Surface Finish

A wide variety of industrial processes involve the transfer of heat energy between fluids in process equipment. As a result of this energy exchange unwanted deposits accumulate on the process surfaces causing a resistance to energy transfer. These deposits reduce the heat recovery and can restrict fluid flow in the exchanger by narrowing the flow area. Prevention and control of fouling is costly and time consuming. In many situations, fouling can be reduced but not necessarily eliminated. Fouling is a major unresolved problem in heat transfer. In general, the heat exchangers evaluated in this study were exposed to untreated lake water for typical conditions. After the prescribed time period the exchangers were taken off line and evaluated. Conclusions and observations regarding fouling of brazed heat exchangers, exposed to once-through lake water, are presented here. Transient observations and photographs of the exchanger surfaces are given. Results are presented that compare these heat exchangers to test plates, also exposed to lake water. The progressive change of surface appearance with increasing immersion times is presented.

The objective of this paper is to study the effect of different process parameter of wire electrical discharge machine (WEDM) process on the performance measures such as material removal rate (MRR), surface roughness, dimensional accuracy and kerf width. It is necessary to evaluate the factors that affect the productivity and efficiency of WEDM process. It will directly contribute to increase cutting speed and dimensional accuracy.

Burnishing is a chipless finishing method, which employs a rolling tool, pressed against the workpiece, in order to achieve plastic deformation of the surface layer. Recent developments made possible burnishing of heat-treated steel components up to 65 HRC. Features of burnishing include a good roughness (comparable to grinding), as well as improvement of mechanical characteristics of the surface (fatigue strength, corrosion resistance, and bearing ratio), due to implementation of compressive stresses into the surface layer. This paper will present influences of certain burnishing parameters upon roughness, for a hardened steel component (64 HRC).

Drilling of CFRP/Al or CFRP/Ti, or Al/CFRP/Ti is a challenge to manufacturing engineers. Drilling of CFRP is manageable but the minute drill hits the Al or Ti, those hot and continuous chips destroy the hole. Few studies are carried out in this aspect; CFRP/Al is not reported till date. It is important to select right process parameters when drilling multimaterial stack since each material in the stack requires a different set of machining parameters. Hence, Drilling trials have been carried out in carbon-fibre reinforced plastics (CFRP)/aluminium (Grade 2024) stack without coolant, with plain carbide (K20) drills of various diameters to choose optimum process parameters. The parametric influences on thrust force, torque as well as surface finish were experimentally evaluated. The experimental results show that the quality of holes can be improved by proper selection of cutting parameters. This is substantiated by monitoring thrust force, torque, surface finish, circularity and hole diameter. For the CFRP, the circularity is found to be around 6 lm at low feed rates, when the feed is increased the circularity increases to 25 lm. The wear tests carried out show that, during first 30 holes, thrust force in CFRP undergoes a more important increase (90%) than thrust force of aluminium (6%).

Investment casting is one of the oldest manufacturing processes, dating back thousands of years, in which molten metal is poured into an expendable ceramic mold. The mold is formed by using a wax pattern-a disposable piece in the shape of the desired part. The pattern is surrounded, or "invested", into ceramic slurry that hardens into the mold. Investment casting is often referred to as "lost-wax casting" because the wax pattern is melted out of the mold after it has been formed. Investment casting requires the use of a metal die, wax, ceramic slurry, furnace, molten metal, and any machines needed for sand-blasting, cutting, or grinding. In the present study, an attempt has been made to produce a wax blend which could offer minimum linear and volumetric shrinkage and better surface finish. Experiments were conducted with different types of waxes namely Paraffin wax, Bees wax, Carnabua wax and Microcrystalline wax by varying their proportions. In each case, properties of wax pattern like surface finish, percentage linear and volumetric shrinkage were determined. An attempt was made to find out the set of input parameters, which could offer a set of ideal properties ofthe wax blend, using Taguchi method. The set of input parameters suggested by Taguchi method was experimentally verified and found to offer the set of desired optimal properties of the wax blend pattern.

Purpose: This study evaluated the effect of artificial saliva storage on the hardness, crack length, and fracture toughness of a glazed, polished, and bleached hydrothermal low-fusing glass-ceramic (Duceram LFC). Materials and Methods: Forty ceramic discs were constructed. The discs were assigned to four groups (n = 10) according to their surface finish: Gp1-Autoglaze, Gp2-Autoglaze/ground/diamond-polished, Gp3-Overglaze, Gp4-Overglaze/ground/diamond-polished. Each group was further divided into two subgroups forming eight total subgroups (n = 5). Subgroup A was unbleached; Subgroup B was bleached. Testing was performed before and after 21 days of artificial saliva storage. Data were presented as means and standard deviation (SD). ANOVA was used, along with Duncan's post hoc test for pairwise comparison between the means when ANOVA test was found significant (p ≤ 0.05). Results: Surface treatments such as glazing, polishing, and bleaching, saliva storage, and the interaction between these variables had a statistically significant effect on mean values of microhardness, crack length, and fracture toughness of the specimens. There was a statistically significant increase in microhardness and fracture toughness mean values, while crack length values decreased after saliva storage. Polished specimens recorded the smallest crack lengths and fracture toughness, and highest hardness values before and after saliva storage. No difference in fracture toughness values was evident between glazed and polished specimens. Mean crack lengths decreased after saliva storage in all the tested specimens. Hardness values increased after saliva storage. The autoglazed group showed significantly higher fracture toughness, lower crack length, and microhardness than the overglazed group. Conclusions: Surface finishing procedures and artificial saliva storage had a statistically significant effect on mean values of microhardness, crack length, and fracture toughness. This in vitro study suggests that fracture toughness of ceramics may be affected by different surface treatments such as glazing, polishing, bleaching, or a combination; however, in this study Duceram LFC proved its self-healing property after 3-week storage in artificial saliva.

The market for freeform and high quality microdies and moulds made of steel is predicted to experience a phenomenal growth in line with the demand for microsystems. However, micromachining of hardened steel is a challenge due to unpredictable tool life and likely differences in process mechanism compared to macro-scale machining. This paper presents an investigation of the size effect in micromilling of H13 hardened tool steel. In this case, the size effect in micromilling hardened tool steel was observed by studying the effect of the ratio of undeformed chip thickness to the cutting edge radius on process performance. The paper explores how this ratio drives the specific cutting force, surface finish and burr formation in micro-scale machining. In addition, the effect of different microend mill geometry on product quality was explored. The paper provides a valuable insight into optimum micro-scale machining conditions for obtaining the best surface finish and minimizing burr size.

In the present paper an experimental study to investigate the turning of hardened AISI 6150 heat treatable steel using polycrystalline boron nitride (PCBN) tools is presented. Design and analysis of computer experiments (DACE) was used to generate a comprehensive empirical description of the process characteristics. More specific, the effects of the parameters cutting speed, feed and depth of cut on the objectives tool wear, tool life, tool life volume, surface finish and process forces were modeled. A total of 157 experiments was carried out with 15 different parameter-value sets to obtain the training data for modeling the progression of the objectives versus cutting path length and width of flank wear land. Pseudo-3D surface plots are generated to visualize the effects and interactions. Unexpected effects of depth of cut on tool life were found and the validity of conclusions about the effect of cutting speed on tool wear and tool life are discussed. Moreover, qualitative explanations for some of the observed effects are presented.

This paper focus on monitoring of surface roughness and cutting forces while machining on two different grade stainless steels under dry and mist conditions. Stainless steels like AISI 304 and AISI 316L are considered for study. Process variables like workpiece speed, tool feed and depth of cut are taken for experimentation on CNC lathe. Responses like surface roughness, power consumption and cutting forces are predicted while machining on the two different stainless grades under dry and mist. Taguchi design of experiments is considered for experimental design. Signal-to-noise ratio of the responses are used for determining individual optimization, while Analysis of Variance is used for knowing significant effect of process variables over the generated responses. This paper shows novelty of using power consumption for calculating cutting forces and also comparisons of two different stainless steel grades simultaneously under dry and mist conditions. In addition, comparison of AISI 304 material with two different diameters is also studied.

From the Neolithic up to the present, people have used various methods to improve the surface of ceramic objects. In this study, we look specifically at smoothing and pattern burnishing of ceramics produced today by traditional methods. Optical microscopy and SEM show specific surface changes. Smoothing results in an irregular surface, which causes diffused reflection of light. Burnishing produces an even and compact surface, which causes specular reflection and lustre. The results can be used to infer methods of surface treatment employed by ancient peoples as well as to help identify the presence of ceramics production centres at archaeological sites.

An International Workshop on Metrology for X-ray and Neutron Optics, the first of its kind, was held on March 16-17, 2000, at the Advanced Photon Source at Argonne National Laboratory. Metrology specialists, beamline engineers and scientists, and vendors from around the world met to evaluate current metrology instrumentation and methods used to characterize the surface figure and finish off long grazing-incidence optics used in synchrotron radiation beamlines, and to consider future needs for synchrotron, free-electron laser, and neutron sources. This paper summarizes the discussions on mirror and metrology requirements for the current and next-generation X-ray sources. Some recommended strategies for the needs of the future are also given. # 2001 Published by Elsevier Science B.V.

Wire electrical discharge machining (WEDM) technology has been used widely in production, aerospace/aircraft, medical and virtually all areas of conductive material machining. Its complexity and stochastic nature have stimulated numerous attempts t~ model it accurately. This paper presents an attempt at modeling the process through Response Surface Methodology and Artificial Neural Networks. A response surface model based on a central composite rotatable experimental design, and a 4-16-3 size back-propagation neural network have been developed. The pulse-width, the time between two pulses, the wire mechanical tension and the injection set-point are selected as the factors (input parameters), whilst the cutting speed, the surface roughness and the :,urfr~ce waviness are the responses (output parameters). The two models are compared for goodness of fit. Verification experiments have been carried out to check the validity of the developed models. It is concluded that both model:~ provide accurate results for the process. © 1997 Elsevier Science S.A.

Surface finish is a prime factor for each and every machined product. Surface finish is an important factor in determining the satisfactory functioning of the machined components. A good surface finish improves the appearance, adhesion, corrosion resistance, wear resistance, hardness, modify electrical conductivity, remove burrs and other surface flaws, and controls the surface friction. Hence, the surface finish needs to be measured accurately to ensure the proper functionality of the machined component in the desired applications. Considering the importance of developing accurate and simple measurement techniques of surface finish, this work was undertaken to design a unique model which is enabled to measure surface roughness with the help of RGB values of the given images of the machined component using MATLAB. The objectives of the project include developing a model to classify the type of process the work piece has undergone and to develop a model to predict the cutting parameters of the machined work piece.

Wire-electro discharge machining (WEDM) has become an important non-traditional machining process, as it provides an effective solution for producing components made of difficult-to-machine materials like titanium, zirconium, etc., and intricate shapes, which are not possible by conventional machining methods. Due to large number of process parameters and responses lots of researchers have attempted to model this process. This paper reviews the research trends in WEDM on relation between different process pa-rameters, include pulse on time, pulse off time, servo voltage, peak current, dielectric flow rate, wire speed, wire tension on different process responses include material removal rate (MRR), surface roughness (Ra), sparking gap (Kerf width), wire lag (LAG) and wire wear ration (WWR) and surface integrity factors. Furthermore, different types of WEDM methods introduced and discussed. In ad-dition the paper highlights different modelling and optimization methods and discussed their advantage and disadvantage. The final part of the paper includes some recommendations about the trends for future WEDM researches.

The final machining (or finishing) of precision parts with high level of surface finish and close tolerance is making the application of magnetic abrasive finishing technology increasingly important. Magnetic abrasive flow finishing (MAFF) is a new abrasive finishing process combining the features of abrasive flow finishing (AFF) and magnetic abrasive finishing (MAF). MAFF provides a high level of surface finish and close tolerances for wide range of industrial application. This paper focuses on the modeling and simulation for the prediction of surface roughness on the workpiece surface finished by MAFF process. A finite element model is developed to find the magnetic potential distribution in the magnetic abrasive brush formed during finishing action and then it is used to evaluate machining pressure, surface finish and material removal. The simulation results are compared with the experimental results available in the literature. The simulated workpiece surface roughness shows features similar in nature to the experimental results.

In turning many key factors like, type of tool bit and its setting angle, machining conditions, type of material to be machined, spindle speed, cutting speed and feed rate etc., plays an important role. Out of all tool bit and cutting speed plays vital role. In this study, on lathe Machine Turning operation has been carried out for different Steel materials such as Mild Steel, EN-8, EN-31 and OHNS by maintaining constant depth of cut and feed by using DNMG 110404 carbide insert tool bit and then with High speed steel (HSS) tool bit at various cutting speeds 400, 800, 1200, 1600 rpm respectively. The surface roughness values have been compared for both the tool bits and the cutting force values have been analyzed for carbide insert tool bit. From the study the effectiveness of carbide insert tool bit has been noticed for steel materials at various cutting speeds in turning operation.

Efficient machining of advanced Ti-and Ni-based alloys, which are typically difficult-tomachine, is a challenge that needs to be addressed by the industry. During a typical machining operation of such alloys, high cutting forces imposed by a tool on the work-piece material lead to severe deformations in the process zone, along with high stresses, strains and temperatures in the material, eventually affecting the quality of finished work-piece.

Pumps are very important and very widespread energetic machines. They are used in all branches of industry. Pumps are also a major consumer of electricity and therefore their development is even more important. From theoretical through experimental development in the last decades, a quantity of research has focused on numerical analysis. These are used to optimize all kinds of characteristics, from energy and cavitation, to dynamic characteristics. At the beginning of Computational Fluid Dynamics (CFD) analyses were related to the physical model (potential flow, Euler equation, Navier-Stokes equations). Subsequently, a lot of research was carried out in the field of various turbulent models. With the launch of high performance multiprocessor computers, more and more time-dependent problems have been analysed. All the above mentioned research was carried out with numerical calculations on smooth surfaces. The fact is that in reality there is always some roughness on wet surfaces, depending on the material, the technology of production of certain parts of machines and finishing surface treatment. In the article, we give preliminary results of numerical analyses of centrifugal pumps, where the roughness of the walls was taken into account. The analyses were completed for different types of pumps, with different roughnesses and for different characteristics. First he effect of the roughness on the efficiency is shown, further the cavitation characteristics were analysed. The basic idea for research comes from the fact that there are still many cases where the matching of the results of the measurements and the results of numerical analyses are not perfect. One of the possible reasons can be the roughness of the walls.

Reçu le 8 janvier 2002; accepté le 11 avril 2002 Résumé L'application de la simulation numérique à l'usinage peut fournir un outil intéressant pour la prévision de l'apparition d'instabilités ainsi que pour la prédiction de l'état final de la surface usinée. Pour ce faire, l'interaction outil/pièce doit être étudiée avec finesse et un modèle de représentation mécanique suffisamment fidèle de l'ensemble Pièce/Outil/Machine doit être construit. La pièce est généralement la partie la plus variable du système : modification consécutive à l'usinage en cours ou plus simplement changement de pièce. L'élaboration du modèle associé à cette dernière dépend de ses caractéristiques propres (géométrie, masse et raideur) ainsi que de la nature des sollicitations qui lui sont appliquées. L'idéal est de construire un modèle suffisamment représentatif induisant des coûts numériques minimaux. Dans ce document, nous montrons l'importance du comportement dynamique de la pièce au cours d'un usinage par outil coupant (fraisage, tournage). Nous présentons différents modèles allant de la pièce non déformable (mais mobile), à la pièce déformable dont les caractéristiques dynamiques évoluent en cours d'usinage (cas des voiles minces). Les aspets techniques liés à la mise en place du modèle pièce déformable sont détaillés.

Several methods have been developed for the computerized generation of space-filling curves, but these curves have never been used for NC tool-path generation. The paper discusses the application of space-filling curves as tool paths for sculptured-surface machining. Tool paths that are space-filling curves, single-direction conventional paths, and 2-direction conventional paths are compared. The efficiency ratings of the paths require further testing, but the preliminary conclusions are favourable for space-filling curves.

Sintered tungsten carbide (WC) is an extremely hard and brittle material extensively used in tool manufacturing industries. However, the current cutting technologies for shaping this typical hard-tomachine material are still cost ineffective. In this study, polycrystalline diamond (PCD) tools are used to study the machinability of sintered WC ($15% Co) by applying the ultrasonic elliptical vibration cutting (UEVC) technique. Firstly, it presents the UEVC principle and the effects of speed ratio (i.e. the ratio of the nominal cutting speed to the maximum tool vibration speed in the cutting direction) on the tool-workpiece relative motion as the cutting speed greatly influences the UEVC performance. Then UEVC experiments are carried out to analyze the cutting force, tool-wear progression, chip formation and surface quality against the cutting time at different speed ratios. The results show that when the speed ratio decreases, the resultant cutting force and the tool flank wear decrease while the surface finish improves. Average surface roughness, R a , in a range between 0.030 and 0.050 mm is achieved at speed ratios less than 0.107. The experimental findings suggest that the commercial PCD tools can be used to machine sintered WC to achieve ultraprecision surface by applying the UEVC technique, which will be cost effective for miniature cutting technologies in future.

In the various fields of adhesive bonding mechanical surface roughening by abrasion is used to increase real surface area of the substrate. Mathematically, obtained surface roughness can be treated as realization of a Gauss process. If the correlation function of the profile is known, spectral density can be determined, also. It is shown that relation exist between abrasion tool surface profile and abraded surface profile of soft polymer material. Relations between correlation functions of both these surfaces are determined. During simulation of abraded profiles, it was determined that used simulation algorithm describes the abrasion process.

The aim of this study was to develop new soft contact lens (SCL) materials which would, after recommended and existing machining processes, improve surface roughness. Nanomaterials (fullerene, fullerol and methformin hydroxylate fullerene) were incorporated into commercial material for SCL (SL38) based on PHEMA, which were derived by the technology in the production lab of the company Soleko (Milan, Italy). Nanophotonic SCLs (SL38-A, SL38-B, SL38-C, respectively) were produced in the company Optix (Belgrade, Serbia) from the obtained materials. For the surface characterization of SCLs, AFM analysis and lacunarity method were performed. The results showed that for the SL38-B average roughness value is lower than those of SL38-A and SL38. The topography parameters of SL38-C were between the parameters of SL38-A and SL38-B. Lacunarity analysis of AFM images confirmed that SCLs surface state should belong to either group of adequate (slanted p-diagram) or inadequate (contorted p-diagram...

This paper outlines the fractional factorial approach of D.O.E. techniques (Taguchi& Response Surface Methodology) are applied to optimize turning process parameter in order to obtain better surface finish. The turning parameters evaluated are cutting speed, feed, and depth of cut. An orthogonal array, signal-to-noise (S/N) ratio, and Pareto analysis of variance (ANOVA) are employed to analyze the turning parameters. Main and interaction effects of process parameters on the quality characteristics (surface roughness) have been analyzed and the results shows that feed and interaction of cutting speed*depth affects the surface finish greatly. The parameter for getting better surface finish are cutting speed of 2400 rpm, feed rate 40 mm/min, and depth of cut 0.5 mm. Keywords: Design of experiment (D.O.E.); Taguchi method; Response Surface Methodology (R.S.M.); Optimization; Surface Finish.

Free-form surfaces are being used in a growing number of engineering applications, especially in injection molding of consumer products. Decreasing the manufacturing cost and time of these molds will improve the efficiency of manufacturing injection molded consumer products. This paper is motivated by the need for simple strategies to improve the quality of and decrease the time required to machine free-form surfaces. We present two methods to improve the surface finish of parts finished with ball-nose endmilling. In the first method the surface finish is improved by finding an optimal orientation angle for the workpiece relative to the machining axis. In the second method finish is improved by adaptively varying the step-size when using raster toolpaths. The adaptive variation is controlled by a user-defined finish improvement factor, where the spacing density is increased only if the improvement in surface finish is greater than the finish improvement factor. These methods are implemented using an analytical model of the workpiece surface finish based on the mean scallop height of the machined surface. Results from the analytical model are verified with machining experiments, and we show that the adaptive spacing strategy can improve the surface quality by more than 50% with a small increase in the toolpath length. To achieve a similar improvement in surface quality by uniformly decreasing the path spacing results in a much larger increase in the toolpath length. The strategies discussed in this paper allow process planners intuitive control over the toolpath layout and spacing and improve the efficiency of machining high quality parts.

Extrusion Honing (EH) is also known as Abrasive flow machining (AFM) is an effective method that is used to deburr, clean, polish, remove recast layer and micro cracks by flowing pressurized semisolid abrasive laden visco-elastic media over those surfaces. Inconel 625 is one of the most difficult-to-cut materials because of its low thermal diffusive property, high hardness and high strength at elevated temperature. In this paper, the influence of the process parameters on surface roughness is investigated on Inconel 625 material of square shape fabricated by Electric discharge machining (EDM). The processed surfaces were measured and analyzed with the help of surface roughness tester and Scanning Electron Microscope (SEM). Results show a significant improvement in surface finish and EH/AFM is capable of removing the micro cracks and recast layer.

We present a method of measure of the roughness of the paper based on the analysis of a speckle pattern on the surface. Images of speckle over the surface of paper are captured by means of a simple configuration using a laser, beam expander, and a camera chargecoupled device (CCD). Then we use the normalized covariance function of the fields, leaving the surface to find the roughness. We compare the results obtained with the results obtained with a confocal microscope and the Bendtsen method that is a standard of the paper industry. This method can be considered as a noncontact surface profiling method that can be used online. C 2011 Society of Photo-Optical Instrumentation Engineers (SPIE).

Details of the planned and actual schedules as well as date of receipt of results from the participants are shown in Table 2. The MRA states that the results should be sent within six weeks of completing the measurements. Table 2. Schedule of the comparison.

The accuracy of achieving required surface finish or surface roughness is of great importance in case of any mass production environment. Thus, understanding and recognizing the optimal process parameters for machining is the key to achieving the required surface roughness and gaining competitive advantage. This research is concerned with obtaining the optimal machining process parameters (cutting speed, depth of cut, feed) which will in turn effect in optimizing the surface roughness in turning glass fiber reinforced polymer (GFRP) matrix composite using coated carbide insert. To find the optimal machining process parameters Taguchi design method has been implemented. An L- 16 orthogonal array, signal to noise ratio and ANOVA have been implemented to analyze and understand various process parameters in deter- mining possible relationship with surface roughness. The optimum surface roughness value for this experiment is (3.664µm) which is obtained from Taguchi design method. The results from ANOVA conclude that feed is the most influential factor affecting the outcome having a contribution of (56.04%). And the contributions of depth of cut and cutting speed are separately in order of (17.94%) and (16.42%) respectively. This research provides optimal process parameters for any desired value of surface roughness which results in gaining a competitive edge over others in any mass production environment.

This paper presents an application of the Taguchi method parameter design to optimize the surface roughness, tool wear and cutting force by hard turning process. The Taguchi parameter design method is an efficient method in which response variable can be optimized, given various controls and using fewer experimental runs. Hard turning is the latest trend in all manufacturing industries and it is a profitable alternative to grinding. The hard turning removes unwanted material in a single cut rather than grinding in order to reduce process time, set up time, operating cost, surface roughness and to produce components economically. In the process of analyses, material having hardness between 54-58 was considered and three CBN cutting tool were used to conduct 18 tests. The response of surface roughness and flank wear taken for discussion and analyses. The experimental results show that there is a good agreement between surface roughness and flank wear both by equations and experiments by Taguchi method.

Pitting and micropitting are the two main gear rolling contact fatigue modes. It is widely accepted that micropitting will lead to pitting; however, the relationship between pitting and micropitting life needs further investigation. In this work, micropitting and pitting tests were performed on an FZG back-to-back test rig using standard FZG PT-C and GF-C gears. The gear tooth profile change due to micropitting and pitting damage was measured in situ in the gearbox using a profilometer after each test. The gear surface roughness parameters were calculated from the measured tooth profile. A Gaussian low pass filter with cut off length [Formula: see text] mm was applied to the measured tooth profile to obtain the waviness. The calculated roughness parameters and the obtained tooth profile with waviness for each test were imported into the KISSsoft software to calculate the contact stress and specific film thickness at the corresponding load stage. Experimental results show that smooth...

Non-minimal interactions in the pp-wave Einstein -Yang -Mills -Higgs (EYMH) model are shown to give rise to color cross-effects analogous to the magneto-electricity in the Maxwell theory. In order to illustrate the significance of these color cross-effects, we reconstruct the effective (associated, color and color-acoustic) metrics for the pp-wave non-minimal sevenparameter EYMH model with parallel gauge and scalar background fields. Then these metrics are used as hints for obtaining explicit exact solutions of the non-minimally extended Yang-Mills and Higgs equations for the test fields propagating in the vacuum interacting with curvature. The influence of the non-minimal coupling on the test particle motion is interpreted in terms of the so-called trapped surfaces, introduced in the Analog Gravity theory.

Turning is a versatile machining process that involves different cutting parameters and conditions. The surface finish is the vital design requirement as it is a key indicator of quality of the work piece. This work, presents the application of Quantum Inspired Evolutionary Algorithm (QIEA), that essentially exploits some principles of quantum mechanics such as Q-bits, superposition, quantum gate and quantum measurement, for the process optimization of plane turning. The QIEA estimated optimal cutting parameters i.e., cutting speed, feed rate, tool nose radius and depth of cut of plane turning for improved surface finish within the operating conditions. The results are compared with real coded genetic algorithm (RCGA) and differential evolution algorithm (DEA). The results obtained by Quantum Inspired Evolutionary Algorithm are better than those reported with RCGA and are comparable to those of DEA.

Wire-electro discharge machining (WEDM) has become an important non-traditional machining process, as it provides an effective solution for producing components made of difficult-to-machine materials like titanium, zirconium, etc., and intricate shapes, which are not possible by conventional machining methods. Due to large number of process parameters and responses lots of researchers have attempted to model this process. This paper reviews the research trends in WEDM on relation between different process parameters , include pulse on time, pulse off time, servo voltage, peak current, dielectric flow rate, wire speed, wire tension on different process responses include material removal rate (MRR), surface roughness (Ra), sparking gap (Kerf width), wire lag (LAG) and wire wear ration (WWR) and surface integrity factors. Furthermore, different types of WEDM methods introduced and discussed. In addition the paper highlights different modelling and optimization methods and discussed their advantage and disadvantage. The final part of the paper includes some recommendations about the trends for future WEDM researches.

In the present paper some experimental analyses of Dacron © 360 woven with and without surface treatment are presented to evaluate the effect of this treatment on the constitutive behaviour. This woven, widely adopted in sail manufacturing, is obtained by weaving polyethylene terephthalate (PET) yarn and it shows some peculiar features due to the manufacturing process. The experimental tensile tests, clearly show the orthotropy behaviour of the material. The effect of the treatment results in a stiffer behaviour especially along the warp and bias direction and in an increment of ultimate strength in all directions.

A safe and healthy workplace is important for sustainable manufacturing. Green machining is a metal cutting process that does not use a cutting fluid and, because it is less detrimental to the environment, it is fast being adopted by metal cutting industries. In conventional machining, Metal Working Fluids (MWFs) are widely used to obtain a smoother machining process, a longer tool life, and a better surface finish. Unfortunately, metalworking fluids also have several negative health, production cost, and environmental impacts. This paper focuses on an experimental investigation into the role of green or dry machining on tool life and surface finish, in the machining of ductile cast iron FCD700. A comparative study of turning experiments, under dry and wet cutting conditions, using commercial oil and palm oilbased MWFs, was conducted using the same machining parameter setup. The results show that dry machining performance is comparable to that of wet machining. It was found that the performance of wet machining, in terms of tool life, was better than dry machining; however, the surface quality of dry machining was almost similar to that of wet machining. Furthermore, it was evident that green machining can be conducted at high cutting speeds, low feed rates, and depths of cut, and using suitable coated tools.

As a scalar wave is incident upon a rough surface at grazing angle, the Helmholtz wave equation can be approximated by the parabolic equation. Inverse scattering has been formulated in the form of a pair of coupled integral equations in two unknown functions, i.e., surface current and surface roughness. The aim of this article is to implement this approach for profile reconstruction of complex fractal rough surface. The fractal rough surfaces described by a band-limited Weieztrass-Mandelbrot function are numerically realized using the Monte Carlo method. As the scattering fields along a line parallel to the mean surface are measured or solved with a scalar wave incidence at low grazing angle, the rough surface profile is progressively inverted. Numerical examples show that the reconstructed profile and its parameters such as the fractal dimension, roughness variance, and correlation length are well matched with the simulated surfaces.

From last two decades, plant fiber reinforced polymer/polyester composites have been effectively used in structural and automotive applications. Researchers and manufacturers are looking forward for an effective utilization of these composites. However, despite the outstanding properties in terms of load bearing capacity and environmental sustainability of plant fibers the uptake of these composites are limited due to its poor machinability characteristics. Hence in this paper, Taguchi based fuzzy logic model for the optimization and prediction of process output variable such as surface roughness during Abrasive Water Jet Machining (AWJM) of new class of plant fiber reinforced polyester composites i.e., Discontinuously Reinforced Caryota Urens Fiber Polyester (DRCUFP) composites has been explored. Initially machining experiments has been carried out using L27 orthogonal array obtained from Taguchi Design of Experiments (TDOE). Finally, Taguchi based fuzzy logic model has been develo...

In this study, the effect of roughness of particles on flotation efficiency along with surface forces among interacting particles was investigated. Glass beads representing smooth spherical particles with a size fraction of -150+90 μm were used. The etching technique was used to produce roughness of different degrees. Microflotation of round+smooth, and its corresponding etched samples were used to evaluate the efficiency of flotation in the case of smooth and rough systems. Atomic Force Microscope (AFM) was used to reveal the interaction forces between the smooth and rough surfaces. According to the results, roughness of particles increased the flotation efficiency. Although the roughness of particles increased with the etching, excess etching time caused a decrease on the roughness and in turn in the flotation recoveries. The interaction forces between the glass beads changed from repulsion to attraction with the increasing hexadecyltrimethylammonium bromide (HTAB) concentration. ...

Purpose: The purpose of this research paper was to analyze the surface roughness produced by turning process on hard martensitic stainless steel by Cubic Boron Nitride cutting tool. The work piece material was hard AISI 440C martensitic stainless steel. Design/methodology/approach: The experiments were designed using various operating parameters like cutting speed, feed rate and depth of cut. These operating parameters are predominantly used in carrying out the experiments. Findings: Low surface roughness was produced at cutting speed of 225 m/min with feed rate of 0.125 mm/rev and 0.50 mm depth of cut (doc).However, moderate cutting speed of 175 m/min under above feed rate and doc is an ideal operating parameters taking flank wear in to account. Research limitations/implications: While searching for references in turning of martensitic stainless steel, very limited journals are available, but very few literatures are available on turning of AISI 440C hard martensitic stainless steel which was a constraint. Practical implications: The turning of hard martensitic stainless steel brings interesting information on surface roughness, tool wear etc. and further can be extended to turn with different cutting tools. Originality/value: The value of the research work lies in using the results by other researches. The result will upgrade the knowledge about the influence parameters on surface roughness especially on martensitic stainless steel especially on martensitic stainless steels.

The purpose of this study was to evaluate the preimplantation surface finish of the femoral component used in total knee arthroplasty. Nine femoral components from various manufacturers were obtained for analysis. All were fixedbearing, posterior-stabilized implants intended for cemented arthroplasty. Surface characterization involved light profilometry over multiple surface points from the condylar surface, trochlear groove, and the posterior stabilizing cam. Results revealed that the condylar surface roughness was not significantly different when comparing designs with a mean roughness average ranging from 43.6 to 116 nm. The trochlear surface was generally similar to that of the condyles in most implants, although significant differences were seen in 2 implants (P Ͻ .05). Of note, the articular surface of the stabilizing cam was uniformly rougher than the condylar surface in all implants and significantly rougher (P Ͻ .

The surface finish was extensively studied in usual machining processes (turning, milling, and drilling). For these processes, the surface finish is strongly influenced by the cutting feed and the tool nose radius. However, a basic understanding of tool/surface finish interaction and residual stress generation has been lacking. This paper aims to investigate the surface finish and residual stresses under the orthogonal cutting since it can provide this information by avoiding the effect of the tool nose radius. The orthogonal machining of AA7075-T651 alloy through a series of cutting experiments was performed under dry conditions. Surface finish was studied using height and amplitude distribution roughness parameters. SEM and EDS were used to analyze surface damage and built-up edge (BUE) formation. An analysis of the surface topography showed that the surface roughness was sensitive to changes in cutting parameters. It was found that the formation of BUE and the interaction between the tool edge and the iron-rich intermetallic particles play a determinant role in controlling the surface finish during dry orthogonal machining of the AA7075-T651 alloy. Hoop stress was predominantly compressive on the surface and tended to be tensile with increased cutting speed. The reverse occurred for the surface axial stress. The smaller the cutting feed, the greater is the effect of cutting speed on both axial and hoop stresses. By controlling the cutting speed and feed, it is possible to generate a benchmark residual stress state and good surface finish using dry machining.

ABSTRACT Circular vibration milling (CVM) is achieved by vibrating a milling cutter about the machine tool spindle axis in a circular path, in addition to its rotary motion. CVM has been proven capable of producing better surface finishes on difficult to cut materials. However, the CVM process is far slower than conventional milling process. In circular vibration planing (CVP) process, the cutting tool is clamped without rotation and fed at a speed comparable to the feed speed of conventional milling. By superimposing circular vibration motion, necessary cutting speed could be achieved keeping the feed speed at realistic values. Inconel 718 was machined by CVP and conventional milling at a similar feed rate. It was observed that CVP could reduce tool wear and hence produce better surface finishes than conventional milling. A geometric simulation showed a major difference between uncut chip shapes of the two processes. The difference of uncut chip shapes suggests that in CVP process, less rubbing occurs between tool flank face and work before the tool penetrates in to the work to form a chip. The reduced rubbing of the flank face is proposed as the reson for reduced tool wear in CVP when compared with conventional milling.

Hard turning has gained substantial response in metal machining since it has substituted the cycle of traditional process i.e. turning, heat treatment and finish grinding associated with hard parts. This current research goals at evolving an electrorheological fluid damper for reducing vibrations of tools and endorsing improved machining results during hard turning. The ER fluid performs like a spring having nonlinear vibration features tackled by configuration of ER fluid, the electric parameters of electric field and the shape of plunger. Turning investigations are conducted to attain a set of electrical compositional and shape constraints which will reduce tool vibrations and endorse improved cutting performance throughout turning of steel EN24 of 49 HRC with minimum fluid application. It is perceived that utilization of ER fluid damper decreases tool vibrations and increases turning performance efficiently. If this awareness gets commercialize it will beneficial for machining industries.

Several methods have been developed for the computerized generation of space-filling curves, but these curves have never been used for NC tool-path generation. The paper discusses the application of space-filling curves as tool paths for sculptured-surface machining. Tool paths that are space-filling curves, single-direction conventional paths, and 2-direction conventional paths are compared. The efficiency ratings of the paths require further testing, but the preliminary conclusions are favourable for space-filling curves.

Effects of different insert nose radius, cutting speeds and feed rates on the surface roughness of the AISI 306 stainless steel (SS316L), which are used in medical surgery tools. SS316L had been machined with cutting tool at 0.4 mm 0.8 mm, and 1.2 mm of nose radius, at 100, 130, 170 m/min of cutting speeds and at 0.1, 0.125, 0.16 mm/rev of feed rates. Depth of cut was kept constant at 0.4 mm. It is seen that the insert nose radius, feed rates, and cutting speed have different effects on the surface roughness of SS316L. The lowest surface roughness was 0.225 µm in average, has been obtained when using insert with 1.2 mm of nose radius at the lowest feed rate (0.1 mm/rev). The highest surface roughness was 1.838 µm has been measured when using insert with 0.4 mm of nose radius at the highest feed rate (0.16 mm/rev). Results from analysis of variance (ANOVA) shown that the cutting speed was not contribute significantly effect on the surface roughness, compared to feed rate and insert nose radius. Surface roughness was decreased with decreasing of the feed rate. Machining with bigger insert nose radius has capability to obtain lower surface roughness than smaller insert nose radius. This phenomenon cause by maximizing uncut chip thickness which decreased with increasing of insert nose radius.

Chemical mechanical planarization (CMP) process has been widely used in the semiconductor manufacturing industry for realizing highly finished (Ra 1 nm) and planar surfaces (WIWNU 1%, thickness standard deviation (SD) 3 nm) of in-process wafer polishing. The CMP process is rather complex with nonlinear and non-Gaussian process dynamics, which brings significant challenges for process monitoring and control. As an attempt to address this issue, a method is presented in this paper that integrates nonlinear Bayesian analysis and statistical modeling to estimate and predict process state variables, and therewith to predict the performance measures, such as material removal rate (MRR), surface finish, surface defects, etc. As an example of performance measure, MRR is chosen to demonstrate the performance prediction. A sequential Monte Carlo (SMC) method, namely, particle filtering (PF) method is utilized for nonlinear Bayesian analysis to predict the CMP process-state and for tackling the process nonlinearity. Vibration signals from both wired and wireless vibration sensors are adopted in the experimental study conducted using the CMP apparatus. The process states captured by the sensor signals are related to MRR using design of experiments and statistical regression analysis. A case study was conducted using actual CMP processing data by comparing the PF method with other widely used prediction approaches. This comparison demonstrates the effectiveness of the proposed approach, especially for nonlinear dynamic processes.

Free-form surfaces are being used in a growing number of engineering applications, especially in injection molding of consumer products. Decreasing the manufacturing cost and time of these molds will improve the efficiency of manufacturing injection molded consumer products. This paper is motivated by the need for simple strategies to improve the quality of and decrease the time required to machine free-form surfaces. We present two methods to improve the surface finish of parts finished with ball-nose endmilling. In the first method the surface finish is improved by finding an optimal orientation angle for the workpiece relative to the machining axis. In the second method finish is improved by adaptively varying the step-size when using raster toolpaths. The adaptive variation is controlled by a user-defined finish improvement factor, where the spacing density is increased only if the improvement in surface finish is greater than the finish improvement factor. These methods are implemented using an analytical model of the workpiece surface finish based on the mean scallop height of the machined surface. Results from the analytical model are verified with machining experiments, and we show that the adaptive spacing strategy can improve the surface quality by more than 50% with a small increase in the toolpath length. To achieve a similar improvement in surface quality by uniformly decreasing the path spacing results in a much larger increase in the toolpath length. The strategies discussed in this paper allow process planners intuitive control over the toolpath layout and spacing and improve the efficiency of machining high quality parts.

The final machining (or finishing) of precision parts with high level of surface finish and close tolerance is making the application of magnetic abrasive finishing technology increasingly important. Magnetic abrasive flow finishing (MAFF) is a new abrasive finishing process combining the features of abrasive flow finishing (AFF) and magnetic abrasive finishing (MAF). MAFF provides a high level of surface finish and close tolerances for wide range of industrial application. This paper focuses on the modeling and simulation for the prediction of surface roughness on the workpiece surface finished by MAFF process. A finite element model is developed to find the magnetic potential distribution in the magnetic abrasive brush formed during finishing action and then it is used to evaluate machining pressure, surface finish and material removal. The simulation results are compared with the experimental results available in the literature. The simulated workpiece surface roughness shows features similar in nature to the experimental results.