Surface Topography Parameters Research Articles

Thoracic Idiopathic Scoliosis: Establishing the Diagnostic Accuracy and Reference Values of Surface Topography

Objective: The aim of this study was to establish the diagnostic accuracy and cut-off points of the surface topography parameters.

Microscopic analysis of the Sol-Gel alumina grinding wheel after the introduction of a synthetic organosilicon polymer-based impregnate dedicated for near dry grinding processes

In the paper, analysis of the surface condition of 1-35 × 10 × 10-SG/ F46G10VTO grinding wheels with microcrystalline sintered alumina abrasive grains and a glass-crystalline bond after the impregnation process using a synthetic organosilicon polymer (silicone) has been presented. The main goal was to compare the values of selected surface topography parameters obtained from the active surfaces of an impregnated set of grinding wheels with those same parameters obtained from a non-impregnated reference wheel. The analysis proved that an elaborated method of introducing the impregnating substance is effective and allowing to uniformly its distribution throughout the body of the grinding wheel. However, the introduction of impregnating substance caused a reduction (average from 13% to 50%) in the values of the selected 3D parameters of grinding wheel active surface (GWAS) roughness. An analysis described in this work is the basis of an objective evaluation of the experimental results of the grinding process conducted with use of that kind of wheels.

Characterization of surface texture in electropolishing processes using 3D surface topography parameters

Surface engineering requires new technology for the evaluation of surface texture. Profiling methods for the characterization of surface finish do not permit the detailed analysis of surface microgeometry. Thus, advances in the field of surface metrology have led to the development of topographic profilometer systems capable of the three-dimensional topographical reconstruction of real surface texture using phase shift scanning of surfaces, with instruments able to measure microgeometric form, waviness, and roughness, individually or integrated. The innovative three-dimensional evaluation methods, using contact and non-contact technology, enable the virtual reconstruction of surfaces for the evaluation of area roughness parameters, three-dimensional topographic maps with color scale, and profiling of sections in any area of a surface to provide the two-dimensional roughness parameters, among others. In this study a set of 3D surface parameters were analyzed: fractal analysis, area roughness parameters (Sa, Sz, and Spd), and three-dimensional surface topography, in order to determine the information provided by each in the analysis of surface texture. The topographic analysis performed detected deformations on the borders of the workpieces when high electropolishing times and current densities were combined, due to the lack of homogeneity in the elimination of the treated surface material. Finally, this study has determined electropolishing conditions and electrolytic effects on surface texture using the three-dimensional analysis of surface texture.

Three-Dimensional, Bifunctional Microstructured Polymer Hydrogels Made from Polyzwitterions and Antimicrobial Polymers.

Biofilm-associated infections of medical devices are a global problem. For the prevention of such infections, biomaterial surfaces are chemically or topographically modified to slow down the initial stages of biofilm formation. In the bifunctional material here presented, chemical and topographical cues are combined, so that protein and bacterial adhesion as well as bacterial proliferation are effectively inhibited. Upon changes in the surface topography parameters and investigation of the effect of these changes on bioactivity, structure-property relationships are obtained. The target material is obtained by microcontact printing (μCP), a soft lithography method. The antimicrobial component, poly(oxanorbornene)-based synthetic mimics of an antimicrobial peptide (SMAMP), was printed onto a protein-repellent polysulfobetaine hydrogel, so that bifunctional 3D structured polymer surfaces with 1, 2, and 8.5 μm spacing are obtained. These surfaces are characterized with fluorescence microscopy, surface plasmon resonance spectroscopy, atomic force microscopy, and contact angle measurements. Biological studies show that the bifunctional surfaces with 1 and 2 μm spacing are 100% antimicrobially active against Escherichia coli and Staphylococcus aureus, 100% fibrinogen-repellent, and nontoxic to human gingival mucosal keratinocytes. At 8.5 μm spacing, the broad-band antimicrobial activity and the protein repellency are compromised, which indicates that this spacing is above the upper limit for effective simultaneous antimicrobial activity and protein repellency of polyzwitterionic-polycationic materials.

Comparison of selected surface topography parameters after the turning of Inconel 625 obtained by the additive techniques to the parameters of the material made by the traditional techniques

Abstract The paper presents the possibilities of additive manufacturing of the selected alloy, Inconel, for production of ready-made elements. The results of surface topography examination of the material manufactured with the use of the device 557 RPMI working in the LDT technology (LDT = Laser Deposition Technology) have been compared to those of thecold drawn material. The surfacejust after manufacturing inthese two technologies has been compared to the one after machining by means of variable machining parameters. The surface roughness parameter, Sskis positive for all the surfaces of thesamplemade by the traditional technology, regardless of the feed. This means that most of the material is located close to the valleys. The surfaces are characterised by right-hand side asymmetry. In all the surfaces of the sample made by the additive technology, regardless of the feed value, the surface roughness parameter, Ssk, is negative, which means that most of the material is located close to the peaks.

Application Of The Hamming Network To The Classification Of Surfaces After Abrasive Machining

The use of artificial neural networks for modelling and inference about surface parameters is a more and more often undertaken research topic. Based on the analysis of the ranges of suitability of surface topography parameters, a variety of different parameters can be observed to identify surfaces with different features and different conditions of use. The issues of surface topography analysis and determination of surface condition after abrasive machining are of fundamental importance. Currently, when assessing the surface intended for interaction with the other surface, it is possible to use many surface evaluation parameters. Assigning the machined surface to the appropriate assessment group, especially in automated quality control systems, requires a preliminary surface classification. In this article Hamming's network was used for the surface classification along with modification of Hamming distance.

3D numerical wear model for determining the change in surface topography

Micropitting and related surface fatigue mechanisms are influenced by the running-in behavior of contacting bodies subjected to rolling/sliding motion. The running-in of contacting surfaces results in significant change in many surface topography parameters, such as mean summit radius, the radius of individual summits, and standard deviation of summit height, which leads to contact pressure, real contact area, and plasticity index. In this work, running-in wear is simulated by developing a 3D numerical wear model. The simulation is performed on 3D rough surfaces having different skewness and kurtosis. It is shown that mean summit radius and radius of the individual summit are strongly influenced and significantly vary during wear process. It is found that a change in contact pressure and plasticity index can be related to a single topography parameter. The objective of this work is to show the topography parameters variation during running-in wear, which is hitherto not discussed elsewhere in detail. The variation with the number of cycles for roughness parameters determined from wear experiment and simulation are compared and a good match is found.

Analiza rozmieszczenia kieszeni olejowych w pomiarach struktury geometrycznej powierzchni

In this paper the influence of distribution of oil pockets on areal form removal in surface topography measurement was taken into consideration. Surface topography of plateau-honed cylinder liners with burnished oil pockets was analyzed. The effect of dimples distribution on surface topography parameters (from ISO 25178 standard) after form removal by commonly used algorithms (cylinder fitted by the least square method, polynomials of nth degree, robust Gaussian filter) and/or other procedures (plateau-part filtering method, digital extraction of valleys) was taken into account.

Wpływ rozdzielczości pionowej na błędy pomiaru topografii obrabianych powierzchni

The effect of the quantization error on values of surface topography parameters was examined. Surface topography was measured using an optical profilometer of 0.01 nm vertical resolution. Twenty isotropic and anisotropic, one- and two-process, random and deterministic surfaces were objects of investigations. The vertical resolution was changed using TalyMap software. Tendencies of changes of three surfaces due to quantization errors were analyzed in details. Parameters of the highest and the smallest sensitivity on errors were selected.

Glacier branch lines and glacier ice thickness estimation for debris-covered glaciers in the Central Tien Shan

ABSTRACTInformation about the ice volume stored in glaciers is of high importance for sustainable water management in many arid regions of Central Asia. Several methods to estimate the ice volume exist. However, none of them take the specific characteristics of flat terminus debris-covered glaciers into account. We present a method for deriving spatially-distributed ice thickness for debris-covered dendritic glaciers, which are common not only in Central Tien Shan but also in several other mountain ranges in High Asia. The method relies on automatically generated branch lines, observed surface velocities and surface topographic parameters as basic input. Branch lines were generated using Thiessen polygons and Dijkstra's path algorithm. Ice thicknesses for four debris-covered glaciers – South Inylchek, Kaindy, Tomur and Koxkar glaciers – have been estimated along the branch line network solving the equation of laminar flow. For Koxkar and South Inylchek glaciers, respectively, maximum thicknesses of ~250 and 380 m were estimated. These results differ by ~50 m compared with GPR measurements with an uncertainty for the debris-covered parts of ~40%. Based on geodetic mass balances, we estimate that the investigated glaciers lost between 6 and 28% of their volume from 1975 to the early 2000s.

Preparation of superhydrophobic and superoleophobic Al–Mg alloy surface via simple, environmentally friendly method

Abstract

Problem of selection of reference plane with deep and wide valleys analysis

Areal form removal of cylindrical surfaces containing deep and wide valleys was often analysed; the influence of selection of filtering techniques was taken into consideration in many original researches. However, the errors of reference plane selection on surface topography parameters of cylindrical elements containing deep and wide dimples (oil pockets, scratches) were not fully recognized. In this paper, the improper selection of reference plane in surface topography analysis of cylindrical elements with deep or wide oil pockets were taken into consideration. The errors of surface topography parameters (from ISO 25178 standard) caused by improper areal form removal were presented; some parameters were specified according to its the biggest distortions. It was proposed to select the reference plane with particular attention to the specified parameters. It was assumed that proposal of bandwidth (cut-off) values in digital filtering depends on both size and distance between dimples.

Proposal of edge-area form removal of cylindrical surfaces containing wide dimples by application of various robust processing techniques

Surface topography parameters of car engine elements (cylinder liners, piston skirts) are usually calculated after form removal. There are many algorithms dedicated for selection of reference plane in surface topography analysis. However, areal form removal of cylindrical surfaces containing deep or wide valleys (oil pockets, scratches) was not fully recognized when the dimples were edge-situated. Moreover, application of some robust techniques not always provided a reasonable results in areal form removal for surfaces with small (less than dimples diameter value) oil pocket distances. In this paper some digital filtering techniques were proposed for minimization of reference plane distortion when cylindrical elements contained deep and wide valleys with near-edge distribution. It was assumed, that application of commonly used robust techniques caused the distortion of deep or wide near-edge dimples; some of the proposed digital processing algorithms provided a better edge-filtering results.

Investigating the efficiency of a bio-inspired insect repellent surface structure

Most insects with smooth or hairy adhesive pads have very little problems in attaching to smooth substrates. A careful selection of surface roughness, however, can effectively limit the contact area of the adhesive organs with the surface. In comparison to conventional toxin-based insect repelling methods, biologically inspired micro- and nanostructured insect repellent surface structures, thus, offer a great potential to effective and environmentally-friendly control insect pests.We here present a simple experimental approach to qualitatively and quantitatively analyse the efficiency of a micro- and nanorough surface structure. Nauphoeta cinerea and Gastrophysa viridula as model organisms for insects with smooth and hairy adhesive pads, respectively, were placed in an enclosed environment. The escape movements of freely running insects over either the repellent or a control surfaces were counted and analyzed in detail. The tested surface structures were able to significantly reduce the escape of cockroaches with smooth adhesive pads by 44.1%. Interestingly, the data indicates that N. cinerea might use mechanical cues from the antenna to discriminate between surfaces before making contact with the adhesive pads. G. viridula with hairy adhesive pads were not significantly affected by the surface structure.By carefully adjusting ‘critical’ surface topography parameters relevant for insect adhesion, more efficient and selective repellent surfaces might be achieved. Such nanostructure-based insect repellent surfaces could also help to utilize recruitment behavior of certain insect species and might present a novel approach to effectively control insect pests.

Predicting running-in wear volume with a SVMR-based model under a small amount of training samples

Abstract This paper proposes a support vector machine regression (SVMR) model to predict running-in wear volume, with field surface topography parameters and working conditions as the input variables, under the condition that the amount of training samples is very limited. Experimental results proved the effectiveness of the SVMR-based model with a small amount of training samples. Based on the established prediction model, the impacts of the field surface parameters on running-in wear volume have been analyzed. The results show that Sku has the largest influence on running-in wear volume, Sdq the second, and Svk the least.

Wettability of laser textured surface: a parametric study based on numerical simulation and experimentation

PurposeDynamic spreading and wetting on the rough surfaces is complicated, which directly affects the fluxion and phrase transition properties of the fluid. This paper aims to enhance our knowledge of the mechanism of micro-texture lubrication from interface wettability and provide some guidance for the practical manufacturing of the surfaces with special wettability and better lubrication characteristics.Design/methodology/approachThe effect of surface topography on the wetting behavior of both smooth and rough hydrophilic surfaces was investigated using a combination of experimental and simulation approaches. Four types of patterns with different topographies were designed and fabricated through laser surface texturing. The samples were measured with a non-contact three-Dimensional (3D) optical profiler and were parameterized based on ISO 25178. Quantitative research on the relevancy between the topography characteristic and wettability was conducted with several 3D topography parameters.FindingsResults show that for the surfaces with isotropic textures, topography with a small skewness (Ssk) and a large kurtosis (Sku) exhibits better wettability and spreading behavior. For the surfaces with anisotropic textures (smaller texture aspect ratio, Str), dominant textures (such as long groove, rectangle) play a significant guiding role in promoting spreading. In addition, the moving mechanism of the triple contact line and anisotropic spreading were also studied using a computational fluid dynamics simulation. The simulation results have a good adherence with the experimental results.Originality/valueMost of the surface characterization methods at present remain at a level that is related to geometric description, and the topography parameters are limited to 2D roughness parameters. So in present study, the relevancy between wettability and 3D surface topography parameters is explored. The authors believe that the current work provides a new viewpoint to the relevancy between surface topography and wettability.

Characterisation of wear areas on UHMWPE total knee replacement prostheses through study of their areal surface topographical parameters

Total knee replacement is one of the most common elective surgeries in the world, and presents a number of challenges related to the wear of ultra-high molecular weight polyethylene (UHMWPE). This paper presents an analysis of the surface topographical properties of the worn and unworn condylar surfaces on a small cohort of both wear simulated and retrieved prostheses of varying designs. A number of measurement points were taken on each prostheses in a mixture of worn and unworn areas through the use of focus-variation microscopy (FVM), a non-contact method of surface measurement. Surface areal parameters were extracted from this data to analyse and search for patterns within the data. It was found that in general, worn implant surfaces appear to show smoother, less peak dominated surfaces than unworn area. It was also found that wear simulated and retrieved implants display similar characteristics of surface topography. In addition, variation was noted between different designs of TKR device, with posterior stabilised designs found to be peak dominated and cruciate retaining type implants being valley dominated.

Surface topography and roughness of silicon carbide ceramic matrix composites

The silicon carbide ceramic matrix composite (Cf/SiC) plays an important role in aeronautic and space applications due to its excellent performance. Cf/SiC consists of silicon carbide and carbon fibers. The effects of the grinding parameters on the 3D parameters of surface roughness and surface topography when grinding 2.5D needled Cf/SiC materials have rarely been investigated. The primary purpose of this paper is to fill this knowledge gap. Cf/SiC material was ground in the direction of the orthogonal surface, and the surface topography, grinding parameters and grinding mechanism were analysed through a series of experiments. The results indicated that matrix cracks, fiber fractures, fiber wear and interfacial debonding were the primary removal methods of the material. The grinding parameters exert a substantial influence on the quality of the machined surface, primarily because of the undeformed chip thickness and the length of the contact arc. In the grinding process of the 2.5D Cf/SiC material, the quality of the surface roughness and its parameters gradually improved with increasing grinding speed, whereas the feed speed and grinding depth produced the opposite effect. Based on the conclusions, the surface topography and roughness parameters of 2.5D Cf/SiC material can be predicted, which thus provides useful technical support for increasing the machining quality of 2.5D Cf/SiC material and all its composites.

The simulation of surface topography generation in multi-pass sanding processes through virtual belt and kinetics model

Belt sanding is an effective manner of material processing and widely used to improve the surface roughness and obtain high polishing glossiness. During the belt sanding process, the contact condition exhibits more complexity than grinding due to the flexibility of the belt. For the sanding application where surface glossiness is expected, it always involves multiple sanding as well as polishing passes. This makes the analytical modeling of the surface generation as well as its impact on glossiness formation complicated in this multi-pass operation. In this paper, the surface generation model for multi-pass sanding operation is established through the development of the virtual sanding belt model and the multi-pass kinematics simulation of the sanding process. As for the belt-workpiece contact zone, the 3D Hertz contact model is incorporated into the kinematics simulation to duplicate the real contact condition for multi-pass sanding. Furthermore, the critical surface topography parameters are identified to establish the correlation with belt sanding parameters. Finally, surface topography parameters related with glossiness properties, e.g., surface roughness Sq, surface height distribution kurtosis Ku, surface height distribution skewness Sk, and surface correlation lengths Lx and Ly, are studied for optimal sanding process parameter analysis. The optimal sanding condition for ideal glossiness should be that the rotation speed should be beyond 1200 r/min, and the workpiece feedrate should be below 50 mm/s.

Effects of extreme pressure and anti-wear additives on surface topography and tool wear during MQCL turning of AISI 1045 steel

The paper presents an original study of the influence of extreme pressure and anti-wear (EP/AW) additives on the surface topography of double-phase steel during turning with different cooling media and variable flow rates. The obtained surface topographies were compared using frequency and fractal analyses for dry, minimum quantity cooling lubrication (MQCL), and MQCL + EP/AW methods. Results showed that the addition of phosphate ester-based additives to an active medium caused the formation of tribofilm on the tool-chip interface and thus a change in the lubricating properties by reducing friction. The tool wear and the formation of the thin-layered tribofilm were also incorporated. The application of the MQCL method with the EP/AW additives led to a decrease in particular surface topography parameters from 8 % to 38 % in comparison with the effects of dry cutting and from 6 % to 35 % in comparison with the effects of machining under MQCL conditions. An exception was the result obtained for the surface roughness height parameter Sp, which was higher than that obtained after the MQCL + EP/AW process for the lowest investigated feed per revolution f = 0.1 mm/rev. This observation was correlated with the uneven formation of the tribofilm on the machined surface. The phosphate ester-based additive used in the MQCL + EP/AW method contributed to achieving tool wear that was less than that obtained by the processes conducted under dry and MQCL conditions.