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Open AccessArticle

Changes in Areal Surface Textures Due to Ball Burnishing

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Materials 2023, 16(17), 5904; https://doi.org/10.3390/ma16175904 - 29 Aug 2023

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The description of the areal texture of the surface is more comprehensive than that of roughness profiles. Ball burnishing led to an improvement in surface quality. In this work, the changes in areal surface textures due to ball burnishing were studied. Three surfaces [...] Read more.

The description of the areal texture of the surface is more comprehensive than that of roughness profiles. Ball burnishing led to an improvement in surface quality. In this work, the changes in areal surface textures due to ball burnishing were studied. Three surfaces of steel, two after milling and one after grinding, were subjected to ball burnishing. In the burnishing process, the burnishing pressure and width were variable parameters. Surface topographies before and after burnishing were measured using a white light interferometer. Ball burnishing was found to lead to a decrease in surface amplitude. The highest relative reduction was 94%. The changes in roughness height were greater with a higher amplitude of the surface texture before burnishing. The hybrid parameters also decreased as a result of ball burnishing. The characteristics of changes in spatial parameters mainly depended on the surface texture before burnishing. Full article

(This article belongs to the Special Issue Surface Inspection and Description in Metrology and Tribology (Second Volume))

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Open AccessArticle

The Influence of Osteon Orientation on Surface Topography Parameters after Machining of Cortical Bone Tissue

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Materials 2023, 16(12), 4293; https://doi.org/10.3390/ma16124293 - 09 Jun 2023

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Abstract

Mechanical processing of cortical bone tissue is one of the most common surgical procedures. A critical issue accompanying this processing is the condition of the surface layer, which can stimulate tissue growth and serve as a drug carrier. A comparison of the surface [...] Read more.

Mechanical processing of cortical bone tissue is one of the most common surgical procedures. A critical issue accompanying this processing is the condition of the surface layer, which can stimulate tissue growth and serve as a drug carrier. A comparison of the surface condition before and after orthogonal and abrasive processing was conducted to validate the influence of bone tissue’s processing mechanism and orthotropic properties on the surface topography. A cutting tool with a defined geometry and a custom-made abrasive tool was used. The bone samples were cut in three directions, depending on the orientation of the osteons. The cutting forces, acoustic emission, and surface topography were measured. The level of isotropy and the topography of the grooves showed statistical differences relative to the anisotropy directions. After orthogonal processing, the surface topography parameter Ra was determined from 1.38 ± 0.17 μm to 2.82 ± 0.32. In the case of abrasive processing, no correlation was found between the orientation of osteons and topographical properties. The average groove density for abrasive machining was below 1004 ± 0.7, and for orthogonal, it was above 1156 ± 58. Due to the positive properties of the developed bone surface, it is advisable to cut in the transverse direction and parallel to the axis of the osteons. Full article

(This article belongs to the Special Issue Surface Inspection and Description in Metrology and Tribology (Second Volume))

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Open AccessArticle

Metrological Aspects of Assessing Surface Topography and Machining Accuracy in Diagnostics of Grinding Processes

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Materials 2023, 16(6), 2195; https://doi.org/10.3390/ma16062195 - 09 Mar 2023

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Abstract

The paper presents probabilistic aspects of diagnostics of grinding processes with consideration of metrological aspects of evaluation of topography of machined surfaces and selected problems of assessment of machining accuracy. The processes of creating the geometric structure of the ground surface are described. [...] Read more.

The paper presents probabilistic aspects of diagnostics of grinding processes with consideration of metrological aspects of evaluation of topography of machined surfaces and selected problems of assessment of machining accuracy. The processes of creating the geometric structure of the ground surface are described. It was pointed out that the distribution of features important for process diagnostics depends on the mechanism of cumulative effects of random disturbances. Usually, there is a multiplicative mechanism or an additive mechanism of the component vectors of relative displacements of the tool and workpiece. The paper describes a method for determining the classification ability of specific parameters used to evaluate stereometric features of ground surfaces. It is shown that the ability to differentiate the geometric structure of a certain set of surfaces using a selected parameter depends on the geometric mean of the differences in normalized and sorted, consecutive values of this parameter. A methodology is presented for evaluating the ability of various parameters to distinguish different geometric structures of surfaces. Further, on the basis of analyses of a number of grinding processes, a methodology was formulated for proceeding leading to a comprehensive evaluation of machining accuracy and forecasting its results. It was taken into account that in forecasting the accuracy of grinding, it is necessary to determine the deviations, arising under the conditions of multiplicative interaction of the effects of various causes of inaccuracy. Examples are given of processes in which, due to the deformation of the technological system, dependent on the position of the zone and machining force, varying temperature fields and tool wear, the distributions of dimensional deviations are not the realization of stationary processes. It was emphasized that on the basis of the characteristics of the dispersion of the deviation value in the sum set of elements, it is not possible to infer its causes. Only the determination of the “instantaneous” values of the deviation dispersion parameters allows a more complete diagnosis of the process. Full article

(This article belongs to the Special Issue Surface Inspection and Description in Metrology and Tribology (Second Volume))

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Open AccessArticle

Research on the Durability and Reliability of Industrial Layered Coatings on Metal Substrate Due to Abrasive Wear

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Krzysztof Przystupa

Materials 2023, 16(5), 1779; https://doi.org/10.3390/ma16051779 - 21 Feb 2023

Cited by 1 | Viewed by 587

Abstract

This paper discusses the issue of evaluating the durability and reliability of organic coatings applied on the outer surfaces of roofing sheets. Two sheets, i.e., ZA200 and S220GD, were selected as research objects. Metal surfaces of these sheets are protected with multilayer organic [...] Read more.

This paper discusses the issue of evaluating the durability and reliability of organic coatings applied on the outer surfaces of roofing sheets. Two sheets, i.e., ZA200 and S220GD, were selected as research objects. Metal surfaces of these sheets are protected with multilayer organic coatings to protect them against weather conditions, assembly, and operational damages. The durability of these coatings was tested by evaluating their resistance to tribological wear using the ball-on-disc method. The testing was conducted in reversible gear according to a sinuous trajectory at a 3 Hz frequency. The test load was 5 N. When the coating was scratched, the metallic counter sample touched the metallic surface of the roofing sheet, which indicated a significant drop in electrical resistance. It is assumed that the number of performed cycles specifies the durability of the coating. Weibull analysis was applied to examine the findings. The reliability of the tested coatings was evaluated. The tests have confirmed that the structure of the coating is essential for the durability and reliability of products. The research and analysis included in this paper present important findings. Full article

(This article belongs to the Special Issue Surface Inspection and Description in Metrology and Tribology (Second Volume))

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Open AccessArticle

Top-down Determination of Fluctuations in Topographic Measurements

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Materials 2023, 16(2), 473; https://doi.org/10.3390/ma16020473 - 04 Jan 2023

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A top-down method is presented and studied for quantifying topographic map height (z) fluctuations directly from measurements on surfaces of interest. Contrary to bottom-up methods used in dimensional metrology, this method does not require knowledge of transfer functions and fluctuations of [...] Read more.

A top-down method is presented and studied for quantifying topographic map height (z) fluctuations directly from measurements on surfaces of interest. Contrary to bottom-up methods used in dimensional metrology, this method does not require knowledge of transfer functions and fluctuations of an instrument. Fluctuations are considered here to be indicative of some kinds of uncertainties. Multiple (n), successive topographic measurements (z = z(x,y)) are made at one location without moving the measurand relative to the measurement instrument. The measured heights (z) at each position (x,y) are analyzed statistically. Fluctuation maps are generated from the calculated variances. Three surfaces were measured with two interferometric measuring microscopes (Bruker ContourGT™ and Zygo NewView™ 7300). These surfaces included an anisotropic, turned surface; an isotropic, sandblasted surface; and an abraded, heterogeneous, multilayer surface having different, complex, multiscale morphologies. In demonstrating the method, it was found that few non-measured points persisted for all 100 measurements at any location. The distributions of uncertainties are similar to those of certain features on topographic maps at the same locations, suggesting that topographic features can augment measurement fluctuations. This was especially observed on the abraded ophthalmic lens; a scratch divides the topographic map into two zones with different uncertainty values. The distributions of fluctuations can be non-Gaussian. Additionally, they can vary between regions within some measurements. Full article

(This article belongs to the Special Issue Surface Inspection and Description in Metrology and Tribology (Second Volume))

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Open AccessArticle

Parametric Characterization of Machined Textured Surfaces

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Pawel Pawlus

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Rafal Reizer

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Michal Wieczorowski

Materials 2023, 16(1), 163; https://doi.org/10.3390/ma16010163 - 24 Dec 2022

Cited by 5 | Viewed by 782

Abstract

Surface topography in general is not easy to characterize due to a great number of different features that appear on it. It is still more challenging for machined textured surfaces that are of high functional significance for tribological purposes. For practical reasons, there [...] Read more.

Surface topography in general is not easy to characterize due to a great number of different features that appear on it. It is still more challenging for machined textured surfaces that are of high functional significance for tribological purposes. For practical reasons, there is a need to describe such surfaces using only a small number of parameters. Which of them represent surface details the best is still an open issue. To find out which parameters can be the most suitable in that case, three groups of machined textured surfaces were prepared. They were plateau-honed cylinder surfaces made of gray cast iron, steel, and bronze surfaces with isolated dimples and steel surfaces after abrasive blasting followed by lapping. All of them were measured by means of a white light interferometer. Different parameters and relationships were evaluated and based on them correlation and regression analyses were used. The basic description contained statistically independent parameters that can be used in production control, while the wider description in scientific research. In general, parameters of random surfaces were more intercorrelated than those of surfaces with isolated dimples. As was found for the basic description of random two-process surfaces, five parameters were enough while description of textured surfaces with isolated oil pockets needed six. In wider, scientific description, regardless the surface type seven parameters contained the necessary information about the surface. It was also proved that a pair of parameters, the emptiness coefficient Sp/Sz and Sq/Sa, can describe the shape of the ordinate distribution of machined textured surfaces better than, for example, skewness Ssk and kurtosis Sku, commonly used for that purpose. Full article

(This article belongs to the Special Issue Surface Inspection and Description in Metrology and Tribology (Second Volume))

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Open AccessArticle

Experimental Study on the Manufacturing of Steel Inclined Walls by Directed Energy Deposition Based on Dimensional and 3D Surface Roughness Measurements

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Materials 2022, 15(14), 4994; https://doi.org/10.3390/ma15144994 - 18 Jul 2022

Cited by 2 | Viewed by 1061

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Robotic-directed energy deposition has attracted the attention of the research community and industry as a process capable of producing large metallic parts. The selection of the manufacturing conditions is a critical step in improving the process efficiency and quality of the produced parts. [...] Read more.

Robotic-directed energy deposition has attracted the attention of the research community and industry as a process capable of producing large metallic parts. The selection of the manufacturing conditions is a critical step in improving the process efficiency and quality of the produced parts. The present work aims at analyzing the geometry and surface topography of walls built using several conditions and inclination angles, without additional supports except for the substrate. The walls were made of AWS A5.18. ER70S-6 steel using the Wire Arc Additive Manufacturing process. The study used both dimensional and 3D topography measurements to analyze the results. As findings, the travel speed played an important role in the size of the cross-section due to the heat input to the welding zone. Heat accumulation was a critical factor in the size and accuracy of the beads. Moreover, intermediate cooling provided structures with more uniform dimensions, smaller width, and higher layer growth. The inclination of the pieces influenced the width and uniformity of the beads, generating minor imperfections on the downside of the pieces because of gravity. Full article

(This article belongs to the Special Issue Surface Inspection and Description in Metrology and Tribology (Second Volume))

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Open AccessArticle

The Effects of Selected Measurement Errors on Surface Texture Parameters

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Materials 2022, 15(14), 4758; https://doi.org/10.3390/ma15144758 - 07 Jul 2022

Cited by 2 | Viewed by 810

Abstract

Surface texture measurement, characterized by areal parameters, is very susceptible to measurement errors. Various types of errors differently affect surface texture parameters. In this paper, two types of measurement errors were investigated. To analyze the impact of the presence of scratches, circular valleys [...] Read more.

Surface texture measurement, characterized by areal parameters, is very susceptible to measurement errors. Various types of errors differently affect surface texture parameters. In this paper, two types of measurement errors were investigated. To analyze the impact of the presence of scratches, circular valleys of various diameters were added to surface textures measured by a white light interferometer. Measurement errors were larger for higher scratches. Skewness and kurtosis were mostly affected by the presence in valleys, and changes of spatial parameters were also comparatively high. The difference between the results of measurement of the same surface details two times after a break of three months was also studied. This difference was caused by errors of relocation, spikes and non-measured point presences, high-frequency noise, and surface ageing. Spatial parameters were found to be the most stable. Full article

(This article belongs to the Special Issue Surface Inspection and Description in Metrology and Tribology (Second Volume))

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