and manufacturing method of the electrodes. Generally, the machine maker uses the average work piece and electrode materials to establish the EDM parameter settings. The current study paying attention on the effect of Copper and Brass tools on material removal rate (MRR) for AISI (American Iron Steel Institute) D2 tool steel by using DieSinker EDM. The current was varied from 4 to 10 amp, the electrical voltage and flushing pressure were constant, the MRR for copper electrode was in the range of 4.8923 -21.9580 mm/min whereas the range of MRR ...

Abrasive waterjet turning is new technology to machine cylindrical or axisymmetric parts from hard to machine materials. One of the problems of waterjet turning is that the real depth of cut usually is not equal with the adjusted radial depth of cut. Aim of the paper is to develop a mathematical method for determining the real depth of turning. This method is based on the equality of effecting time of the jet at turning and simple kerfing test accomplished by abrasive waterjet.

Light Amplification by Stimulated Emission of Radiation (laser) is among the fastest growing technologies in the engineering world and has a vast range of applications. It involves focusing photons of lights on a single spot of a workpiece with considerable accuracy, so as to transfer energy into the workpiece in a measure that is adequate to melt or achieve a particular material process. The technology is extremely broad, hence this review will focus on using laser for cutting applications which is one of the most popular, recently developed and emerging laser material processing techniques. This review utilizes relevant and recent literature to discuss material cutting by laser, the attributes of laser cutting, laser cutting parameters optimization as well as the trends in development of the process.

OMAX Corporation Peter H.-T. Liu, Sr. Scientist 21409 72 Avenue South Kent, WA 98032 Email: peter.liu@omax.com Phone: 253-872-2300 x140 MIT, Alex Slocum, Professor, Mechanical Engineering Department 77 Massachusetts Avenue, Cambridge, MA 02139-4307 Email: slocum@mit.edu Phone: 617-253-0012 Boeing Company Barton W. Moenster, Director Advanced Manufacturing RD MS: K2-03 Richland WA 99352 Email: darrell.herling@pnl.gov Phone: 509-375-6905 Oregon State University, Microproducts Breakthrough Institution (MBI), Brian K. Paul, Director, Nano/Micro Fabrication Facility, 204 Rogers Hall, Corvallis, OR 97331 Email: brian.paul@oregonstate.edu Phone: 541-737-7320 Delphi Corporation, Energy and Chassis, Fuel Cell and Reformer Center Karl J. Haltiner, SOFC Stack Team Leader Mail Code: 146-HEN-575, 5500 West Henrietta Road, West Henrietta, NY 14586-9701, Email: karl.j.haltiner@delphi.com, Phone: 585-359-6765

The aim of this research is to develop a laser cutting process model that can predict the relationship between the process input parameters and resultant surface roughness; kerf width characteristics. The research conduct is based on the Design of Experiment (DOE) analysis. Response Surface Methodology (RSM) is used in this research, it is one of the most practical and most effective techniques to develop a process model. Even though RSM has been used for the optimisation of the laser process, published RSM modelling work on the application of laser cutting process on cutting material is lacking. This research investigates laser cutting stainless steel to be best the circumstances laser cutting using RSM process. The input parameters evaluated are gas pressure, power supply and cutting speed, the output responses being kerf width, surface roughness. The laser cutting process is one of the widely used techniques to cut thickness material for various applications such as fiber, steel ...

Light Amplification by Stimulated Emission of Radiation (laser) is among the fastest growing technologies in the engineering world and has a vast range of applications. It involves focusing photons of lights on a single spot of a workpiece with considerable accuracy, so as to transfer energy into the workpiece in a measure that is adequate to melt or achieve a particular material process. The technology is extremely broad, hence this review will focus on using laser for cutting applications which is one of the most popular, recently developed and emerging laser material processing techniques. This review utilizes relevant and recent literature to discuss material cutting by laser, the attributes of laser cutting, laser cutting parameters optimization as well as the trends in development of the process.

This paper aims to highlight the influence of working regime parameters (flow of a water-abrasive cutting speed, grain size abrasive) on the surface quality obtained waterjet cutting and abrasive. It also highlights how theoretical research practice validated by cutting through the proposed method. The experimental program introduces a local Abrasive can reduce the cost of processing and which establishes the optimal processing regime. Depending on the analyzed parameters are calculated and the cost of processing with the use of two grades of abrasive: garnet and quartz sand.

In this paper, an erosion-based model for abrasive waterjet (AWJ) turning process is presented. By using modified Hashish erosion model, the volume of material removed by impacting of abrasive particles to surface of the rotating cylindrical specimen is estimated and radius reduction at each rotation is calculated. Different to previous works, the proposed model considers the continuous change in local impact angle due to change in workpiece diameter, axial traverse rate of the jet, the abrasive particle roundness and density. The accuracy of the proposed model is examined by experimental tests under various traverse rates. The final diameters estimated by the proposed model are in good accordance with experiments.

High-pressure water jet machining is characterized by wide possibilities of cutting diverse materials together with multi-layer materials with dissimilar properties, accurate cutting complex profiles, as well as conducting them in uncommon conditions, especially in cases of thick materials. An additional advantage of water jet technology is its environmental friendliness. This paper presents tests of the cutting performance of tool steel with the use of an abrasive water jet (AWJ). The state-of-the-art has shown insufficient scientific evidence in AWJ tool steels cutting using recycled abrasive materials. Therefore, the main motivation for this paper was to carry out research from an environment aspect. The reuse of abrasives and the use of recycled materials have immense potential to reduce processing costs while remaining environmentally friendly. The RSM method was used for modeling and optimization. A response surface design (RSM) is a package of an advanced design-of-experiment...

This paper presents the results of experimental research on the behavior of tool-electrodes made of copper, brass, aluminum and graphite by applying pulsed electrical discharges. The electrodes applied to the formation of the surface layers are made of conductive materials subjected to different energetic modes during the experimental investigations. The authors studied the effects that appear between the base electrodes (anode and cathode) varying the polarity and charging voltage of the capacitor while the other regimes remain constant (gap, DEI frequency, capacity and time).

The CMS experiment will change it's silicon tracker completely during phase-II upgrade. There is need to develop light and high precision and durable mechanical structure for silicon modules. The prime purpose of this should also be reducing material in the silicon tracker detector. The group at IIT Madras is involved in R&D of production of this structures. We have produced high precision bridge made of AL-CF material and carbon fiber stiffener.

 Using low levels of machining parameters (voltage, Ip and Ton) to achieve low EWR.  According to Factorial Design, model fits the data was 97.65% and 97.83% for 140 and 240 V, respectively.  M athematical relationship between the input parameters and EWR has been gained for correlating EWR. Electrical Discharge M achining process (EDM) is a nontraditional metal removal technique that uses thermal energy to erode the workpiece without generating any physical forces of cutting between the tool and the machining part. It is used to cutting of hard and electrical conductivity materials and product intricate shapes of products. The aim of this work is to study the effect of changing voltage values on electrode wear rate (EWR). The machining parameters includes voltage (V), peak current (Ip), pulse duration (Ton) and finally, pulse interval (Toff). The results show that the EWR was increase with rising in voltage, peak current and pulse duration values but when the pulse interval value rises, the electrode wear rate reduce. The best (EWR) value was (0.093507) mm3/min that obtained at voltage (140) V, Ip (12) A, Ton (400) µs and Toff (12) µs.

To determine if Madhav Institute of Technology and science, Gwalior has a viable option for implementation of a 1kW Solar PV Project on a standalone mode in terms of technical feasibility and cost effectiveness and its implementation to meet the electricity demand. The performance of off-grid solar PV system is evaluated in six rooms as self-sustainable. After thorough study of the past work it is felt that further research can be extended in the area by taking different items of local importance. It is further decided to check the performance of off-grid solar PV system and make the six faculty's room selfsustainable and net Zero. The purpose of this work is to create and analyze an experiment of an estimate power for enhancing system performance and to assist in integrating into the faculty building's power grid system. The results findings might be used as a reference for comparable applications and as a tool for academics and engineers to assess the setup, behavior, and operation of a rooftop PV conversion system. The results of this experiment are a reference study for mechanical wing of college campuses and towns on migrating to a smart, green, and clean energy building idea. "Smart Grid" is the term used here.

Abrasive water-jet manufacturing process can shape a lot of materials ranging from metals to glasses. It has a lot of advantages, as its low cutting forces, but remains quite difficult to control. Indeed, the process is leaded by the abrasive particle trajectories which depends on the water static pressure and many other parameters. The impact pressure on the work-piece is commonly modeled by a two Gaussian fit sum which are representative of the particles velocity distribution and the granulometry respectively. Today no studies based on discrete elements take into account the mixing chamber and the focal canon which are the two main steps of the abrasive water-jet tool constitution. In this preliminary work we propose to model the flow through the focal canon until the target impact by an original numeric granular approach. The Non-Smooth Contact Dynamics is an efficient method on a large range of simulation domains. In our case, we consider the water phase and the abrasive phase as two collections of distinct polydisperse elements. The masses are corrected and the contact interaction laws are adjusted to account for an equivalent fluid which similar mechanical properties. These two phases are mixed in a chamber and focalised through the canon, knowing water static pressure and abrasive mass rate. After the canon end the abrasive water-jet evolves in air and thus decelerates by friction. The tool-fluid adapts its geometric configuration from this kinetic energy decrease and impacts a target plane located at a known distance from the canon. Such a model is built on some classic process parameters as the water static pressure, the abrasive mass rate or the work-piece vs. canon distance, but it also naturally takes into account finer mechanical parameters as the abrasive granulometry or friction dissipation. Simulations gives interesting results of impact pressure distribution on the target work-piece with dynamic data of all the collection particles. More generally, this work final aim is to link elemental particle damage studies with a macroscopic wear prediction law.

Lauren Barnes, Katelynn Huneycutt, Elita Lobo, Nick Mazzoleni, Jenna McDanold, Richard Moore, Aprajita Singh, Jerome Troy, and Thomas Tu New Jersey Institute of Technology University of Maryland, Baltimore County University of Massachusetts, Amherst North Carolina State University Rochester Institute of Technology University of Texas, Dallas University of Delaware University of California, Los Angeles

This article presents the identification of the influence of the effects and interactions of the machining parameters (EDM) of the machine (EROTECH basic 450) in order to model the material removal rate (MRR), the tool wear rate (TWR) and the roughness of the part (Ra). We look at all the machining parameters and collect the effects by the design of experiments method. The modeling carried out is thus carried out by the response surfaces method (RSM). We use the statistical method (ANOVA) analysis of variance to approve the robustness of the models and to verify that they are statistically significant. The Taguchi method was implemented to formulate mathematical models to predict EDM machining parameters. The prediction of responses by empirical models is compared with experimental validation tests and the results are satisfactory.

Abrasive-waterjets (AWJs) are formed by mixing high-pressure (up to 400 MPa) waterjets (0.1 to 1 mm in diameter) with abrasive particles in mixing tubes with typical 1/d ratios of 50 to 100. The pressure of the waterjet influences the overall performance of the abrasive-waterjet cutting system through operational and phenomenological effects. Higher pressures result in lower hydraulic efficiency, more frequent maintenance, high wear rates of mixing tubes, and fragmentation of particles before they exit the nozzle. However, with high pressures, deeper cuts can be obtained and higher traverse speeds can be used. Consequently, the hydraulic power is best utilized at an optimum pressure, which is a function of all other parameters as well as the application criteria. This paper presents data and analyses on the effect of pressure on nozzle operational characteristics, i.e., jet spreading characteristics, abrasive particle fragmentation, suction capability, wear of mixing tubes, and mixi...

In today's competitive environment components having high dimensional accuracy and better functional performance are highly demanded. Abrasive Flow Machining is one of the vital non-conventional techniques used for the finishing of complex geometries which is not easy with other conventional processes. It provides finishing up to nano level. During the finishing, parameters affecting the system efficiency are very important to identify to improve the productivity of the system. This paper discusses a newly developed technique i.e spark assisted Abrasive Flow machining, which uses the spark energy to improve the material removal and providing better surface finish and also parameters such as rotational speed of the electrode, duty cycle and current were optimized for the better surface finish using Taguchi L 9 OA.

Design of Experiment commonly referred to as DOE is one of the extensively used methods for experimental study of many processes in engineering. It is a statistical approach in which a mathematical model is developed through experimental runs. DOE provides us the opportunity to optimize and predict possible output based on the parameters setting. In this study, a review is done on DOE techniques that have been employed for laser beam process optimization by other researches. This study predominantly focuses on the usage of response surface methodology, Taguchi's method and factorial design in laser beam machining. A deduction is made to illustrate the significance of machining parameters to responses. Index Term-Design of experiment, mathematical model, response surface methodology, Taguchi method, factorial design.

Laser cutting of nickel-based superalloy sheets, having wide applications in aircraft and rocket industries, is important from the quality of cut point of view. Keeping this in view, a hybrid approach of Taguchi method (TM) and principal component analysis (PCA) has been applied for multi-objective optimization (MOO) of pulsed Nd:YAG laser beam cutting (LBC) of nickel-based superalloy (SUPERNI 718) sheet to achieve better cut qualities within existing resources. The three-quality characteristics kerf width, kerf deviation (along the length of cut), and kerf taper have been considered for simultaneous optimization. The input parameters considered are assist gas pressure, pulse width, pulse frequency, and cutting speed. Initially, single-objective optimization has been performed using TM and then the signal-to-noise (S/N) ratios obtained from TM have been further used in PCA for multi-objective optimization. The results of MOO include the prediction of optimum input parameter level and their relative significance on multiple quality characteristics (MQC). The responses at predicted optimum parameter level are in good agreement with the results of confirmation experiments conducted for verification tests.

The economics of cutting at 600 MPA using abrasive waterjets is discussed in this paper. The operating cost of the AWJ process consists mainly of the costs of abrasives, nozzle wear, utility, and maintenance of equipment. The cost per unit length of material (specific cost) is determined based on the cutting speed. It was found that increasing the pressure at fixed power or fixed orifice size will increase the cutting speed. In the first case, this increase is due to increased jet power density which is more suitable for thin materials. In the second case, the cutting speed increase is due to increase in the power and the power density, and thus thicket materials can be cut efficiently. The main advantage of increasing pressure in either case is reducing the abrasive consumption per unite time or length of cut. Even if the pump maintenance cost increases by a factor of 2, the cost per unit length will decrease for most common parameters. The reduction in abrasive consumption and the...

The paper deals with the verification of suitability of water jet and abrasive water jet application for the disintegration of rotating samples of wood plastic composites (WPCs) with diameter d=36 mm. The influence of selected technological factors (traverse speed of cutting head v [mm/ min] and size of abrasive particles [MESH]) on the topography of resulting surfaces has in particular been studied. Surface topography and quality have been assessed using the methods of optical and confocal microscopy and optical profilometry. The presented procedures and results of experiments demonstrate the technology of abrasive water jet as an appropriate tool for the rough machining of WPCs and similar composite materials. In addition, the application of this technology can effectively solve the problem of the melting of the polymer matrix and its subsequent sticking to the functional parts of a cutting tool resulting from conventional turning.

This paper shows the impact of mixing water and abrasives in water jet cutting process on the quality of the machined surface. The tests werw done with polymer material SIPAS, where the influence of cutting parameters was researched (cutting pressure, cutting feed and abrasive mass flow). The surface roughness was measured on several zones, regarding the depth of materials, because the roughness is increase with the material thickness.

This paper presents a model to predict the depth of penetration in polycrystalline ceramic material cut by abrasive waterjet. The proposed model considered the interaction of cylindrical jet with target material in upper region and neglected the role of threshold velocity in lower region. The results predicted with the proposed model are validated with the experimental results obtained with Silicon Carbide (SiC) blocks.

Axis gantry robots and 6-axis articulated arm robots have been used with plain waterjets for many applications especially in the automotive industry. This paper is on extending the use of these robots to abrasive waterjets and for a much wider range of applications. The integration of the abrasive waterjet process on robotic arms has been successfully developed to address the end effector, supply of high pressure water and abrasives to the cutting head, and operational safety. Off line programming, calibration, and inspection are discussed. Advanced software packages typically used in the aerospace industry have been successfully adapted. The need for enhanced accuracy performance using first article inspection results is discussed. A few case studies are presented in this paper addressing composite trimming for wing skins used in aircraft and wind turbines and for stone cutting with hybrid processes. It was found that 6-axis robot arms can eas- ily be implemented when moderate accu...

Design of Experiment commonly referred to as DOE is one of the extensively used methods for experimental study of many processes in engineering. It is a statistical approach in which a mathematical model is developed through experimental runs. DOE provides us the opportunity to optimize and predict possible output based on the parameters setting. In this study, a review is done on DOE techniques that have been employed for laser beam process optimization by other researches. This study predominantly focuses on the usage of response surface methodology, Taguchi's method and factorial design in laser beam machining. A deduction is made to illustrate the significance of machining parameters to responses. Index Term-Design of experiment, mathematical model, response surface methodology, Taguchi method, factorial design.

Abstract-Design of experiment uses a series of structured analytic method to investigate the relation between parameters and the responses. The particular technique used in this study is response surface methodology. Using the DOE approach, a mathematical based model was developed through regression analysis to study the response prediction. It is found that for kerf width the cutting speed plays an important role. Only a high cutting speed can produce good kerf width. When considering the interaction between the parameters, duty cycle directly depends on frequency where a high duty cycle is needed for high frequency cutting and vice versa to obtain a good kerf width.

Design of Experiment commonly referred to as DOE is one of the extensively used methods for experimental study of many processes in engineering. It is a statistical approach in which a mathematical model is developed through experimental runs. DOE provides us the opportunity to optimize and predict possible output based on the parameters setting. In this study, a review is done on DOE techniques that have been employed for laser beam process optimization by other researches. This study predominantly focuses on the usage of response surface methodology, Taguchi's method and factorial design in laser beam machining. A deduction is made to illustrate the significance of machining parameters to responses. Index Term-Design of experiment, mathematical model, response surface methodology, Taguchi method, factorial design.

Abrasive water-jet manufacturing process can shape a lot of materials ranging from metals to glasses. It has a lot of advantages, as its low cutting forces, but remains quite difficult to control. Indeed, the process is leaded by the abrasive particle trajectories which depends on the water static pressure and many other parameters. The impact pressure on the work-piece is commonly modeled by a two Gaussian fit sum which are representative of the particles velocity distribution and the granulometry respectively. Today no studies based on discrete elements take into account the mixing chamber and the focal canon which are the two main steps of the abrasive water-jet tool constitution. In this preliminary work we propose to model the flow through the focal canon until the target impact by an original numeric granular approach. The Non-Smooth Contact Dynamics is an efficient method on a large range of simulation domains. In our case, we consider the water phase and the abrasive phase as two collections of distinct polydisperse elements. The masses are corrected and the contact interaction laws are adjusted to account for an equivalent fluid which similar mechanical properties. These two phases are mixed in a chamber and focalised through the canon, knowing water static pressure and abrasive mass rate. After the canon end the abrasive water-jet evolves in air and thus decelerates by friction. The tool-fluid adapts its geometric configuration from this kinetic energy decrease and impacts a target plane located at a known distance from the canon. Such a model is built on some classic process parameters as the water static pressure, the abrasive mass rate or the work-piece vs. canon distance, but it also naturally takes into account finer mechanical parameters as the abrasive granulometry or friction dissipation. Simulations gives interesting results of impact pressure distribution on the target work-piece with dynamic data of all the collection particles. More generally, this work final aim is to link elemental particle damage studies with a macroscopic wear prediction law.

The aim of this research is to develop a laser cutting process model that can predict the relationship between the process input parameters and resultant surface roughness; kerf width characteristics. The research conduct is based on the Design of Experiment (DOE) analysis. Response Surface Methodology (RSM) is used in this research, it is one of the most practical and most effective techniques to develop a process model. Even though RSM has been used for the optimisation of the laser process, published RSM modelling work on the application of laser cutting process on cutting material is lacking. This research investigates laser cutting stainless steel to be best the circumstances laser cutting using RSM process. The input parameters evaluated are gas pressure, power supply and cutting speed, the output responses being kerf width, surface roughness. The laser cutting process is one of the widely used techniques to cut thickness material for various applications such as fiber, steel ...

Experiments were performed based on response surface methodology (RSM) to investigate the process parameters effect on the features of hole geometry. Cutting speed (of 500-1000 mm/min), laser power (of 2000-4000 W), frequency (of 800-2000 Hz), duty cycle (of 75-95%), and gas pressure (of 0.05-0.15 bar) were considered as variable parameters. Deviation in the dimension of entrance and exit holes, heat affected zone (HAZ) on the upper & lower edge, and roughness were the output to analyse the cutting quality of 14 mm thick normal and heat-treated (HT) EN-31 die steel using 4 kW CO2 laser. For untreated plate, minimum taper angle was achieved with low cutting speed, higher laser power, and gas pressure. Higher cutting speed, low laser power, and higher gas pressure result in the minimum HAZ. For the HT plate, the mid-range of parameters results in the minimum taper angle and HAZ. An optimised model was developed, and the confirmatory test gives roughness up to 0.27 microns and it shows...

Laser Induced Micro-machining (LIMM) uses a focused high power laser beam to remove volume of material by using the phenomenon of ablation. In comparison with mechanical micro-machining operations, it offers better machining efficiency in terms of accurate work or feature geometry, efficient debris removal, and better surface morphology. This is due to the fact that laser can be very precisely focused onto the work piece and results into the removal of material from the focal volume only. In this present work, an experimental study on manufacturing of micro-channels of width 150 µm on mild steel, by focusing the second harmonic of a high power Q-switched Nd:YAG laser, has been presented. Initially two sets of experiments have been carried out by varying the scan speed of the sample. The laser energy was kept constant in both the cases. The work specimen was characterized for dimensional accuracy and shape of the channel generated. These preliminary results are encouraging to manufac...

The applications of Taguchi method and RSM to modelling the laser parameters when machining industrial PVC foams is presented. The influence of cutting speed, laser power, frequency, duty cycle, and gas pressure on kerf width has been considered in this investigation according to Taguchi method using a standard orthogonal array L27 and RSM using a central composite design. Taguchi technique as well as 3D surface plot of RSM revealed that the cutting speed is the most significant factor in minimizing kerf width followed by laser power and etc. A predictive mathematical model was then developed through a regression analysis in both analytical tools to study the response. Though both the techniques predicted near values of average error, the RSM technique seems to be more promising in predicting the response via mathematical modelling over the Taguchi technique.

Micro EDM process is one of the micro- machining processes. It can be used to machine micro features and makes a micro parts. There is a huge demand in the production of microstructures by a non-traditional method
which known as Micro-EDM. Micro-EDM process is based on the thermo electric energy between the workpiece and an electrode. Micro-EDM is a newly developed method to produce micro-parts which in the range of
50 μm -100 μm. Micro-EDM is an efficient machining process for the fabrication of a micro-metal hole with various advantages resulting from its characteristics of non-contact and thermal process. A pulse discharges
occur in a small gap between the work piece and the electrode and at the same time removes the unwanted material from the parent metal through the process of melting and vaporization. This paper describes the
importance, parameters, principle, difference between Macro and micro EDM, applications and advantages of μ- EDM and discuss about the literature reviews based on performance measure in micro- EDMP process.

Electrical discharge machining (EDM) process is convert electrical energy into heat energy between the work piece and tool electrode in the presence of dielectric fluid like, EDM oil, to process conductive difficult-to-machine materials. EDM process is has been applicable in the machining of hard, brittle and all kinds of electric conductive materials. This process widely used for produces die making, mould making, complex shapes, deep holes and other geometrical shapes as per desire. Inconel 600 super alloy materials widely used in various types of industries such as: aerospace, aircraft, nuclear, food processing, pulp manufacturing, automobiles industry etc. In this study, investigations on the effect of process parameters on machining of Inconel 600 super alloy material. Tungsten carbide material used as tool electrode and EDM oil used as dielectric fluid. The effects of input process parameters such as pulse-on-time, peak current and gap voltage on performance measure material removal rate was investigated using Taguchi method. MRR is lineally increases with the increase in peak current during the EDM process. MRR is increases with the increase in gap voltage. Initially MRR increases with increase in pulse on time then decreases with the increase of pulse on time.

Electrical discharge machining (EDM) is a non-traditional machining technique that is commonly employed on hard materials. The fact that EDM can cut any conductive material, independently of its hardness, has made it popular. EDM is extensively used to shape or create advanced technological materials which are used in extreme conditions. The effects of input parameters on the effective machining of Inconel 600 superalloy was investigated in this study. The tool electrode was made of Tungsten Carbide (WC), and the dielectric fluid was EDM oil. The Taguchi method was used to investigate the effects of control factors including pulse-on-time (T on), peak current (I p), and gap voltage (V g) on the performance criterion TWR. Using an orthogonal array (OA) L9, the research were carried out at three levels. The EDM performance aspects were investigated using the signal-to-noise ratio and ANOVA. The Taguchi technique was used to optimize the input and output parameters using the statistical software MINITAB-17. During the EDM process, TWR grows somewhat linearly with increasing I p. TWR reduces as V g increases, then increases as V g increases. TWR increases with increasing T on and then drops with increasing T on. The tool wear rate is lowest at the first level of Ip, the second level of Vg, and the third level of Ton. ANOVA revealed that I p , V g , and T on all had a significant influence on TWR. Obtained optimum input variables value for tool wear rate are I p (30 A), V g (94 V), and T on (150 s). The predicted ideal range of TWR at 95% confidence level was confirmed by conducting confirmation experiments, wherein the TWR was achieved as 0.551 mm 3 /min. To validate Taguchi's optimization approach, confirmation tests were performed using optimal values of input parameters.

This paper investigates the influence of jet traverse speed and water jet pressure of abrasive water jet machining (AWJM) on the magnesium-based metal matrix nanocomposites (Mg-MMNC) reinforced with 50 nm (average particle size) 0.66 and 1.11 wt.% Al2O3.The extent of grooving caused by abrasive particle and irregularities in AWJ machined surface with respect to traverse speed and cutting depth was investigated. The nanoindentation results hows softening of the material defended by higher reinforcement content nanocomposite due to presence of sufficient amount of nanoparticles protecting the surface from being damaged. The values of selected amplitude parameters viz. average roughness (Ra), maximum height of peak (Rp), maximum depth of valleys (Rv) presenting the comparatively smooth surface finish in 1.11 wt.% reinforced composite at high (500 mm/min) speed. Moreover, the high water pressure AWJM produces the better surface quality due to sufficient material removal and proper clean...

This paper contains investigations on the behavior of five artificial rocklike materials subjected to abrasive water jet cutting. The influence of the test parameters, i.e. applied pump pressure, traverse rate and abrasive mass flow rate was investigated, as well as the influence of several material parameters, e.g. compressive strength, Young's modulus, absorbed fracture energy and crack velocity. For the test parameters, it is found that two sets of critical parameters exist. First, there are minimum threshold values which must be exceeded to initiate the material destruction process. Second, critical values for the test parameters exist which should not be exceeded in order to ensure an effective cutting process. Based on statistical calculations it is found that the crack velocities of the materials have the most significant effect on the cutting process. The crack velocity of the material influences the depth of the cut, specific energy, and threshold parameters of the cutting process.