Roughness Measurements Research Articles

The Influence of Roughness of Surfaces on Wear Mechanisms in Metal–Rock Interactions

The processes of rock excavation and processing involve intense mechanical stresses on cutting, displacing, and transporting tools, inevitably leading to the phenomenon of dry friction wear. The factors influencing the intensity and mechanisms of wear are complex and interdependent, being conditioned by the physical–mechanical properties of the rocks, the geometric characteristics and materials of the tools, as well as the cutting process parameters (cutting force, feed rate). Previous studies have mainly addressed the global aspect of wear without delving into the microstructural evolution of the contact surfaces during the friction process. In this paper, through controlled tribometric tests, we have investigated in detail the abrasive wear mechanisms of metallic materials in contact with different types of rocks, with an emphasis on the role played by surface roughness and the mineralogical properties of the rocks. Experimentally, we varied the applied forces and the number of friction cycles to simulate different working conditions and evaluate how these parameters influence wear intensity and surface morphology evolution. Microstructural analysis of the samples, combined with roughness measurements, allowed the identification of the predominant degradation mechanisms (abrasion, adhesion, fatigue) and their correlation with the material properties and the friction process parameters. The results have shown a strong correlation between the wear capacity of rocks and their petrographic properties, such as hardness, porosity, and hard mineral content. It was also found that the roughness of the contact surfaces plays an essential role in wear mechanisms, influencing both the initiation and propagation of its effects. Depending on the experimental data, we have developed a classification of rocks based on their abrasive potential and proposed criteria for the optimal adoption of materials and working parameters for the tools of technological equipment depending on the type of rock encountered. The results of this study can contribute to improving the durability of tools, as well as mining equipment, and reducing operating costs.

Surface quality of planed tangential and radial sections of thermally modified Silver fir wood

The quality of glued or coated wood largely depends on the strength of the bond between the adhesive or coating and the wood surface. The roughness of the surface plays a crucial role, as it significantly impacts both the wettability and the effectiveness of the bond. This study was carried out to provide information on the surface roughness of Abies alba (silver fir) planed after thermal modification, focusing on the anisotropic behavior of the material, particularly along the radial and tangential sections. Four groups of eight samples without defects were prepared. Half of the samples of each group presented clear tangential section while the other half presented clear radial ones. One group was used as control and the others were heated, applying three different temperatures 160 °C, 190 °C and 220 °C, at atmospheric pressure for 3 hours. The control and the three other heat-treated groups of samples were processed along the grain by a planer machine. 10 m/min feed speed was applied. Surface roughness measurements were performed with a stylus profilometer. A positive correlation was observed between the modification temperature and the roughness of the surface. It was noted that the radial section of natural wood presented greater roughness than the tangential one. For temperatures lower than 200 °C the roughness of both sections resulted almost equal, while above this temperature the roughness of the radial section increased over 20 % compared to the roughness of the tangential one. The information provided by this study is very important for the gluing and finishing processes that can be applied to thermally modified wood.

Effect of modeling liquid application on color stability and surface roughness of single-shade composites

ObjectivesThe objective of this study was to examine the effects of modeling liquid application on the color stability and surface roughness of single-shade composites.Materials and methodsSingle-shade composites were divided into 4 main groups according to their contents. A total of 64 disc-shaped samples (8 × 2 mm) were prepared, 16 in each group, by using Teflon molds. The samples were divided into two subgroups on the basis of the application of a modeling liquid. After the initial color and roughness measurements, the samples were immersed in coffee for 12 days. Color changes were assessed via a spectrophotometer and ΔE values were calculated via the CIELAB formula. The surface roughness (Ra) was measured via a profilometer. The data were subjected to statistical analysis via two-way analysis of variance and Tukey’s test to examine pairwise differences at a significance level of 0.05.ResultsThe application of modeling liquid reduced discoloration in Charisma Diamond One (CDO) and Vittra APS Unique (VUA), whereas it slightly increased discoloration in Omnichroma (OMN) and Zenchroma (ZNC). However, only the changes in CDO were statistically significant (p < 0.05). Among the composite control groups baseline and after the coloring procedures, the highest surface roughness degree was observed in the CDO group, while the lowest surface roughness degree was observed in the OMN and ZNC groups (p < 0.05), and the differences between them were found to be significant (p > 0.05). The surface roughness and color changes approached the mean values in the subgroups where the modeling liquid was applied, and there was no significant difference between them (p > 0.05). The application of modeling liquid was observed to reduce the variation in initial roughness among the composites, bringing their roughness values closer to an average range (0.26–0.34).ConclusionModeling liquid application increased roughness and discoloration in composites with initially low surface roughness (OMN and ZNC) while reducing roughness and discoloration in composites with initially high surface roughness (VUA and CDO).Clinical relevanceModeling liquid application should be approached more cautiously in composites with high polishability, despite contributing to clinical use in composites with high roughness values.

Long Term Performance of Sustainable Concrete Pavement Preservation Strategies in Canada

Rigid pavement preservation and rehabilitation strategies for high traffic volume roads are important sustainable methods of extending the life of our concrete roadways. In 1989, the Ministry of Transportation of Ontario (MTO) undertook the rehabilitation of an exposed concrete pavement exhibiting various distresses. The existing pavement, originally constructed in 1963, consisted of 230 mm mesh reinforced Portland Cement Concrete (PCC) pavement with dowelled joints at a spacing of 21.3 m. The preservation strategies used on the northbound lanes, which had experienced moderate deterioration, consisted of using sustainable concrete pavement restoration (CPR) techniques, material specifications and construction methods, which included full depth repair, partial depth repair, diamond grinding and joint sealant replacement. The rehabilitation strategy selected for southbound lanes was a 180 mm thick plain jointed unbonded PCC overlay to address the severe 'D' cracking and spalling at all the joints and cracks. This paper will identify the sustainable concrete pavement preservation strategies using the pavement sustainability rating system – GreenPave. It will also discuss the pavement preservation strategies and their long term performance evaluation in terms of roughness measurements, frictional resistance measured, and pavement condition ratings. Overall, the 22 year performance of these preserved and rehabilitated concrete pavements has been good with acceptable levels of ride quality, frictional resistance and distress propagation.

Effect of Different Beverages and Polishing Systems on Color Stability and Surface Roughness of a Smart Chromatic Composite Resin and Methacrylate Composites

Objective: The purpose of the study is to evaluate the color stability and surface roughness of smart chromatic composite resin and methacrylate composite resins with applying different polishing systems and stored in different solutions. Methods: In the study, 120 disc-shaped specimens were prepared from a smart chromatic composite, a nanofill composite, and a nanohybrid composite. The specimens were separated into 12 groups with a specimen size of 10, and the two different polishing systems were utilized. The initial color values of the specimens were measured with a spectrophotometer and the surface roughness values were measured with a profilometer. Then, the specimens were stored in two different beverage solutions, and color and roughness measurements were repeated. The mean color change values of the specimens were calculated in ΔE, and the surface roughness values were recorded in Ra. Statistical analysis of the data was performed using One-way ANOVA and post hoc Tukey test (P =.05). Results: Statistically significant variations were observed in the mean color change values among the groups, as a consequence of the utilization of various polishing systems and exposure to different solutions (P.05), significant distinctions were identified among the groups to which different polishing systems were employed (P

Quantitative in-vitro evaluation of enamel surface roughness following two debonding procedures using laser scanning confocal microscope.

The objective of the in vitro study was to evaluate the impact of two adhesive removal techniques on the surface roughness of the human enamel surface using laser scanning confocal microscopy (LSCM). Forty healthy first upper molar teeth were included in this experiment (20 teeth per each group). T0 measurement of surface roughness parameter of the teeth were conducted using LSCM. The teeth were bonded with metal brackets. Following 24 hours of sample storage in distilled water, the brackets were debonded. A modified adhesive remnant index (ARI) was used to exclude samples with below 90% adhesive remnants on their surface. The remaining 36 teeth were then randomly divided into two groups (18 teeth per group) with the following debonding procedures: group TC (single stage method using a Smoozie tungsten carbide bur) and group TCP (two stage method using a Smoozie tungsten carbide bur, followed by a Smoozie polisher). The time needed for complete adhesive removal was recorded and T1 surface roughness measurements were conducted again after adhesive removal using LSCM. Significantly higher surface roughness values were recorded in group TC, compared to group TCP (P<0.01). Method TCP, on the other hand, was significantly more time-consuming than method TC (P<0.01). Despite the fact that the two-stage method (group TCP) was more time consuming, the lower level of enamel surface roughness in this method suggests the superiority of this method.

Québec’s Experience with Smoothness Specifications on Concrete Pavements

Smoothness is one of the most important characteristics of pavement because it directly affects the traveling public. Furthermore, the initial smoothness reflects the quality of construction and is an essential condition for the pavement’s future performance. The Québec Ministry of Transportation (MTQ) has been using smoothness specifications for all concrete pavement projects since the early 1990s. The Profile Ride Index (PRI) was replaced in 1998 by the International Roughness Index (IRI) so the same specifications would apply for concrete and asphalt pavements. IRI specifications stated that profile measurements be made with a truck-mounted inertial profiler after the work is finished. Today, some contractors are still using the profilograph for control purposes during construction and there has been an increase in diamond grinded surface area, up to 32% on some projects. A study was undertaken in 2000 to assess different kinds of roughness measuring equipment (profilograph, Disptick©, lightweight inertial profiler, rolling profiler and 2 types of truck-mounted inertial profiler) and determine those that would be best suited for construction control. This study concluded that the rolling profiler was the best equipment for this purpose. In 2003, MTQ experimented with modified specifications requiring that roughness measurements be made using a rolling profiler and forbidding any surface correction before the measurements were made. The main benefits of this method were that MTQ could check the 100-metre control lots soon after they were built instead of waiting until the end of the work and the contractors could also use the results for own quality control.

Fifteen Years Performance of a Concrete Pavement Rehabilitation Project in Canada

The Ministry of Transportation of Ontario (MTO) undertook the rehabilitation of an exposed concrete pavement exhibiting various distress manifestations in the summer of 1989. Highway 126 in Southwestern Ontario is a four-lane divided arterial with 22,000 AADT and 9.6% commercial traffic in year 2000. The existing pavement, originally constructed in 1963, consisted of 230 mm mesh reinforced Portland Cement Concrete (PCC) pavement with dowelled joints at a spacing of 21.3 m. The rehabilitation strategy selected for southbound lanes was a 180 mm thick plain jointed unbonded PCC overlay to address the severe 'D' cracking and spalling at all the joints and cracks. The rehabilitation of the northbound lanes, which had experienced moderate deterioration, consisted of using the latest concrete pavement rehabilitation (CPR) techniques, material specifications and construction methods, which included full depth repair, partial depth repair, diamond grinding and joint sealant replacement. This paper will discuss the evaluation of this rehabilitated pavement in terms of roughness measurements, frictional resistance measured, and pavement condition ratings. Overall, the fifteen-year performance of the rehabilitated concrete pavements has been good with acceptable levels of ride quality, frictional resistance and distress propagation.

Sidewall Roughness Measurement and Bearing Performance Simulation of Rock-Socketed Piles Based on Laser Scanning Point Cloud

Sidewall Roughness Measurement and Bearing Performance Simulation of Rock-Socketed Piles Based on Laser Scanning Point Cloud

Effect of Coolant Concentration Ratio on Surface Roughness in Machining Aluminium 6061: A Case Study

Machining of Aluminium 6061 alloy is critical in various industries, but achieving optimal surface finish while maintaining cost-effectiveness remains a challenge. The concentration of coolants significantly impacts machining characteristics, yet its optimal ratio for specific alloys and processes is not fully understood. This study addresses this gap by investigating the effect of coolant concentration on surface roughness during the machiningof Aluminium 6061 alloy. Two coolants, Coolant A and Coolant B, were evaluated at concentrations of 5%, 7%, 9%, 10% and 11%. The researchemployed a Hision VMC 850 CNC machine with carefully controlled parameters, including a spindle speed of 1500 RPM and specific feed rates. Surface roughness measurements were taken using a Mitutoyo SJ-410 Electronic Surface Roughness tester before and after machining operations.Results demonstrated a clear correlation between increased coolant concentration and improved surface finish for both coolants.

Effect of Fused Filament Fabrication Parameters on Selected Indicators for Assessing Technological Quality of Shaped Models

Despite many studies, implementation of the additive manufacturing process in industrial and research practice is limited due to the numerous distortions affecting the obtained dependencies to a degree that is difficult to predict. No uniform methodology has been developed for the study of the impact of changes in the FFF parameters on the technological quality indicators. This paper presents a description of the original procedure for assessing technological quality using a reference component. The aim of the research was to analyze the impact of changes in the FFF additive manufacturing parameters on selected indicators of technological quality assessment of products. To compare the technological quality of the various models produced, measurements of surface roughness as well as dimensional and shape accuracy were carried out using stylus profilometry and coordinate measurement. The conducted tests showed that samples with a layer height of 0.12 mm have the most advantageous surface roughness parameters compared to the other layer heights of 0.16 mm and 0.20 mm tested. All the samples obtained were characterized by smaller dimensions than nominal, indicating the material shrinkage occurring during the FFF process. The study showed a negligible effect of material fill rate on surface roughness parameters as well as on the dimensions and shape accuracy. The obtained measurement results allow determining the most advantageous parameters of the FFF process depending on the adopted quality requirements.

Comparative Evaluation of Surface Roughness and Color Stability of Polyetheretherketone with Conventional Interim Prosthetic Materials: An In Vitro Study.

The aim of this in vitro study was to compare the surface roughness and color stability of polyetheretherketone (PEEK) with those of conventional interim prosthetic materials like polymethylmethacrylate, bis-acrylic composite, and rubberized diurethane dimethacrylate, following immersion in solutions of varying pH value. A total of 320 circular discs with 10 mm diameter and 2 mm height were divided based on the fabrication (n = 80)-group A: polymethylmethacrylate; group B: bis-acrylic composite; group R: rubberized diurethane; and group P: hot-pressed PEEK-and were subjected to baseline measurement of roughness (n = 40) and color (n = 40) using 3D profilometer and UV-Vis spectrophotometer, respectively. Later, 10 samples from each group were immersed in distilled water, black coffee, green tea, and Pepsi, respectively, for 120 days, and measurements of roughness and color were repeated. The differences in roughness (ΔRa) and color change(ΔE) were calculated and statistically analyzed with a significance level of p-value < 0.05. Irrespective of the immersion solution, the highest mean difference in the roughness values was shown by rubberized diurethane specimens: ΔRa = 3.574880 (0.0048350) in carbonated beverages, and lowest difference was shown by bis-acrylic composite: ΔRa = 0.29004 (0.0017473) in distilled water. The greatest color stability was exhibited by PEEK. The type of interim material and immersion solution had a statistically significant effect on change in color and roughness values. The immersion in solutions of varying pH had a significant effect on surface roughness and color stability of all the tested materials. The Ra value of all specimens after immersion was still within the clinically acceptable range. Polyetheretherketone was the most color stable material in all solutions, except in green tea. This study will provide guidance to dentists and patients regarding the selection of interim material for long-term use, depending on the effect of beverage consumption on its color stability and roughness. How to cite this article: Saraswathy A, Latha N, Ayyadanveettil P, et al. Comparative Evaluation of Surface Roughness and Color Stability of Polyetheretherketone with Conventional Interim Prosthetic Materials: An In Vitro Study. J Contemp Dent Pract 2024;25(10):930-935.

Effect of Dynamic Corrosion and Degradation on Fatigue Life of an AA2024-T3 Aircraft Profile: Experimental, Statistical, and Numerical Analyses

The effect of parameters such as angle of attack, flow velocity, and electrolyte concentration (saline solution) on the extent of material degradation, as well as the morphology and depth of corrosion pits in an airfoil made of 2024-T3 aluminum alloy, was studied in detail. An orthogonal L9 design of experiments (Taguchi method) was applied to promote high pitting corrosion through the quality characteristic “the higher the better”. Potentiodynamic curves of the three experiments with low, medium, and high saline concentration were obtained through the CorrTest CS350 equipment. The above allowed the determination of the electrochemical corrosion parameters under static test conditions. The corroded airfoils were analyzed using light optical microscopy (LOM). In addition, the roughness measurements correlated with the extent of the degraded surface. A complete pit shape and depth characterization was obtained by applying mechanical ground, surface wear level monitoring (every 0.01 mm), and LOM observations. Pitting defects (depth and morphology) and mechanical strength reduction were considered by a finite element (FE) model to simulate the airfoil fatigue behavior. Numerical results helped to determine the contribution of pitting and the extent of degradation on sudden airfoil failure.

Trial of Reliable Surface Roughness Measurement with Atomic Force Microscope

Trial of Reliable Surface Roughness Measurement with Atomic Force Microscope

Combining UAS LiDAR, Sonar, and Radar Altimetry for River Hydraulic Characterization

Accurate river hydraulic characterization is fundamental to assess flood risk, parametrize flood forecasting models, and develop river maintenance workflows. River hydraulic roughness and riverbed/floodplain geometry are the main factors controlling inundation extent and water levels. However, gauging stations providing hydrometric observations are declining worldwide, and they provide point measurements only. To describe hydraulic processes, spatially distributed data are required. In situ surveys are costly and time-consuming, and they are sometimes limited by local accessibility conditions. Satellite earth observation (EO) techniques can be used to measure spatially distributed hydrometric variables, reducing the time and cost of traditional surveys. Satellite EO provides high temporal and spatial frequency, but it can only measure large rivers (wider than ca. 50 m) and only provides water surface elevation (WSE), water surface slope (WSS), and surface water width data. UAS hydrometry can provide WSE, WSS, water surface velocity and riverbed geometry at a high spatial resolution, making it suitable for rivers of all sizes. The use of UAS hydrometry can enhance river management, with cost-effective surveys offering large coverage and high-resolution data, which are fundamental in flood risk assessment, especially in areas that difficult to access. In this study, we proposed a combination of UAS hydrometry techniques to fully characterize the hydraulic parameters of a river. The land elevation adjacent to the river channel was measured with LiDAR, the riverbed elevation was measured with a sonar payload, and the WSE was measured with a UAS radar altimetry payload. The survey provided 57 river cross-sections with riverbed elevation, and 8 km of WSE and land elevation and took around 2 days of survey work in the field. Simulated WSE values were compared to radar altimetry observations to fit hydraulic roughness, which cannot be directly observed. The riverbed elevation cross-sections have an average error of 32 cm relative to RTK GNSS ground-truth measurements. This error was a consequence of the dense vegetation on land that prevents the LiDAR signal from reaching the ground and underwater vegetation, which has an impact on the quality of the sonar measurements and could be mitigated by performing surveys during winter, when submerged vegetation is less prevalent. Despite the error of the riverbed elevation cross-sections, the hydraulic model gave good estimates of the WSE, with an RMSE below 3 cm. The estimated roughness is also in good agreement with the values measured at a gauging station, with a Gauckler–Manning–Strickler coefficient of M = 16–17 m1/3/s. Hydraulic modeling results demonstrate that both bathymetry and roughness measurements are necessary to obtain a unique and robust hydraulic characterization of the river.

An Initial Study of Ultra High Performance Concrete as Reusable Mold Material for Aluminum Casting.

The initial investigation evaluates the feasibility of ultra high performance concrete (UHPC) as a material for reusable molds in aluminum casting. Two specific UHPC formulations were investigated: one based on ordinary Portland cement (OPC) and another utilizing alkali-activated materials (AAM). The study focused on investigating the surface through roughness measurements and the thermal durability through repeated casting cycles. The thermal stability of the molds was investigated by thermogravimetric analysis, mercury intrusion porosimetry, crack segmentation, optical microscopy, and electron microscopy. Results indicate that molds fabricated from AAM-UHPC exhibit relatively better performance in terms of maintaining structural integrity and surface quality over repeated uses. AAM-UHPC molds were able to withstand up to ten casting cycles with acceptable surface degradation and no significant failure, while OPC-UHPC molds exhibited a faster degradation under similar conditions. Microstructural changes and the interaction of UHPC materials with molten aluminum were investigated, highlighting the low adhesion and defect formation. Additionally, the molds demonstrated sound casting quality, with a grain size comparable to that achieved using traditional steel molds (~ 90 µm), underscoring the potential of UHPC materials for enhancing casting quality and efficiency. The study concludes that UHPC, particularly with alkali-activated formulations, shows promise for low-pressure casting environments.

Tailoring of carboxymethyl guar gum hydrogels via gamma irradiation for remarkable removal of cationic and anionic dyes from simulated solutions.

Green hydrogels were synthesized from carboxymethyl guar gum (CMGG)-polyacrylic acid (PAAc) via gamma irradiation at doses of 10-40kGy, they were codes as (CMGG/PAAc). FTIR spectroscopy was applied to confirm the chemical transformation of GG into the hydrogel formulations while the 1HNMR was employed to confirm the successful preparation of CMGG. TGA, XRD, and AFM were used to compare the improved formulation to native and CMGG. The investigated hydrogels were then applied comparatively to remove methylene blue (MB) and methyl orange (MO) dyes from aqueous solution under various operating parameters. In addition, the AFM was used comprehensively to address the adsorption process by comparing the surface topographies, height and roughness measurements between the dry and dye-loaded hydrogel. Four adsorption isotherms were investigated in order to go deep through the adsorption mechanism. These are Langmuir Freundlich, Redlich-Peterson and Jovanovich isotherms. Based on the values of R2 for all the models, it can be assumed that the Langmuir model is best appropriate for the adsorption process and that the dyes were adsorbed onto a homogenous surface. Kinetic tests showed that the pseudo-second-order model best fitted the adsorption process, with R2 values of 0.9999 for both dyes, confirming chemisorption as the rate-limiting step. The thermodynamic data indicates spontaneous, exothermic adsorption processes, with Gibbs free energy changes (∆G) for MB ranging from -11.265 to -10.82kJ/mol and MO from -3.221 to -3.323kJ/mol. Negative enthalpy changes (∆H) of -17.892kJ/mol for MB and-17.005 for MO show the exothermic nature of adsorption. The data proved effective removal of MB and MO dyes onto CMGG/PAAc hydrogels with better affinity for MB dye, making them excellent wastewater treatment adsorbents.

Measurement of wettability and surface roughness for metrology and quality control in microfluidics

Measurement of wettability and surface roughness for metrology and quality control in microfluidics

Silicon-via (Si-via) hole metrology and inspection by grayfield edge diffractometry

This paper introduces a novel silicon-via (Si-via) hole metrology and inspection method based on grayfield edge diffractometry, enabling simultaneous measurement of Si-via hole geometry and roughness. The edge diffraction interferogram occurs when incident light interacts with the via edge. A grayfield imaging system consists of a pair of axicon lenses, two objective lenses and imaging system was developed to capture the fringes. Here, a pair of axicon lenses shape the collimated beam into a donut-shaped beam profile. The shaped beam has an adjustable focus point, allowing scanning along the Si-via hole depth axis. The cross-correlation approach to comprehensive analysis of the fringes was performed to extract via roundness and via-edge roughness (VER). The relationship between cross-correlation output and VER was characterized, assuming the line-edge roughness (LER) represents VER. The proposed method was cross-verified with the conventional microscopy approach. In addition, the through-focus scanning optical microscopy method was also used to intuitively characterize the fringe feature in three-dimension. In conclusion, the proposed method can characterize Si-via hole's roundness and estimate VER, showcasing potential adaptability for automated Si-via hole inspections in wafer-level hybrid bonding applications.

Surface roughness of composite resins subjected to brushing with whitening toothpastes: an in vitro study.

The emergence of toothpastes containing different abrasive and whitening substances has been a constant concern among dental professionals. The aim of the present study was to perform an in vitro assessment of the surface topography of nanoparticle composite resins subjected to simulated brushing with dentifrices. Test samples were prepared with Filtek Universal (3M ESPE), Filtek Bulkfill (3M ESPE) and Z350 (3M ESPE), with 24 samples per resin. A testing machine was used to simulate brushing with the dentifrices Colgate Total 12, Oral B 100% and Oral B Gengiva Detox Gentle Whitening (8 samples per group). The constant speed of the machine was 250 cycles per minute, and 20.000 cycles were carried out, which corresponds to 24 months (1 hour and 20 minutes). Roughness features and qualitative surface topography were investigated. Statistical analysis involved the Kruskal-Wallis, Wilcoxon and Mann-Whitney tests. A significant increase in surface roughness was found for all the resins (p < 0.05). However, no significant difference was found among the resins in terms of final roughness values (p = 0.690). In contrast, a significant difference among dentifrices was found with respect to roughness measurements (p < 0.001). The qualitative analysis revealed an increase in surface roughness in all the samples and differences in the abrasive potential of the dentifrices. In conclusion, brushing with dentifrices increases the surface roughness parameters of composite resin restorations. Moreover, the differences in the abrasive effects of the dentifrices indicate a need for further studies to establish efficacy and safety criteria.