Surface Finish

The snow surface is very dynamic, and the roughness of the snowpack surface varies spatially and temporally. The snow surface roughness influences the movement of air across the snow surface as well as the resulting transfers of energy, and is used to estimate the sensible and latent heat fluxes to and/or from the snow surface to the atmosphere. In the present work we used different metrics, including the random roughness, autocorrelation, and fractal dimension, geometric roughness length, curvature, and power spectrum density to characterize the roughness of a typical snow surface. The data for the surface come from airborne LIDAR measurements taken during from the NASA Cold Land Process Experiment in late March 2003 at the Fraser Alpine intensive study area. The surface elevation data were rotated to be parallel to the dominant wind direction and were interpolated to a 1-m resolution. We provide a comparison of methods and present their possible applicability for other datasets.

An understanding of wetting is important for many applications, including superhydrophobic self-cleaning and low-drag surfaces. Many natural examples of such surfaces exist, including insect legs, bird feathers, and plant leaves. The mechanism of superhydrophobicity on these surfaces is known to be related to their hierarchical roughness (i.e., roughness on micro and nano length scales), though the precise role of hierarchical roughness is not yet well understood. We present a two-dimensional thermodynamic model of the wetting of a hierarchically-grooved surface for droplets with variable Bond number. By investigating wetting phase diagrams over the microscale parameter space, we find that for negligible Bond number, surfaces with single-scale roughness are superhydrophobic only in small regions of the phase space-most notably in regions where the droplet is much larger than the size of the surface features-while the addition of nanoscale roughness greatly extends the range of drop sizes for which high contact angles are attained. We also investigate the case of non-negligible Bond number, for which we observe significant changes in the wetting phase diagram arising from gravity-induced interface deformations.

Theory and Simulation of Droplet Wetting on Patterned Surfaces 1 AZAR SHAHRAZ, ALI BORHAN, KRISTEN FICHTHORN, Penn State University -Liquid droplets can have multiple wetting modes on physically patterned surfaces, each corresponding to a (meta)stable state. For example, in the Cassie mode, the droplet resides on top of the pattern, while in the Wenzel mode, the droplet penetrates into the pattern. In this work, we study the wetting of patterned surfaces on two different length scales: on the nano-scale using molecular dynamics (MD) and on the macro-scale by minimizing free-energy expressions for various droplet wetting modes. We find that surface topography, size, and initial position of the droplet strongly affect the wetting states and contact angles. In the small Bond-number (small droplet) regime, the surface topography can be scaled by the droplet size, such that the preferred wetting modes and contact angles become independent of droplet size for surfaces with the same scaled topography. MD simulations and theory are in good agreement for small Bond numbers. For moderate to large Bond numbers, gravity plays an important role and MD simulations cannot accurately describe wetting. We create wetting phase diagrams and find that our predictions are in good agreement with experiment. The resulting wetting phase diagrams may serve as a guideline in creating surfaces with desired wettability.

The American Physical Society Kinetics of droplet wetting-mode transitions on grooved surfaces: Forward flux sampling AZAR SHAHRAZ, ALI BORHAN, KRISTEN FICHTHORN, Pennsylvania State University -Liquid droplets on rough surfaces typically exhibit either the Cassie wetting mode, in which the droplet resides on top of the roughness, or the Wenzel mode, in which the droplet penetrates into the roughness. For a fixed surface topology and droplet size, one of these modes is the global free-energy minimum. However, the other state is often metastable and longlived due a free-energy barrier that hinders the transition between the two wetting states. Metastable wetting states have been observed experimentally and we also observe them in molecular dynamics (MD) simulations of a droplet on a grooved surface. Using forward flux sampling, we study the kinetics of the Cassie-Wenzel transition. The global-minimum wetting states that emerge from our nanoscale MD approach are consistent with those predicted by a macroscopic model for the free energy. We find that the free-energy barrier for this transition depends on the droplet size and surface topology. A committor analysis indicates that the transition-state ensemble consists of droplets that are on the verge of initiating/breaking contact with the substrate below the grooves.

The paper presents certain problems related to the lubrication of textured surfaces. It was noted that for a specific load, the lubrication effectiveness will depend on the shape, size and mutual distribution of the texture’s elements. Proposals for determining the lubrication irregularity parameters were presented for textures with a rectangular mesh and round recesses. The experimental part presents the laser texturing methodology, tribological testing methodology and preliminary test results where the significant role of the relationship between the trajectory of motion and the texture mesh was demonstrated.

An off-line image analysis algorithm and software is developed for the calculation of line-edge roughness (LER) of resist lines, and is successfully compared with the on-line LER measurements. The effect of several image-processing parameters affecting the fidelity of the off-line LER measurement is examined. The parameters studied include the scanning electron microscopy magnification, the image pixel size dimension, the Gaussian noise-smoothing filter parameters, and the line-edge determination algorithm. The issues of adequate statistics and appropriate sampling frequency are also investigated. The advantages of off-line LER quantification and recommendations for the on-line measurement are discussed. Having introduced a robust algorithm for edge-detection in Paper I, Paper II [V. Constantoudis et al., J. Vac. Sci. Technol. B 21, 1019 (2003)] of this series introduces the appropriate parameters to fully quantify LER.

The problem of surface and line-edge roughness characterization and prediction is discussed. Different roughness parameters, such as the root mean square deviation ͑rms or ͒, the fractal dimension, and the Fourier spectrum, are presented and compared. These roughness parameters for three negative tone resists ͑wet and plasma developed͒ are analyzed versus exposure dose, photoacid generator concentration, and plasma development conditions. Finally, a molecular type simulator is used to predict the experimental roughness behavior.

Silicon-containing, plasma-developed resists are characterised by surface (SR) and line-edge roughness (LER) measurements as functions of the exposure dose and plasma development conditions. Specifically, bilayer siloxane-based resists of different molecular weight distributions, and single-layer silylated chemically amplified resists are evaluated with measurements of SR and LER, while the results are compared with those of solution-developed chemically amplified resists. We show that plasma-developed systems can have low LER provided the resist material, the resist chemistry, and the processing conditions are chosen appropriately.

The requirements of welded components are rising continuously through increasing demands in engineering. But in engineering not only the quality of welds is important also an economic and timesaving production is crucial. Especially in welding of large cross sections economization potential is existing and significant. Beside the welding technique itself the joint preparation is a major part of work. Electron beam welding has some major advantages in this area. Due the high energy density a very short welding time as well as a small heat affected zone can be achieved. Furthermore the joint preparation can be held simple. Nevertheless, a careful machining and cleaning of the joint surfaces is recommended in literature. In addition to geometric tolerances a specific surface roughness should be kept. These statements are quite general and unspecific. In this contribution a systematic investigation on the influence of joint preparation on the joint properties is presented. By performing several welding experiments with different surface roughness this study provides empirical conclusions. Beside the microscopic investigation of different cross sections and mechanical tests of the welded samples also the process stability during welding was reviewed.

Державний університет «Житомирська політехніка» Шляхи удосконалення процесу обробки плоских поверхонь деталей фрезеруванням На основі аналізу зростаючих вимог до якості обробки деталей, підвищення надійності їх функціонування розглянуто питання щодо збільшення рівня продуктивності обробки плоских поверхонь деталей за рахунок використання торцевих фрез, оснащених надтвердими матеріалами. Встановлено напрями удосконалення процесу обробки плоских поверхонь шляхом використання нових комбінованих схем обробки поверхонь та удосконалення геометрії різальних частин фрез. Встановлено перспективні напрями створення нових конструкцій торцевих фрез із використанням складних формоутворюючих рухів. Визначено переваги кінематичного перетворення колової траєкторії формоутворюючих рухів різальних та деформуючих елементів, що дає можливість забезпечення рівномірної шорсткості по ширині обробленої поверхні. Запропоновано раціональні режими обробки плоских поверхонь деталей удосконаленими комбінованими методами. Ключові слова: торцеве фрезерування; торцева фреза; косокутне різання; ступінчасті фрези; різальні елементи. Постановка проблеми. Станини верстатів та інших машин з плоскими протяжними поверхнями, якими переміщуються рухомі вузли (супорти, каретки, шпиндельні бабки, задні центри, допоміжні пристрої тощо), напрямні планки, стійки вантажопідіймачів, базові деталі вимірювальних машин, накладні напрямні ковзання становлять більше 15 % об'єму продукції машинобудування і металообробки. Матеріалами для виготовлення таких деталей є чавуни, конструкційні й леговані сталі. У технологічних процесах виготовлення деталей від 10 до 50 % повинні мати шорсткість оброблених поверхонь не більше 1,6 мкм. Останнім часом чистова обробка плоских поверхонь все частіше виконується торцевим фрезеруванням, як правило, стандартними торцевими фрезами, які мають низку недоліків. Їх усунення є важливим завданням, що може вирішуватися у кількох напрямах. Одним з них є проєктування більш досконалих конструкцій фрез із комбінованими схемами різання з використанням, у тому числі, комбінування методів різання і поверхневого пластичного деформування (ППД). Під час розробки спеціальних торцевих фрез з комбінованими схемами різання основною метою є встановлення раціональних конструктивних параметрів фрез та режимів експлуатації. Крім цього, застосування чистових торцевих фрез із комбінованими схемами різання зумовлює необхідність вивчення особливостей кінематики обробки. Дослідження та вирішення питань, спрямованих на підвищення якості обробки плоских поверхонь деталей, є актуальним задачею і має велике значення на сучасному етапі розвитку інструментального виробництва та машинобудування в цілому. Аналіз останніх досліджень та публікацій. У низці досліджень [4-9] було розглянуто питання розробки нових способів обробки і проєктування більш досконалих конструкцій фрез із комбінованими схемами різання, а також з комбінованими схемами обробки (фрезерування-вигладжування тощо). Забезпечення якісної обробки плоских поверхонь деталей під час нестаціонарної обробки реалізується за рахунок використання нових методів обробки і конструкцій різальних інструментів, раціональних режимів різання. Для забезпечення стійкості торцевих фрез застосовуються ступінчасті схеми різання та безвершинна геометрія різальних ножів, оснащених надтвердими матеріалами (НТМ). Питанням забезпечення якісної і продуктивної обробки плоских поверхонь деталей машин торцевим фрезеруванням присвячено велику кількість робіт вітчизняних і закордонних вчених. Однак існуючі рішення в цьому напрямі мають частковий характер, у них відсутні основи створення ефективного інструменту для фрезерних верстатів, невирішені проблеми його працездатності, надійності, особливостей конструктивних елементів. Суттєвим резервом підвищення продуктивності обробки є можливість створення нових конструкцій торцевих фрез, які б дозволили поєднати декілька операцій обробки (чорнову, напівчистову і чистову) за один прохід. В умовах високої вартості верстато-годин на сучасних верстатах це має велике значення на сьогоднішньому етапі розвитку інструментального виробництва та машинобудування.

Spin hall effect (SHE) in thin films is inherited by surface roughness. Although roughness effect on SHE has been studied in thin films, but roughness is not only parameter in rough surfaces. Our results show that how other statistical parameters of rough surface play important role in SHE. In this paper we investigate theoretically the effects of correlated surface roughness in the SHE with self affine fractal surface in non-heavy metallic thin films in the frame work of the Born approximation. The surface roughness is described by the k-correlation model and is characterized by the roughness exponent H (0 ≤ H ≤ 1), the in plane correlation length ξ and the rms roughness amplitude δ. We show that the spin Hall angle can increase by one order of magnitude when H decreasing from H = 1 to H = 0. We also demonstrate the SHE for surface roughness with distribution function of the Gaussian profile is mainly contributed by the side jump scattering while for that with a non-Gaussian profile, both side jump and skew scattering are present. our achievements demonstrate the important role of roughness texture profile for SHE in non-heavy metals.

This article presents the results of pilot studies on the lubrication of the blankholder zone in sheet metal forming using a pressurised lubricant. The authors invented a method and built a special tribometer for pressure-assisted lubrication. This approach reduces friction in sheet metal forming processes compared to conventional lubrication. Moreover, the artificial neural network approach combined with a force-directed Fruchterman-Reingold graph algorithm and Spearman's correlation was used for the first time to analyse the relationships between the friction process parameters and the output parameters (the coefficient of friction and the resulting surface roughness of the sheet metal). The experimental tests were conducted utilising strip drawing on four grades of steel sheets known to be outstanding for deep-drawing quality. Different oils, oil pressures and contact pressures were used. Artificial neural network models were used for the first time to determine these relationships in a strip drawing test where every parameter is represented by one node, and all nodes are connected by edges with each other. R Software version 4.2.3 was used to construct the network using the 'qgraph' and 'networktools' packages. It was found that friction conditions had a highly significant negative correlation with coefficient of friction (COF) and a moderately significant negative correlation with the final surface roughness. However, the initial surface roughness of the as-received sheets had a negative correlation with the COF and a positive one with the resulting surface roughness of the sheet metal. The parameters most related to the COF are the strength coefficient, the ultimate tensile strength and the friction conditions (dry friction or pressurised lubrication). Spearman's correlation coefficients showed a strong correlation between the kinematic viscosity and the friction conditions.

Drawbeads are used when forming drawpieces with complex shapes to equalise the flow resistance of a material around the perimeter of the drawpiece or to change the state of stress in certain regions of the drawpiece. This article presents a special drawbead simulator for determining the value of the coefficient of friction on the drawbead. The aim of this paper is the application of artificial neural networks (ANNs) to understand the effect of the most important parameters of the friction process (sample orientation in relation to the rolling direction of the steel sheets, surface roughness of the counter-samples and lubrication conditions) on the coefficient of friction. The intention was to build a database for training ANNs. The friction coefficient was determined for low-carbon steel sheets with various drawability indices: drawing quality DQ, deep-drawing quality DDQ and extra deep-drawing quality EDDQ. Equivalents of the sheets tested in EN standards are DC01 (DQ), DC03 (DDQ) and DC04 (EDDQ). The tests were carried out under the conditions of dry friction and the sheet surface was lubricated with machine oil LAN46 and hydraulic oil LHL32, commonly used in sheet metal forming. Moreover, various specimen orientations (0 • and 90 • ) in relation to the rolling direction of the steel sheets were investigated. Moreover, a wide range of surface roughness values of the counter-samples (Ra = 0.32 µm, 0.63 µm, 1.25 µm and 2.5 µm) were also considered. In general, the value of the coefficient of friction increased with increasing surface roughness of the counter-samples. In the case of LAN46 machine oil, the effectiveness of lubrication decreased with increasing mean roughness of the counter-samples Ra = 0.32-1.25 µm. With increasing drawing quality of the sheet metal, the effectiveness of lubrication increased, but only in the range of surface roughness of the counter-samples in which Ra = 0.32-1.25 µm. This study investigated different transfer functions and training algorithms to develop the best artificial neural network structure. Backpropagation in an MLP structure was used to build the structure. In addition, the COF was calculated using a parameter-based analytical equation. Garson partitioning weight was used to calculate the relative importance (RI) effect on coefficient of friction. The Bayesian regularization backpropagation (BRB)-Trainbr training algorithm, together with the radial basis normalized-Radbasn transfer function, scored best in predicting the coefficient of friction with R 2 values between 0.9318 and 0.9180 for the training and testing datasets, respectively.

The main aim of this study was to perform a scoping review on the effects of the grit-blasting on titanium base surfaces concerning the bonding of resin-matrix luting materials and prosthetic structures. Methods: The search was conducted in PubMed (via the National Library of Medicine) and Scopus for articles published from January 2010 until July 2025 using the following combinations of search terms: "surface" AND "abutment" AND "titanium" AND "sand blasting" OR "grit blasting" AND "retention" OR "adhesion" OR "resin cement". Results: The search identified 36 studies, of which 19 were considered relevant for this study. Results showed higher roughness values (0.6-2.3 μm) of the titanium base surfaces after grit-blasting when compared to surfaces free of modification (0.04 μm). Also, macro-and micro-scale retentive areas were performed using alternative methods such as laser texturing approaches. Surfaces modified by grit-blasting showed higher shear bond strength to resin-matrix cements at around 33 and 36 N/mm 2 when compared to untreated surfaces (11-18 N/ mm 2 ). Grit-blasted surfaces showed higher mean values of tensile bond forces to resin-matrix cements ranging from 305 up to 853 N when compared to untreated surfaces (160-250 N). Conclusions: Machined titanium base free of surface modification revealed low roughness and non-retentive regions for resin-matrix luting materials. After grit-blasting, roughness increased, and the morphological aspects of the surfaces established a mechanical interlocking of the resin-matrix luting materials onto the surfaces leading to high bond strength values. The combination of grit-blasting and other physical surface methods can enhance the retention of titanium base to resin-matrix luting agents adhered to prosthetic structures. Clinical significance: Cement-retained implant-supported prostheses depend on the textured titanium surfaces and the type of resin-matrix luting materials. Additionally, the cementation clinical procedure should be associated with the type of resin-matrix luting materials and adhesive systems. Thus, clinicians must be aware on the several parameters to enhance the adhesion of cement-retained prostheses over titanium base for abutments.

In high power RF devices for space, secondary electron emission appears as the main parameter governing the multipactor effect and as well as the e-cloud in large accelerators. Critical experimental activities included development of coatings with low secondary electron emission yield (SEY) for steel (large accelerators) and aluminium (space applications). Coatings with surface roughness of high aspect ratio producing the so-call secondary emission suppression effect appear as the selected strategy. In this work a detailed study of the SEY of these technological coatings and also the experimental deposition methods (PVD and electrochemical) are presented. The coating-design approach selected for new low SEY coatings include rough metals (Ag, Au, Al), rough alloys (NEG), particulated and magnetized surfaces, and also graphene like coatings. It was found that surface roughness also mitigate the SEY deterioration due to aging processes.

The response of the upper ocean to the parameterization of the roughness length z 0 on the air side of the air-sea interface is studied using a one-dimensional mixed-layer model. In particular, it is shown that in the free convection limit when both the wind speed and the friction velocity approach zero, the familiar Charnock formula for the momentum roughness, which relies solely on wind generation, can be modified to account for contributions arising from the thermally generated turbulence. Therefore, a new parameterization is proposed for the momentum roughness length which extends the Charnock formula down to zero friction velocity. The value of a parameter which enters in the new formulation is determined by making use of exsisting free convection surface flux parameterizations. The effect of the new parameterization on the model performance is tested using data from the ocean weathership station Papa (OWS P), and data from the Long-Term Upper-Ocean Study (LOTUS) experiment. Simulations were carried out using a recently developed one-dimensional, second-order, turbulence closure scheme over diurnal as well as seasonal time scales. The findings suggest that the new momentum roughness parameterization improves the overall agreement between the observed and simulated sea-surface temperature (SST).

The paper is devoted to the analysis of the shape of the swash edge line. Formation of the swash boundary is treated as an interfacial phenomenon. The simplest quantitative characteristic of the roughness of interface is its width w, defined as the root-mean-square fluctuation around the average position. For rough interfaces, the scaling with size of the system L is observed in the form w(L) / L f . The concept of scaling supplies a simple framework for classifying interfaces. It is suggested that the fine structure of the swash boundary results from the combined action of the pinning force applied by random defects of the beach and elasticity of distorted swash boundary. The roughness of the swash front was studied at the Mediterranean Sea coast for uprush and backwash flows. Value of exponent f for receding swash front line was 0.64 6 0.02, when in the case of advancing swash the value 0.73 6 0.03 was calculated. The scaling exponent established for the receding phase of the swash is very close to the values of the exponent established for the roughness of the triple line for water droplets deposited on rough surfaces, crack propagation front in Plexiglas, and for the motion of a magnetic domain walls. T he physics of swash, i.e. a layer of water that washes up on the beach after an incoming wave has broken, is complicated and intriguing. It includes perplexing hydrodynamic and sediment transport events 1-4 . The coastal strip is a highly dynamic zone and may include features with the dimensions ranging from microns to kilometers. Beach cusps are often arising in the swash zone presenting obstacles to the propagation of a wave front and promoting its breakdown 1-4 . In our paper, we address the roughness of the moving swash boundary at which a beach, water and air meet. The roughness of the swash edge is characterized by a scaling law that relates the statistical width w of the boundary (i.e. the root-mean-square fluctuation of the edge line around its average position) to its length L via w(L) / L f law 5-10 . We treat the behavior of this boundary as an interfacial phenomenon, without going into details of the formation of edge waves and beach cusps, covered broadly in literature 1-4 . This ''crude'' approach turns out to be productive and reveals the resemblance of the swash line to a broad diversity of effects arising from the random pinning of moving boundaries . Swash consists of two phases: uprush (onshore flow) and backwash (offshore flow). We concentrate mainly on backwash (offshore flow), when water recedes along the beach face. The receding water front is pinned by randomly distributed obstacles, produced by the beach and constituting the roughness of the swash edge line. It is plausible to suggest that the fine structure of the swash edge line results from the combined action of the pinning force applied by defects of the beach and the elasticity of the distorted swash boundary. The problem is common for a number of physical systems comprising interfaces moving in a disordered medium; for example, self-affine crack propagation 5-6 , wet front propagation and movement of interfaces between immiscible liquids in porous media , height distribution of growing surfaces , and growth of magnetic domain walls in disordered media 12 . However, the most investigated situation of interfaces moving over a disordered system of obstacles is the displacement of the triple (three-phase) line at which water, vapor and a rough (or chemically heterogeneous) surface meet . The shape of a triple line disturbed by the presence of random heterogeneities on the solid surface may be derived by a solution of the Laplace equation with the boundary conditions of the Young equation. With some simplifications, this is given by Shanahan 18 and de Gennes 19 . The simplest quantitative characteristic of an interface is its width w, defined as the root-mean-square fluctuation around an average position. For rough interfaces, scaling with size of a system L is observed, which is expressed in the form meaning that the average width w grows as the size L is increased. The concept of scaling introduced in the field of interfaces by Family and Vicsek 20,21 gave a simple framework for classifying interfaces in various processes. Scaling

I would like to thank my committee chair, Dr. Rollin Hotchkiss, for his support, guidance, and teaching throughout the development of this thesis. I would also like to thank committee members Dr. Michael Barber and Dr. Marc Beutel for their valuable comments and review. Dr. David Admiraal at the University of Nebraska-Lincoln gave advice on the development of the construction of the model design and led to the avoidance of headaches during experimental testing. Undergraduate assistants Kayla Culmer and Mike Miraglio provided assistance in the construction and testing of the experimental models. With their help, I was able to complete the research in a timely matter. The support from my peers in Albrook Hyrdaulics Laboratory kept me motivated and in high spirits throughout the whole research process. My family has continued to give me unwavering support and they gave me my basis for the drive and motivation behind this research. I would especially like to thank my wife, Brittany Stuckel-Hill, for her unending love, support, and patience throughout this whole process. If it wasn't for her, I would not be writing this thesis right now.

Burnishing, the plastic deformation of the workpiece surface due to sliding contact with a tool called burnisher, is a finishing operation widely used in various industries. In this work, impacts of the initial surface roughness Ra of the workpiece being burnished, the nature of friction in the contact zone, and the clamping force on the stability and energy efficiency of burnishing have been investigated. Experiments have been conducted with and without lubricant, represented by low-viscosity deep-hydrogenated fraction of sour oils, at initial surface roughness Ra of 0.8 and 1.25 μm and variable (100–200 N) clamping force. A key process indicator, which largely controls mechanics of burnishing, the temperature in the tool-workpiece contact zone has been measured using natural thermocouple method. Microhardness of the workpiece surface after burnishing has also been measured. It has been shown that changes in the temperature of the tool-workpiece contact zone are proportional to the...

The ball burnishing process is done to improve the surface finish of workpieces that have been previously machined. In this article we present the results of tests performed with this process that was applied to workpieces with a convex or concave surface of two different materials: aluminum A92017 and steel G10380. An experiment to do the tests was designed. The results of measurements of surface roughness are presented in this paper as well. These results are compared to those measured in the workpieces before being burnished. After that conclusions are drawn about the improvement of surface roughness applied to the workpieces through the ball burnishing process. The main innovation of this paper is that we work with concave and convex geometries. We also obtain a table of recomended parameter values for the process.

In this study, we analyzed the effects of vibration assistance, combined with a ball burnishing process, in terms of topology, residual stresses, and tribological properties on 316L shafts. The burnishing variables consisted of the variation of the input force, the number of passes, and the activation of the vibration assistance, which is based on a 40 kHz frequency and 8 μm of vibration amplitude, derived in a screening design of three factors. The results show that the medium–high level of burnishing force, high level of the number of passes, and the activation of the vibration assistance are the best options in order to improve the average roughness, the microstructure, the increase in the compressive residual stresses, and the wear enhancement, besides all variables being significant in the p-value analysis through ANOVA. Statistically, the vibration-assisted ball burnishing improved the average roughness by 2.9%, enlarged the von Mises stress on the surface by 11.5% and enhance...

This study refers to the study of the ball-burnishing process assisted by vibration. This study begins by considering that this vibration helps to make the development of this finishing process easier because it helps to deform the workpiece material more easily. Because a similar tool is not available in the market, a tool that can perform the study needed to be designed, characterised and manufactured to conduct the study by considering the critical components that are involved in the design and the physical model that characterises the operation. For these criteria, the tool operation is also characterised by evaluating the surface roughness that remains after the process occurs. Workpieces of aluminium and steel were used for the experimental validation. These results were compared to those obtained using the same tool without vibration. The roughness results obtained using the ball-burnishing vibration-assisted process improve compared to those obtained using the process withou...

Nanostructured plasmonic metamaterials, including optical nanoantenna arrays, are important for advanced optical sensing and imaging applications including surface-enhanced fluorescence, chemiluminescence, and Raman scattering. Although designs typically use ideally smooth geometries, realistic nanoantennas have nonzero roughness, which typically results in a modified enhancement factor that should be involved in their design. Herein we aim to treat roughness by introducing a realistic roughened geometry into the finite element (FE) model. Even if the roughness does not result in significant loss, it does result in a spectral shift and inhomogeneous broadening of the resonance, which could be critical when fitting the FE simulations of plasmonic nanoantennas to experiments. Moreover, the proposed approach could be applied to any model, whether mechanical, acoustic, electromagnetic, thermal, etc, in order to simulate a given roughness-generated physical phenomenon.

special attention should be given to the pressure sensing diaphragms for the measurements of friction factor in micro-tubes. In their research, they focused on how the micro-tube diameters influenced the transition region. This study complements their study. Using their suggested diaphragm selection method, micro-tubes with diameters around 1000ȝm and five different surface roughness values ranging from 0 to 4.3ȝm were used to study the friction factor characteristics across the laminar, transition and turbulent regions (800<Re<7000). Moreover, the influence of surface roughness on the start and end of the transition region was observed. It was concluded that a narrower transition region can be seen with an increase in the surface roughness.

According to the recent literature survey, it was concluded that the friction factor in mini-and micro-tubes could be predicted accurately by using macro-scale theory. However, certain issues should be further investigated. They are: (a) the effect of inner surface roughness and (b) the effect of mini-and micro-tube diameters on the start and end of the transition region. Moreover, only a few studies investigated the effect of heating on friction factor in mini-and micro-tubes, especially, in the transition region. Therefore, an experimental setup was built in this study to measure the pressure drop for the horizontal mini-and micro-tubes under the isothermal and uniform wall heat flux boundary conditions. Distilled water was used as the test fluid. Seven stainless steel minitubes (2000µm to 508µm in inner diameters) with various surface roughness values (1.94µm to 5.30µm) were used as the test section. The experimental results clearly showed the effect of heating and roughness on friction factors in the laminar, transition, and turbulent regions. For the friction factors under isothermal condition, the mini-tubes had a narrower transition range due to the roughness when compared to the macro-tubes. For the friction factor under heating condition, the laminar data and the start of transition were different from the isothermal case. Under heating condition, the narrower transition range due to the roughness was also observed in the mini-tubes. However, the effect of heating was not seen on the end of transition and in the turbulent region.

Conventionally the selection of parameters depends intensely on the operator-s experience or conservative technological data provided by the EDM equipment manufacturers that assign inconsistent machining performance. The parameter settings given by the manufacturers are only relevant with common steel grades. A single parameter change influences the process in a complex way. Hence, the present research proposes artificial neural network (ANN) models for the prediction of surface roughness on first commenced Ti-15-3 alloy in electrical discharge machining (EDM) process. The proposed models use peak current, pulse on time, pulse off time and servo voltage as input parameters. Multilayer perceptron (MLP) with three hidden layer feedforward networks are applied. An assessment is carried out with the models of distinct hidden layer. Training of the models is performed with data from an extensive series of experiments utilizing copper electrode as positive polarity. The predictions based ...

This paper develops a single order mathematical model for correlating the various electrical discharge machining (EDM) parameters and performance characteristics utilizing relevant experimental data as obtained through experimentation. Besides the effect of the peak ampere, pulse on time and pulse off time on surface roughness has been investigated. Experiments have been conducted on titanium alloy Ti-6Al-4V with copper electrode retaining negative polarity as per Design of experiments (DOE). Response surface methodology (RSM) techniques are utilized to develop the mathematical model as well as to optimize the EDM parameters. Analysis of Variance (ANOVA) has been performed for the validity test of fit and adequacy of the proposed models. It can be seen that increasing pulse on time causes the fine surface until a certain value and afterward deteriorates in the surface finish. The excellent surface finish is investigated in this study in the case of the pulse on time below 80 µs. This result guides to pick the required process outputs and economic industrial machining conditions optimizing the input factors.

This paper explores the develop optimized model to investigate the effects of peak current, pulse on time and pulse off time in electric discharge machining (EDM) performance on titanium alloy utilizing copper tungsten as electrode and positive polarity of the electrode. The experiments are carried out on Ti6Al4V. Experiments were conducted by varying the peak current, pulse on time and pulse off time and the corresponding values of surface roughness (SR) were measured. A mathematical model for correlating influences of these variables and surface finish of the workpiece is developed in this paper. Design of experiments (DOE) method and response surface methodology (RSM) techniques are implemented. The validity test of the fit and adequacy of the proposed models has been carried out through analysis of variance (ANOVA). The obtained results evidence that as the surface roughness increases with peak current and pulse on time increases. The effect of pulse off time on surface roughness changes with peak ampere. The excellent surface finish is investigated in this study at short pulse on time. The optimum machining conditions in favor of surface roughness are estimated and verified with proposed optimized results. It is observed that the developed model is within the limits of the agreeable error when experimental. This result leads to desirable surface roughness and economical industrial machining by optimizing the input parameters.

Manufacturing process is significantly altered by tool wear and this factor creates intricate issues that form a hindrance in attaining manufacturing automation. The other vital parameters determining the tool life are the dimensional accuracy and surface roughness of the workparts. In this research work, an attempt is being made to conduct machining studies on martensitic stainless steel AISI410 to analyze the effect of crater wear and surface roughness in TiN coated WC tool. The crater wear and surface roughness values are initially recorded. The recorded data are used as input in the ANOVA plinth and subsequently used for developing mathematical tool wear models using multiple regression analysis (MRA). The results from ANOVA reveal that the cutting speed influences the surface roughness more significantly than feed rate and depth of cut. Further, it is emphasized that, the crater wear is affected more by feed rate as compared to the cutting speed. Consequently, the metallographic studies using scanning electron microscope (SEM) are conducted based on which the effects of crater wear on the TiN coated WC cutting tool are plotted and analyzed.

Human-machine haptic interaction is typically detected by variations in friction, roughness, hardness, and temperature, which combines to create sensation of surface texture change. Most of the current technologies work to simulate changes in tactile perception (via electrostatic, lateral force fields, vibration motors, etc.) without creating actual topographical transformations. This makes it challenging to provide localized feedback. Here, a new concept for on-demand surface texture augmentation that is capable of physically forming local topographic features in any predesigned pattern is demonstrated. The transparent, flexible, integrable device comprises of a hybrid electrode system with conductive hydrogel, silver nanowires, and conductive polymers with acrylic elastomer as the dielectric layer. Desired surface textures can be controlled by a predesigned pattern of electrodes, which operates as independent or interconnected actuators. Surface features with up to a height of 0.1...

The scaling behavior of cyclical surface growth (e.g. deposition/desorption), with the number of cycles n, is investigated. The roughness of surfaces grown by two linear primary processes follows a scaling behavior with asymptotic exponents inherited from the dominant process while the effective amplitudes are determined by both. Relevant non-linear effects in the primary processes may remain so or be rendered irrelevant. Numerical simulations for several pairs of generic primary processes confirm these conclusions. Experimental results for the surface roughness during cyclical electrodeposition/dissolution of silver show a power-law dependence on n, consistent with the scaling description.

The regression analysis process is used to study and predicate the surface response by using the design of experiment (DOE) as well as roughness calculation through developing a mathematical model. In this study; response surface methodology and the particular solution technique are used. Design of experiment used a series of the structured statistical analytic approach to investigate the relationship between some parameters and their responses. Surface roughness is one of the important parameters which play an important role. Also, its found that the cutting speed can result in small effects on surface roughness. This work is focusing on all considerations to make interaction between the parameters (position of influence) because laser power directly depends on cutting speed with high gas pressure and vice versa to obtain a less surface roughness. Data analysis showed that the lower value for roughness was (0.68) µm and the high roughness was (8.56) µm.  The model values for consid...

detect the vibration, thus different detected values are obtained. The results are compared to the IRI observation. ML method gives better result compared to RMS. This study finds little relationship between IRI and acceleration data from vibration collected from smartphones.

Experimental results on mechanical efficiency and durability of spur gears are presented. Reducing the power losses and increasing the reliability of gears are fundamnetal aspects of the design of transmissions. In order to analyze the tribological performance of innovative coatings and laser texturing, three different types of spur gears were tested: standard carburized gears, WC/C-coated carburized gears, and carburized gears with laser texture pattern. Tests have been carried out through a power recirculating test rig equipped with a single-stage transmission; power losses were evaluated by analyzing the torque-meters signals; several pictures of the teeth were taken at scheduled times to monitor the wear progression. In conclusion, results are presented and discussed.

The effect of processing parameters on the surface roughness parameter Rz (mean peak-to-valley height) in CNC machining of Anatolian chestnut (Castenia sativa Mill.) wood species used in the woodworking and furniture industry was investigated. The machining conditions were determined to obtain the lowest Rz value. The experiments were carried out at the speeds of 8000, 12000, and 16000 rpm and the feed rates of 1000, 1500, and 2000 mm/min with 3 and 4 machining layers by using two different cutters with a diameter of 8 mm. Rz measurements were made on the obtained surfaces using the needle scanning method according to TS EN ISO 21920-2 (2021). In the measurements perpendicular to the fibers, the lowest Rz values were obtained with cutter type 2 (the cutter of the three cutting edge straight end mill), at 16000 rpm speed, 1000/2000 mm/min feed rate, and four machining layers. In the measurements made parallel to the fibers, the lowest Rz values were obtained at the cutter type 2 (the cutter of the three cutting edge straight end mill), at the speed of 16000 rpm and the feed rate of 1000/2000 mm/min and 4th step-down. A smooth surface (lower Rz value) was obtained with fourth cuts (step down, cut layer) instead of third cuts.

In this study, specimens from Scots pine (Pinus sylvestris L.), Anatolian chestnut (Castanea sativa Mill.) and Eastern beech (Fagus orientalis Lipsky) tree species, prepared according to ISO 3129, were conditioned according to TS ISO 13061-1. Cellulosic varnish, water-based varnish, and glass polish varnish were applied to their surfaces in accordance with ASTM-D 3023 principles. In the study, roughness (TS 2495 EN ISO 3274 and TS EN ISO 21920-3) and gloss (according to TS EN ISO 2813) values of the samples were calculated after hot and cold check test. Varnished test specimens prepared in 100 mm × 100 mm ×10 mm dimensions were first kept in drying oven at (50±5) °C for 1 hour, then were kept in conditioning room for 1 hour, and then at (-20±2) °C for 1 hour, according to ASTM D1211-97. These processes were accepted as one cycle, and tests were continued until 15 cycles. Afterward, glossiness was measured as perpendicular and parallel to fibers at 60º with a gloss measurement device, and surface roughness values of Ra and Rz were determined with a surface roughness measuring device. According to the results obtained, Scots pine (Pinus sylvestris L.), Eastern beech (Fagus Orientalis Lipsky), and Anatolian chestnut (Castanea sativa Mill.) varnish-coated wood material surfaces all showed a decrease in gloss values after hot-cold shock effect. While an increase occurred in Rz values of roughness for all wooden surfaces, Ra values roughness increased for Scots pine and chestnut and decreased for eastern beech. Gloss and roughness values of surface-treated wood materials against changing weather conditions can determine usefulness of the surface material used. The findings obtained in this study can be useful to manufacturers who use wooden products in the design of marine vehicles and those who export furniture to countries in different climatic conditions.

The main objective of this study is to determine optimum cutting parameters in order to specify the effect of densification by compressing on the processing properties of solid wood material and to achieve the best surface quality in materials densified at different rates. In line with this goal, the widely grown and low-density black poplar (Populus nigra) tree species were selected as the experimental material. Samples, which were compressed and densified by Thermo-Mechanical method at 0 %, 20 % and 40 % ratios, were processed at 1000 mm/min, 1500 mm/min and 2000 mm/min feed speeds and in 12000 rpm, 15000 rpm, 18000 rpm rotation speed on a computer numerical control machine by using two different cutters. Surface roughness values (Ra and Rz) were measured in order to evaluate surfaces obtained. Smoother surfaces were obtained in computer numerical control machining of densified samples. The lowest surface roughness values occurred in 40 % densified samples, which were the densest. The lowest surface roughness was obtained when 40 % densified samples were processed with cutter no.1 (two-flutes straight end mill), at 1000 mm/min feed speed and at 18000 rpm. Ra and Rz roughness values increased with the increase of the feed rate.

In the manufacturing of polymeric microfluidic devices, micro-molds play a key role because they determine not only the manufacturing cost but also the quality of the molded parts. Recently, a high-quality aluminum alloy 6061 (AA6061) mold with fine features less than its grain size has been fabricated economically by a hot embossing technique. However, temperature cycling during hot embossing process in mold manufacturing reduces significantly the original tensile strength and hardness of the AA6061-T6 alloy substrate, which is not desirable. In this study, a tempering process is carried out to recover the tensile strength and hardness of the embossed mold. To evaluate the changes of these properties, surface roughness, tensile strength, and hardness values were measured in each stage: (1) before hot embossing, (2) after hot embossing, and (3) tempering to T4 and tempering to T6. The results obtained demonstrate that the original strengths and hardness can be fully recovered by a posttempering process after hot embossing, but with an increase in surface roughness. Moreover, accelerated testing was carried out to evaluate the changes in hardness and roughness of AA6061-T4 and T6 molds under the typical hot embossing temperature cycles of manufacturing polymeric devices. The results obtained indicate that these temperature cycles have only a minor effect on the roughness of both T4 and T6 molds and will increase the hardness of T4 molds to T6 temper, and have negligible effect on the hardness of a T6 temper mold.

Rock is a complicated material because of the inherent heterogeneity in mineral phases and composition, even when extracted from the same rock mass. The spatial variability in compositional and structural features prevent reproducible measurements of deformation, fracture formation and other physical and chemical properties. Here, we use geo-architected 3D printed synthetic gypsum rock to show that mineral texture orientation governs the isotropy or anisotropy in fracture surface roughness and volumetric flow rate through tensile fractures. Failure load is governed by the orientation of depositional layering relative to loading direction but this effect can be hidden when an orientated mineral texture is present within the layers. We find that samples with certain mineral orientations are twice as strong as the weakest samples and that high values of sample strength correlate with rougher fracture surfaces. Mineral texture oriented parallel to the failure plane gives rise to anisotr...

In mold making, the mold surface roughness directly affects the surface roughness of the produced part. To achieve surface roughness below 0.8 μm, the cost of surface finish is high and time-consuming. One alternative to the different grinding and polishing steps is laser polishing (LP). This study investigates and models the LP of tool steel (X38CrMoV5-1-DIN 1.2343), typical for the mold industry, having an initial rough surface obtained by electrical discharge machining. The microstructures of the re-melted layer and heat-affected zone due to the LP process were also studied. Four parameters: the laser spot size, velocity, maximum melt pool temperature and overlapping were investigated via a design of experiments (DoE) approach, specifically a factorial design. The responses were line roughness (Ra), surface roughness (Sa), and waviness (Wa). The surface topography was measured before and after the LP process by white light profilometer or confocal microscopy. DoE results showed t...

The squeeze film behavior of MEMS torsion mirrors is modeled, analyzed and discussed. Effects of gas rarefaction (first-order slip-flow model with non-symmetric accommodation coefficients, ACs) and surface roughness are considered simultaneously by using the average Reynolds type equation (ARTE). Based on the operating conditions with small variations in film thickness and pressure, the ARTE is linearized. A coordinate transformation, by stretching or contracting the axes by referring to the roughness flow factors, is proposed to transform the linearized ARTE into a diffusion type modal equation. The dynamic coefficients (stiffness and damping coefficients) are then derived and expressed in analytical form. The results show that the tilting frequency (or C 0 squeeze number), roughness parameters (c Peklenik numbers, r standard deviation of composite roughness) and gas rarefaction parameters (D inverse Knudsen number, a 1 ; a 2 : ACs) are all important parameters on analyzing the dynamic performance of MEMS torsion mirrors.

In this paper, a study on surface roughness model when hole turning SAE 420 steel has been done. This study has been presented with three main contents. The first content is to determine the influence of some parameters on the surface roughness. The second content is to build a quadratic model showing the relationship between surface roughness with cutting velocity, depth of cut, feed rate and nose radius. The third content is to evaluate the accuracy of surface roughness model by comparing the roughness value when estimating and roughness value when testing. The development directions for further studies are also mentioned in this study.

AbstractA numerical model of turbulent bottom boundary layer over rough bed under irregular waves is reviewed. The turbulence model is based upon Shear Stress Transport (SST) k- model. The non-linear governing equations of the boundary layer for each turbulence models were solved by using a Crank-Nicolson type implicit finite-difference scheme. Typical the main velocity distribution, turbulence kinetic energy and time series of the bottom shear stress are presented. These results are shown to be in generally good agreement with experimental result. The roughness effects in the properties of turbulent bottom boundary layer for irregular waves are also presented with several values of the roughness parameter (a m /k s ) from a m /k s =5 to a m /k s =3122. The roughness effect tends to decrease the main velocity distribution and to increase the turbulent kinetic energy in the inner boundary layer, whereas in the outer boundary layer, the roughness alters the mean velocity distribution and the kinetic energy turbulent is relatively unaffected. The effect of bed roughness on the bottom shear stress under irregular waves is found that the higher roughness elements increase the magnitude of bottom shear stress along wave cycle. And further, the bottom shear stress under irregular waves is examined with the existing calculation method and the newly proposed method. Keywordsbottom shear stress, irregular wave, rough bed, turbulent bottom boundary layer

Three alumina-based composites were fabricated by die compaction followed by sintering. The porous microstructure was analyzed by SEM (Scanning Electron Microscopy) and EDS (Energy Dispersive X-Ray). In order to know the variation in surface roughness parameters (Ra, Rz, Rmax) of alumina composites the surface roughness of the samples was measured using a three-dimensional laser surface roughness analyzer. The microhardness values of the composites were evaluated using Vickers microhardness tester.

Three alumina-based composites were fabricated by die compaction followed by sintering. The porous microstructure was analyzed by SEM (Scanning Electron Microscopy) and EDS (Energy Dispersive X-Ray). In order to know the variation in surface roughness parameters (Ra, Rz, Rmax) of alumina composites the surface roughness of the samples was measured using a three-dimensional laser surface roughness analyzer. The microhardness values of the composites were evaluated using Vickers microhardness tester.