Characterization Of Surface Topography Research Articles

Characterization of surface irregularities and fatigue strength evaluation of wire arc additive manufactured high strength steel specimens

Characterization of surface irregularities and fatigue strength evaluation of wire arc additive manufactured high strength steel specimens

The Effects of Short-Range Intermolecular Repulsive Forces on Hamaker Constant Estimation Using Atomic Force Microscopy.

The atomic force microscope (AFM), as it is able to characterize surface topography as well determine the AFM cantilever tip-surface force, proves effective at estimating the value of the Hamaker constant, A, for a given solid material. Two main AFM-based methods have been proposed for estimating values of A. In the approach-to-contact (AtC) method, Hamaker constants are inferred from the deflections at which the AFM tip first jumps into contact with the substrate. In the pull-off (PO) method, the deflections that arise when the AFM tip is finally pulled away from the substrate are used to estimate values of A. In prior applications of these two methods, the short-range intermolecular repulsive forces that are known to arise between the AFM tip and the substrate were, however, ignored. Upon invoking a physically relevant description of these short-range and steeply repulsive forces, we investigate the effects of repulsive interactions on the values of A estimated from the existing AtC and PO methods when applied to neutrally charged systems under low humidity or vacuum conditions. For experimentally relevant surfaces, we find that repulsive forces have a modest effect on the AtC method, although they still need to be accounted for in order to generate improved estimates of the Hamaker constant. On the other hand, repulsive forces have a significant effect on the Hamaker constants inferred from the PO method, and must be properly accounted for when using this approach. Our analysis also includes an explicit incorporation of surface roughness into the PO method, which is not typically done in most prior applications of the PO method.

Characterization and correlation analysis of surface topography in ball-end milling

Abstract Surface texture is the most commonly used parameter for the quantitative characterization of surface topography. It is important for the study of the topography characteristics and functional properties of surfaces. In this paper, the surface topography characteristics, surface texture parameters, and change rule of the bearing area curve when the cutting vibration of the adjacent teeth of the ball-end milling cutter is asymmetric were analyzed, and the correlation between the inflection points and the surface texture parameters of the bearing area curve were studied according to the improved correlation analysis model. This study provides essential insights into the mechanism that drives the formation of the surface topography of ball-end milling and the intrinsic characteristic laws of the surface topography.

Quantitative Characterization of Surface Topography Using an Improved Deterministic Method

Quantitative Characterization of Surface Topography Using an Improved Deterministic Method

Image Contrast and Spectral Transmission of Presbyopia-Correcting Intraocular Lenses: Evaluating the Impact of Nd:YAG Laser Associated Defects

Purpose Neodymium yttrium aluminum garnet (Nd:YAG) laser capsulotomy is considered gold standard in the treatment of posterior capsule opacification (PCO). In this laboratory study, we measured spectral transmission to evaluate the image contrast and analyze the impact of Nd:YAG associated defects in presbyopia-correcting intraocular lenses (IOLs). Methods Two hydrophobic, acrylic IOLs as classic multifocal lenses with diffractive ring segments and different amount of near addition (A, B), one hydrophilic, trifocal IOL (C), one sector-shaped, plate haptic IOL (D) and one hydrophobic, enhanced depth of focus (EDOF) IOL (E) were studied. Measurements included surface topography characterization, United States Air Force resolution test chart (USAF) analysis, spectral transmittance measurements and through focus contrast measurement. Measurements were done with unaltered samples, damages (n = 7) were intentionally created in the central 3.5 mm zone using a photodisruption laser (2.0 mJ) and measurements were repeated. Results Significant differences were shown between unmodified samples and samples with YAG pits. The YAG-pits decreased the image contrast and spectral transmission and changed results of USAF test images. The imaging contrast decreased to 66%, 64%, 60%, 52% and 59% with the YAG shots in samples (A-E). The light transmission decreased to 88%, 87%, 92%, 79% and 91% (A-E) on average between 400 nm to 800 nm. In all IOLs a reduction of the relative intensity of transmitted light was observed. Conclusion The image performance of all tested presbyopia-correcting IOLs is significantly influenced and disturbed by YAG-pits. The intensity of transmitted light is reduced in the wavelength between 450–800 nm. USAF test targets show worse results compared to unmodified samples and contrast is significantly deteriorated. No ranking/rating among tested IOLs should be made as many other factors play a role in real world scenario. High care should be taken when performing Nd:YAG capsulotomy on premium IOLs to avoid any damages.

High-resolution coherence scanning immersion interferometry for characterization of technical surface topographies

Zusammenfassung Die Kohärenz-Scanning- Interferometrie ist eine berührungslose optische Messmethode zur hochauflösenden dreidimensionalen Charakterisierung von Oberflächentopographien. Um die laterale Auflösung eines Interferenzmikroskops zu verbessern, wurde erstmals ein Linnik-Interferometer mit hochaperturigen Immersionsobjektiven aufgebaut und zur Messung technischer Oberflächen eingesetzt. Diese Studie zeigt den Einfluss eines Immersionsmediums zur Verbesserung der lateralen Auflösung und vergleicht Immersions- und Nicht-Immersionssysteme in Bezug auf Signalbildung und Übertragungsverhalten im dreidimensionalen Ortsfrequenzraum. Die Messergebnisse von transparenten AMONIL®-Gittern zeigen eine signifikante Verbesserung der Signalqualität im Vergleich zum Nicht- Immersionssystem. Außerdem werden Messergebnisse von Halbkugeln vorgestellt, die durch Substrate Sonformal Imprint Lithography substrukturiert wurden.

Preparation of measured engineering surfaces for modeling tribological systems, part I: Characterization and reconstruction

Preparation of measured engineering surfaces for modeling tribological systems, part I: Characterization and reconstruction

Evaluation of high-frequency roughness measurement errors for composite and ceramic surfaces after machining

Evaluation of high-frequency roughness measurement errors for composite and ceramic surfaces after machining

Two 3D Fractal-Based Approaches for Topographical Characterization: Richardson Patchwork versus Sdr.

Various methods exist for multiscale characterization of surface topographies, each offering unique insights and applications. The study focuses on fractal-based approaches, distinguishing themselves by leveraging fractals to analyze surface complexity. Specifically, the Richardson Patchwork method, used in the ASME B46.1 and ISO 25178 standards, is compared to the Sdr parameter derived from ISO 25178-2, with a low-pass Gaussian filter for multiscale characterization. The comparison is performed from the relative area calculated on topographies of TA6V samples grit blasted with different pressures and blasting materials (media). The surfaces obtained by grit blasting have fractal-like characteristics over the scales studied, enabling the analysis of area development at multiple levels based on pressure and media. The relative area is similar for both methods, regardless of the complexity of the topographies. The relevance scale for each calculation method that significantly represents the effect of grit blasting pressure on the increased value of the relative area is a tiling of 7657.64 µm² of triangle area for the Patchwork method and a 124.6 µm cut-off for the low-pass Gaussian filter of the Sdr method. These results could facilitate a standard, friendly, new fractal method for multiscale characterization of the relative area.

Multiscale analysis of hierarchical flax-epoxy biocomposites with nanostructured interphase by xyloglucan and cellulose nanocrystals

Multiscale analysis of hierarchical flax-epoxy biocomposites with nanostructured interphase by xyloglucan and cellulose nanocrystals

Surface topography characterization of USMM during machining of zirconia ceramic using silicon carbide abrasives: An experimental and simulation approach

Surface topography characterization of USMM during machining of zirconia ceramic using silicon carbide abrasives: An experimental and simulation approach

A methodology for the 3D characterization of surfaces using X-ray computed tomography: Application to additively manufactured parts

A methodology for the 3D characterization of surfaces using X-ray computed tomography: Application to additively manufactured parts

Influence of manufacturing surface topography on torque and load bearing capacity of hydro-viscous drive clutch under mixed lubrication stage

PurposeHydro-viscous drive (HVD) clutches are widely used in equipment requiring soft start, such as fans and pumps, to transmit torque and adjust speed by changing the gap distance between friction pairs. This paper aims to propose a novel two-parameter evaluation method for HVD during the mixed lubrication stage. The objective is to develop an effective model that establishes the relationship between these parameters and the actual surface topography.Design/methodology/approachIn the presented methods, the fractal features of the real manufacturing surface are calculated based on the power spectrum function by the ultra-depth three-dimensional microscope. After that, the hybrid friction model of the friction plate is established based on mixed elasto-hydrodynamic lubrication theory, boundary friction model and fractal theory. Then the torque and load bearing characteristics of the clutch are obtained, and the influences of the surface fractal features are investigated and discussed. Finally, the Weierstrass–Mandelbrot function is adopted for the surface topography characterization and evaluation.FindingsThe results indicate that the proposed method exhibits good accuracy, while the speed difference between the friction pair exceeds 2,500 rpm. It is concluded that this paper proposed a way to evaluate the torque and loading capacity of HVD considering the real manufacturing surface topography and is helpful for surface optimization.Originality/valueThe originality and value of this study lie in its development of a novel torque and load bearing capacity evaluation method for HVD in mixed lubrication stage, considering manufacturing surface topography and describing the real manufacturing surface.

Influence of a cutting fluid on the surface integrity and fatigue strength of 42CrMo4 drilled parts.

Influence of a cutting fluid on the surface integrity and fatigue strength of 42CrMo4 drilled parts.

Small Unmanned Aircraft Systems and Agro-Terrestrial Surveys Comparison for Generating Digital Elevation Surfaces for Irrigation and Precision Grading

Advances in remote sensing and small unmanned aircraft systems (sUAS) have been applied to various precision agriculture applications. However, there has been limited research on the accuracy of real-time kinematic (RTK) sUAS photogrammetric elevation surveys, especially in preparation for precision agriculture practices that require precise topographic surfaces, such as increasing irrigation system efficiency. These practices include, but are not limited to, precision land grading, placement of levees, multiple inlet rice irrigation, and computerized hole size selection for furrow irrigation. All such practices rely, in some way, on the characterization of surface topography. While agro-terrestrial (ground-based) surveying is the dominant method of agricultural surveying, aerial surveying is emerging and attracting potential early adopters. This is the first study of its kind to assess the accuracy, precision, time, and cost efficiency of RTK sUAS surveying in comparison to traditional agro-terrestrial techniques. Our findings suggest sUAS are superior to ground survey methods in terms of relative elevation and produce much more precise raster surfaces than ground-based methods. We also showed that this emergent technology reduces costs and the time it takes to generate agricultural elevation surveys.

Detailed evaluation of topographical effects of Hirtisation post-processing on electron beam powder bed fusion (PBF-EB) manufactured Ti-6Al-4V component

Detailed evaluation of topographical effects of Hirtisation post-processing on electron beam powder bed fusion (PBF-EB) manufactured Ti-6Al-4V component

Roughness evaluation of turned composite surfaces by analysis of the shape of autocorrelation function

Roughness evaluation of turned composite surfaces by analysis of the shape of autocorrelation function

Influence of Surface Contaminants and Hydrocarbon Pellicle on the Results of Wettability Measurements of Titanium.

Hydrophilicity/hydrophobicity-or wettability-is a key surface characterization metric for titanium used in dental and orthopedic implants. However, the effects of hydrophilicity/hydrophobicity on biological capability remain uncertain, and the relationships between surface wettability and other surface parameters, such as topography and chemistry, are poorly understood. The objective of this study was to identify determinants of surface wettability of titanium and establish the reliability and validity of the assessment. Wettability was evaluated as the contact angle of ddH2O. The age of titanium specimens significantly affected the contact angle, with acid-etched, microrough titanium surfaces becoming superhydrophilic immediately after surface processing, hydrophobic after 7 days, and hydrorepellent after 90 days. Similar age-related loss of hydrophilicity was also confirmed on sandblasted supra-micron rough surfaces so, regardless of surface topography, titanium surfaces eventually become hydrophobic or hydrorepellent with time. On age-standardized titanium, surface roughness increased the contact angle and hydrophobicity. UV treatment of titanium regenerated the superhydrophilicity regardless of age or surface roughness, with rougher surfaces becoming more superhydrophilic than machined surfaces after UV treatment. Conditioning titanium surfaces by autoclaving increased the hydrophobicity of already-hydrophobic surfaces, whereas conditioning with 70% alcohol and hydrating with water or saline attenuated pre-existing hydrophobicity. Conversely, when titanium surfaces were superhydrophilic like UV-treated ones, autoclaving and alcohol cleaning turned the surfaces hydrorepellent and hydrophobic, respectively. UV treatment recovered hydrophilicity without exception. In conclusion, surface roughness accentuates existing wettability and can either increase or decrease the contact angle. Titanium must be age-standardized when evaluating surface wettability. Surface conditioning techniques significantly but unpredictably affect existing wettability. These implied that titanium wettability is significantly influenced by the hydrocarbon pellicle and other contaminants inevitably accumulated. UV treatment may be an effective strategy to standardize wettability by making all titanium surfaces superhydrophilic, thereby allowing the characterization of individual surface topography and chemistry parameters in future studies.

A mixed-lubricated friction model of water lubricated bearing based on fractal theory

To the water lubricated bearing, its mixed-lubricated friction model is generally established based on the traditional statistical model, whose accuracy is not high due to the inaccurate characterization of surface topography. Therefore, this paper employs the fractal theory that has scale-independent characteristics and high precision to characterize the surface topography of the bearing and journal, and then establishes the fractal contact model of asperity, combining the average Reynolds equation of the film, proposes a mixed-lubricated friction model based on fractal theory. The scanning experiments of surface topography are carried out to obtain the fractal parameters and measurements of the friction coefficient are performed to verify the effectiveness of the proposed mixed-lubricated model. Subsequently, the proposed mixed-lubricated friction model is employed to analyze the effects of the number of groove, the position of groove and the fractal parameters on the lubrication and friction characteristics of the water lubricated bearing. Results indicate when the grooves are in the non-main load-carrying regions, the friction characteristics of the bearing slightly changes, and the lower surface roughness is beneficial to improve the lubrication and friction properties of the bearing.

Image Contrast and Spectral Transmission in Intraocular Lenses with Nd:YAG Pits

Purpose Neodymium yttrium aluminum garnet (Nd:YAG) laser capsulotomy is considered as safe and effective method in the treatment of posterior capsule opacification. Nevertheless, side effects are described. The incorrectly adjusted focus of the laser beam during the procedure can lead to so-called YAG-pits or YAG-shots. In this experimental study, we measured spectral transmission to evaluate the image contrast and analyze the impact of YAG-pits in intraocular lenses (IOL). Methods Acrylic, foldable, one-piece IOLs with 6.0 mm optic and different material properties were studied. These included: monofocal IOLs and enhanced monofocal IOLs with water content of 0.3%, 26.0%, and 4.0% and a refractive index of 1.49, 1.46, and 1.54, respectively. All measurements were done with new, unaltered IOLs and IOLs with YAG-pits. Damage was intentionally created, performing YAG-pits (n = 7) in the central zone (3.5 mm) using a photodisruption laser (2.0mJ). All laboratory measurements were repeated: These included surface topography characterization, United States Air Force (USAF) resolution test chart analysis, spectral transmittance measurements and through focus contrast measurement. Results Significant differences were found between the unaltered lenses and lenses with defects. The YAG-pits within the optic of the IOLs decreased the image contrast and spectral transmission and changed results of USAF test images at the focal position by 62%, 57% and 54%, respectively. In all IOLs a reduction of the relative intensity of total transmitted light was observed between 450 and 700 nm wavelength. Conclusion This experimental study confirmed that the IOL image performance deteriorates with YAG-pits. The total intensity of transmitted light or transmittance (without scattering) was reduced in the wavelength between 450 and 700 nm. The contrast was significantly reduced and USAF test targets showed much worse results compared to unmodified counterparts. There was no systematic difference between monofocal and enhanced monofocal lenses. Further experiments should investigate the effect of YAG-pits on diffractive IOLs.