Surface Roughness Parameters Research Articles

The evaluation of the efficiency of different waxes on some physical and surface properties of fiberboard

Bilindiği üzere odun esaslı levha ürünlerinin özellikle kullanım yerlerinde suya ve rutubete maruz kaldıklarında dayanımlarının az olması bu ürünlerin dezavantajlı olarak kabul edilen ve iyileştirilmesi gereken özelliklerinden biridir. Bu nedenle odun esaslı levhaların suya, rutubete karşı dayanımlarını artırabilmek adına üretimleri esnasında su itici maddeler kullanılmaktadır. Bu çalışmada, levha üretiminde yaygın olarak kullanılan su itici maddelerden biri olan parafine alternatif olarak iki farklı vaks-mum türü seçilmiş ve etkinlikleri değerlendirilmiştir. Levha örneklerinin 2-24 saat süre için kalınlığına şişme (KŞ) ve su alma (SA) değerleri, yüzey pürüzlülük parametreleri ile yüzey sertlik değerleri belirlenmiştir. Ölçümler sonucunda, kontrol grubuna kıyasla diğer grupların KŞ ve SA oranlarında belirgin derecede iyileşme olduğu belirlenmiştir. Özellikle sadece parafin, parafin-balmumu ve parafin-soya vaksı karışımlarının tutkala ilave edildiği grupların oldukça düşük SA ve KŞ değerleri verdiği görülmüştür. Yüzey pürüzlülük parametreleri ise vaks türüne, uygulama yöntemine bağlı olarak değişim göstermiştir. En yüksek yüzey sertlik değeri balmumu ve parafinin karışım halinde yüzeye uygulandığı grupta elde edilmiştir. Buna göre, kullanılan bitkisel ve hayvansal vaks türlerinin de su itici etki gösterebilecekleri, özellikle uygun yöntem ve farklı kombinasyonlarla uygulanmaları durumunda etkinliklerinin artırılabileceği düşünülmektedir.

Investigation of color and roughness properties of heat-treated pine wood after accelerating weathering

Bu çalışmada, sarıçam (Pinus sylvestris L.) odununun oksijen (açık sistem) ve vakum altında (kapalı sistem) ısıl işlemi sonrası hızlandırılmış yaşlandırma testi performansı incelenmiştir. Örnekler 75 (Radyal) × 15 (Teğet) × 150 (Lifler) mm boyutlarında çam diri odun kısmından hazırlanmıştır. Hızlandırılmış yaşlandırma testi sonrası örneklerin yüzey pürüzlülüğü ve renk ölçümü gerçekleştirilmiştir. Sonuçlara göre minimum renk değişimi 190 °C’de kapalı sistemde (VHT) gerçekleştirilen ısıl işlem sonrası elde edilmiştir. Kapalı sistemde ısıl işlem görmüş sarıçam örneklerinin yüzey pürüzlülük parametreleri ısıl işlem sıcaklığındaki artışla birlikte artmıştır. Kapalı sistemde gerçekleştirilen ısıl işlemde, açık sistemde (HT) gerçekleştirilen ısıl işleme kıyasla daha düşük pürüzlülük değerleri elde edilmiştir. Hızlandırılmış yaşlandırma süresinin artışına paralel olarak toplam renk değişimi ve pürüzlülük değerleri artış göstermiştir.

Investigation of some technological properties of Anatolian boxwood (Buxus sempervirens L.) stem wood

şimşiri (B. sempervirens L.) gövde odununun anatomik özellikleri, rutubet miktarı, yoğunluk değerleri, liflere paralel basınç direnci, renk parametreleri ve yüzey pürüzlülük değerleri belirlenmiştir. Araştırma materyali Trabzon’un Çaykara ilçesinden alınmıştır. Gövde odunu, gerçekleştirilecek testler için kesilerek deney örnekleri elde edilmiş ve deney örnekleri hava kurusu hale gelinceye kadar iklimlendirme odasında bekletilmiştir. Testler, ilgili standartlara göre gerçekleştirilmiştir. Elde edilen sonuçlar değerlendirildiğinde Anadolu şimşiri odununun dağınık traheli olduğu, hava kurusu yoğunluk değerinin 0,94 g/cm3 ve “ağır ağaçlar” sınıfında yer aldığı, liflere paralel basınç direncinin 70,64 N/mm2 ve “basınç direnci büyük ağaçlar sınıfında” yer aldığı belirlenmiştir. Yüzey pürüzlülük parametrelerine ait sonuçlara göre şimşir odununun radyal yüzeyinin teğet yüzeyden daha pürüzlü olduğu; renk parametrelerine ait sonuçlara göre teğet yüzeyinin radyal yüzeyden daha açık renkte olduğu ve her iki yüzeyin sarı renk tonunda olduğu belirlenmiştir. Çalışmak için sert bir oduna sahip olan Anadolu şimşiri odunu süs eşyası, alet sapları, kaşık, tarak, tavla pulu, cetvel, müzik aleti parçaları üretiminde, oymacılık, tornacılık ve kakmacılıkta yaygın olarak kullanılmaktadır. Ülkemiz ormancılığında odun dışı orman ürünü olarak alternatif tıp alanında ve süs bitkisi olarak peyzaj alanında da değerlendirilen şimşir ağaçlarının korunması ve canlılığını sürdürebilmesi için gerekli çalışmaların yapılması önerilmektedir.

Study of the Machining Process of GFRP Materials by Milling Technology with Coated Tools

Glass fibers are often used as reinforcing fibers in reinforced polymers. Composites reinforced with glass fibers (GFRP) stand out with excellent mechanical and physical properties applicable to industrial practice. Machining these composites requires the correct choice of tools and cutting conditions so that the machined surface shows good properties, there is no fiber delamination, thermal stress on the workpiece and the tool, or excessive tool wear. The study was devoted to circumferential milling of fabric-bonded GFRP plates, in which attention was paid to the influence of the abrasive effect of glass fibers on wear and tool life. Attention was also paid to surface roughness after machining, material delamination, and forces during machining were measured. Three end mills of the same diameter with different coatings, number of teeth, and geometry were selected for the study. This choice of tools was intended to achieve various accompanying and subsequent phenomena that were investigated. Milling was performed on a CNC milling center under preselected cutting conditions. The paper summarizes information on fiber delamination and machined laminate damage after milling, tool wear, and surface roughness parameters as a function of tool wear. This paper provides an opportunity for researchers to increase their knowledge of specific aspects of milling GFRP composites, whether with a tool specifically designed for this or not.

A Contrast Minimization Approach to Remove Sun Glint in Landsat 8 Imagery

Sun glint, i.e., direct solar radiation reflected from a water surface, negatively affects the accuracy of ocean color retrieval schemes if entering the field-of-view of the observing instrument. Herein, a simple and robust method to quantify the sun glint contribution to top-of-atmosphere reflectances in the visible and near-infrared is proposed, exploiting concomitant observations of the sun glint’s morphology in the shortwave infrared. The method, termed Glint Removal through Contrast Minimization (GRCM), requires high spatial resolution (ca. 10–50 m) imagery to resolve the sun glint’s characteristic morphology, meeting additional criteria on radiometric resolution, signal-to-noise ratio, and temporal delay between the individual band’s acquisitions. It has been applied with good success to a selection of cloud-free Landsat 8 Operational Land Imager (OLI) scenes, otherwise encompassing a wide range of environmental conditions in terms of observation geometry, glint intensity, water types, as well as aerosol and Rayleigh optical depths. GRCM is entirely image based and does not require ancillary information on the sea surface roughness or related parameters (e.g., surface wind), nor the presence of homogeneous clear water areas in the image under consideration. GRCM’s limitations are discussed, and its potential for sensors other than OLI as well as applications beyond glint removal are sketched.

Evaluation of Surface Roughness Parameters of HDF for Finishing under Industrial Conditions.

One of the most important properties of the surface of wood-based panels is their roughness. This property determines the way of working with the material in the processes of gluing and surface varnishing. The aim of this study was to determine the effect of various sanding belt configurations and the feeding speed of the conveyor belt during grinding on the surface roughness of high-density fiberboards (HDF). The research material was prepared under industrial conditions. Three types of boards were selected for the tests. After grinding, the roughness parameters were measured both transversely and longitudinally relative to the grinding direction, using a Mitutoyo SJ-210 profilometer and the optical method. Based on ANOVA analysis of the data, it was found that the type of HDF boards used and the configuration of the abrasive belts had a statistically significant impact on the roughness. The samples for which the grinding process was performed with sanding belts of the highest grain size had the lowest roughness. For the amplitude roughness parameters, the direction of roughness measurement had a significant influence. These results may provide valuable guidance for the furniture industry in the preparation of HDF for furniture production.

Acceleration of surface roughness evaluation using RANSAC and least squares method for Running-in wear process analysis of plateau surface

ISO 21920–2 defines an analysis method and the roughness parameters needed for evaluating the roughness of plateau structure surfaces. The roughness parameters are calculated by fitting straight lines to a material ratio curve. The analysis method by ISO 21920–2 cannot calculate the roughness parameters of surfaces with insufficient plateau structure. In previous studies, analysis methods that enable the calculation of roughness parameters for surfaces with insufficient plateau structure were proposed. However, these analysis methods have the problem that the algorithms do not achieve both automation and speed-up of the plateau surface analysis. Therefore, in order to solve this problem, we propose a new method called “Straight Lines Fitting using RANSAC and Least Squares Method (RLF method)”. RLF method enables the automatic and more than 100 times faster calculation of roughness parameters for surfaces with insufficient plateau structure. RLF method is expected to contribute to improvements in productivity at production sites.

Taguchi analysis of shot peening parameters for surface hardness, wear resistance, roughness, and residual stress in Ti-6Al-4V alloy

Taguchi analysis of shot peening parameters for surface hardness, wear resistance, roughness, and residual stress in Ti-6Al-4V alloy

The Effect of Simulated Chewing on the Surface Roughness of Direct and Indirect Resin-Composites Opposed by Zirconia: An In Vitro Study.

Purpose To assess the surface roughness of two different light-cured resin-composites when opposed by monolithic zirconia after simulated mastication. Materials and Methods Materials included a direct restorative nanohybrid (n = 10) and an indirect microhybrid (n = 10) resin-composite (Tetric EvoCeram and Sinfony, respectively). The antagonist material was 3 mol% yttria-stabilized tetragonal zirconia polycrystalline ceramic. Each material was subjected to in vitro chewing against zirconia using a chewing simulator for 250,000 cycles. A 3D profilometer was used to assess the surface roughness parameters of each resin-composite before and after the simulated chewing. Independent t-test and paired sample t-test were performed to compare roughness values for both materials and to compare baseline and after chewing simulation values (p = 0.05). Results Sinfony showed significantly greater roughness values compared to Tetric EvoCeram (p ≤ 0.025) before and after simulated chewing, except for Sa and Sv parameters after simulated chewing where the difference between the two materials was insignificant (p = 0.06 and 0.89, respectively). Surface roughness increased for both materials after simulated chewing compared to baseline values, but the difference was insignificant (p ≥ 0.065). However, Sa (p = 0.04) and Sv (p = 0.012) for Tetric EvoCeram were significantly higher after compared to before chewing simulation. Conclusion Tetric EvoCeram had a smoother surface than Sinfony before and after simulated chewing. Surface roughness for both materials was higher after simulated chewing compared to baseline values which represent surface damage that was significant for Tetric EvoCeram while Sinfony showed better resistance.

Effects of Different Titanium Surface Treatments on Adhesion, Proliferation and Differentiation of Bone Cells: An In Vitro Study.

The objective of this study was to evaluate the impacts of different sandblasting procedures in acid etching of Ti6Al4V surfaces on osteoblast cell behavior, regarding various physicochemical and topographical parameters. Furthermore, differences in osteoblast cell behavior between cpTi and Ti6Al4V SA surfaces were evaluated. Sandblasting and subsequent acid etching of cpTi and Ti6Al4V discs was performed with Al2O3 grains of different sizes and with varying blasting pressures. The micro- and nano-roughness of the experimental SA surfaces were analyzed via confocal, atomic force and scanning electron microscopy. Surface free energy and friction coefficients were determined. hFOB 1.19 cells were seeded to evaluate adhesion, proliferation and osteoblastic differentiation for up to 12 d via crystal violet assays, MTT assays, ALP activity assays and Alizarin Red staining assays. Differences in blasting procedures had significant impacts on surface macro- and micro-topography. The crystal violet assay revealed a significant inverse relationship between blasting grain size and hFOB cell growth after 7 days. This trend was also visible in the Alizarin Red assays staining after 12 d: there was significantly higher biomineralization visible in the group that was sandblasted with smaller grains (F180) when compared to standard-grain-size groups (F70). SA samples treated with reduced blasting pressure exhibited lower hFOB adhesion and growth capabilities at initial (2 h) and later time points for up to 7 days, when compared to the standard SA surface, even though micro-roughness and other relevant surface parameters were similar. Overall, etched-only surfaces consistently exhibited equivalent or higher adhesion, proliferation and differentiation capabilities when compared to all other sandblasted and etched surfaces. No differences were found between cpTi and Ti6Al4V SA surfaces. Subtle modifications in the blasting protocol for Ti6Al4V SA surfaces significantly affect the proliferative and differentiation behavior of human osteoblasts. Surface roughness parameters are not sufficient to predict osteoblast behavior on etched Ti6Al4V surfaces.

Analysis of geometric structure of woven fabrics surface.

The geometric structure of the surface of textile materials is of significant functional, operational and aesthetic importance. The basic parameters of the woven fabrics’ structure are the following: weave, warp and weft density as well as warp and weft linear density. Roughness is one of the surface quality features most often assessed by quantitative indicators called surface roughness parameters. The aim of the presented research was to analyze the parameters characterizing the geometric structure of the surface of cotton woven fabrics with different weaves. Surface topography measurements were performed using the MicroSpy® Profile profilometer by FRT the art of metrology™. Using the Mark III software cooperating with the profilometer, a number of indices characterizing the geometric structure of the fabric surface and histograms illustrating the frequency of occurrence of points of a certain height on the tested surface were determined. The research confirmed that, on the basis of the results obtained with the profilometer, it is possible to analyze comprehensively the topography of the fabric surface.

Novel method for numerical reconstruction of grinding surfaces with specified roughness parameter set

Surface roughness parameters play a decisive role on grinding surface service performance. Among 26 surface roughness parameters, closely related to the surface performance and defined by ISO25178, in the 6 categories, numerical reconstruction of grinding surfaces can only control 7 height parameters and 2 spatial parameters with inability to achieve precise control of other parameter-defined features. Therefore, a novel numerical reconstruction method for grinding surfaces with specified rough parameter set (SRPS) was proposed to solve the problem of feature loss caused by other uncontrollable parameters. Combine three characteristic coefficients of height probability density function in Johnson transformation method with four characteristic coefficients of autocorrelation function expression to construct surface reconstruction coefficient set (SRCS) and build SRPS with number of 22 in consideration of the measurement error influence and industrial application frequency. Use BP neural network to establish quantitative mapping model between SRCS and SRPS for inversion. Through introducing genetic algorithm to invert SRPS corresponding SRCS, numerical reconstruction of grinding surfaces with SRPS will be realized. Experimental results show that compared with the measured grinding surfaces, the average error in SRPS of reconstructed surfaces is basically within 10%. The research provides a new means for the study of the surface performance, which solves the problem that the traditional rough surface modeling method based on random process theory could only associate 9 roughness parameters.

On the optimal texture shape with the consideration of surface roughness

The optimal texture shape considering surface roughness is determined by solving the average Reynolds equation, selecting Jakobsson–Floberg–Olsson boundary conditions, and using a genetic algorithm. The effects of surface roughness as indicated by the combined root-mean-square (RMS), surface pattern parameter, and operating parameters on the friction coefficient, area ratio, and depth of the optimal self-defined shape and optimal dimple were studied. Results show that the friction coefficient will be significantly reduced during the shape optimization considering the effect of surface roughness. The variation laws of the optimal dimple area ratio with the combined RMS, surface pattern parameter, minimum film thickness, sliding speed and the variation law of the optimal depth of the optimal self-defined shape with surface roughness and working parameters are obtained. Finally, this study concludes that the influence of roughness parameters on the optimal dimple shape is greater than that on the optimal self-defined shape under different sliding speeds.

Effect of Surface Microparameters on Contact Temperature of Sliding Electrical Contact

Sliding friction pair composed of contact wire and pantograph slide is the key component of train current collection system. Contact temperature is one of the important factors affecting the current-carrying and wear performance of the friction pair. In this article, sliding electrical contact experiments under different experimental conditions were conducted. Based on the measured contour curve of the slide surface, two fractal parameters of the slide surface were calculated by using the structure function method. And the effect of contact current, contact pressure, and sliding speed on the fractal parameters was discussed. A temperature field simulation model of sliding electrical contact considering two rough contact surfaces was established with COMSOL Multiphysics software. The effect of surface roughness and fractal parameters on contact temperature was analyzed by simulation. When other simulation parameters keep constant, the contact temperature first drops and then rises as the average roughness height of the contact surface increases. The average roughness slope of the contact surface has little effect on the contact temperature under high speed and strong current conditions. The contact temperature continuously decreases with the increase of fractal dimension or the decrease of fractal roughness. The conclusions can be used as a basis for further research on the contact temperature characteristics of the friction pair to improve its electrical contact performance.

The effect of protective and decorative coatings on the strength of adhesive joints of hot-dip galvanized steel sheets

The influence of chromate, phosphate, glossy and brightening coatings on the performance of adhesive joints of hot-dip zinc-coated steel sheets was compared. The contribution of this study has been to compare the adhesive joint strength in adherends with two types of coatings: steel sheet with zinc coating and additional coating. Two types of bisphenol A (BPA) epoxy adhesives were used to assemble the joints, that were subject to shear stresses. The surface of the adherends was described in terms of surface roughness parameters. The highest value of the shear strength was recorded for the adhesive joints of the hot-dip zinc-coated steel sheets with chromate passivation and brightening. The poorest performing joints were of the glossy galvanized steel sheets.

Tribological properties of Al2O3 layers after thermo-chemical treatment

The article presents the influence of the thermo-chemical treatment of Al2O3 layers on their tribological properties. The Al2O3 layers were produced on the EN AW-5251 aluminium alloy by means of direct current anodizing in a three-component electrolyte. For the sake of comparison, some of the samples were thermochemically treated in three liquids (sodium sulphate solution, sodium dichromate solution, distilled water). The parameters of the production and thermo-chemical treatment were selected on the basis of two Hartley's plans. The tribological properties were determined on the basis of a tribological test carried out for a pin-on-disc friction pair on a T-17 tester in reciprocating motion. The tests were carried out in conditions of technically dry friction. Thanks to the tests, coefficient of friction µ and the mass wear, together with the intensity of the material wear were determined. The use of thermo-chemical treatment in the sodium dichromate solution contributed to an increase in coefficient of friction μ and a reduction in the wear intensity of the polymer from 36 μg/km (layer without thermo-chemical treatment) to 21.33 μg/km (layer after thermo-chemical treatment in the sodium dichromate solution).The conducted stereometric tests before and after the tribological test for selected samples allow the authors to state that the thermo-chemical treatment in the sodium dichromate solution increases the amplitude parameters of surface roughness. The study of the surface morphology of the layer with the lowest mass wear showed the formation of an additional sub-layer as a result of thermo-chemical treatment carried out in the sodium dichromate solution.

Surface Characterization of Lüders Band on NiTi Shape Memory Alloy

The tensile deformation of NiTi alloy can proceeds in either homogeneous manner, or localized deformation via formation and propagation of macroscopic shear bands, that is commonly known as Lüders-like deformation. The high deformation strain within the localized deformed regions can result in the changes of surface characteristics of NiTi specimen. This paper studies the surface roughening effect associated with Lüders-like deformation of martensitic NiTi alloy, via surface characterization of polished surface and localized deformed region that consists of Lüders bands on tensile specimens, respectively. The surface roughness profile and roughness parameters of surface with Lüders bands are significantly different and higher as compared to the polished surface.

Revisiting the Surface Energy Parameters of Standard Test Liquids with a Corrected Contact Angle Method over Rough Surfaces.

Interfacial free energy is a quantitative basis for explaining and predicting interfacial behavior that is ubiquitous in nature. The contact angle (CA) method can determine the surface free energy (γ) as well as Lifshitz-van der Waals (γLW) and Lewis acid/base (γ+/γ-) components of a solid material from its CAs with a set of known test liquids according to the extended Young-Dupré equation. However, the reliability of the "known" parameters of the test liquids is questioned due to the long-neglected surface roughness effect during calibration of the liquids. This study proposed a simple and practicable two-step approach to correct the energy parameters of several test liquids by incorporating Wenzel's surface roughness relationship into CA measurement. Step 1: water and two apolar liquids (diiodomethane and α-bromonaphthalene) were used as benchmarks to calibrate the surface roughness and energy parameters of two reference solids [apolar poly(tetrafluoroethylene) and monopolar poly(methyl methacrylate)], and step 2: the reference solids were used to calibrate any other test liquids by solving the energy parameters from their CAs in the extended Young-Dupré-Wenzel model. Monte Carlo simulation was used to evaluate error transmission and robustness of the model solutions. The obtained energy parameters (γLW/γ+/γ-) of four test liquids (dimethyl sulfoxide, formamide, ethylene glycol, and glycerol) are 28.01/13.68/4.67, 34.95/3.53/37.62, 26.26/7.51/15.74, and 32.99/9.24/26.02 mJ/m2, respectively, and different from the literature values. The liquids were applied to characterize an example solid surface with true γLW/γ+/γ- values of 28.00/1.00/8.00 mJ/m2 and a roughness index (r) of 1.60. Without correction of the liquid parameters, the calculated surface energy, hydration energy, and hydrophobic attraction energy of the solid sample can deviate by 50, 13, and 27%, respectively. This proves the necessity of correcting parameters of the test liquids before they can be used in CA and interfacial energy studies in the presence of surface roughness.

A Fully Coupled Normal and Tangential Contact Model to Investigate the Effect of Surface Roughness on the Partial Slip of Dissimilar Elastic Materials

By adopting a global search method for all shear tractions in the contacting area and using an alternative convergence criterion regarding load balance in the lateral direction, the newly developed algorithm provides stable solutions to partial-slip problems of elastically dissimilar materials. The model is validated via the comparison between the simulation and literature results for a sphere-on-flat problem under fully coupled conditions. It is then employed to investigate the influence of surface roughness parameters including the root mean square (RMS) roughness and RMS slope on partial-slip solutions under coupled conditions. Since the gross sliding condition is modified under coupling effects, the relationship between the ratio of the stick area to the contacting area (stick ratio) and tangential load in the coupled case, unlike that in the uncoupled one, becomes non-linear for all tested rough surfaces. Under low or medium tangential loads, the surface with a higher RMS gradient or a lower RMS roughness experiences more stick regions within the contacting area. This trend then becomes irregular at higher tangential loads.

Effect of cryogenic cutting surface integrity on fatigue life of titanium alloy Ti-5553

Titanium alloy Ti-5553 has the advantages of high strength and corrosion resistance, but its high cutting temperature and chemical activity in the machining process reduce its surface integrity. In this paper, the effect of surface integrity on fatigue life is analyzed in terms of surface morphology, microstructure, and residual stresses through liquid nitrogen cryogenic and dry cutting Ti-5553 experiments. The results show that the surface roughness parameter Ra and Sq both show a trend of decreasing and then increasing under the same cutting parameters. Under cryogenic cutting effectively improves surface integrity and extends the fatigue life of the specimen.