Surface Roughness Measurements Research Articles

Effect of laser irradiation during in-office tooth bleaching on surface properties of resin-based restorative materials.

This study evaluated the changes in surface properties of three resin-based restorative materials after two laser-assisted, in-office tooth bleaching protocols using erbium, chromium: yttrium-scandium-gallium-garnet (Er,Cr:YSGG) or diode (980nm) lasers. A nanohybrid composite (Enamel Plus HRi), a Bis-GMA-free composite (Enamel Plus HRi Bio Function), and a resin-matrix CAD-CAM ceramic (Shofu Block HC) were tested. Forty specimens for each material were prepared and divided into four groups (n=10/group). The control specimens did not undergo any bleaching treatment, whereas group 2 received bleaching with 40% hydrogen peroxide (H2O2), while groups 3 and 4 underwent the same bleaching procedure with the use of diode (980nm) or Er,Cr:YSGG lasers, respectively. Surface microhardness and roughness measurements were conducted using a Vickers tester and an optical profilometer. Microhardness was lower in bleached specimens, with the nanohybrid composite exhibiting the largest difference from the no bleaching group. For the Bis-GMA-free composite the microhardness difference between no bleaching and laser-assisted bleaching were smaller than seen for the conventional bleaching technique. Surface roughness was higher in bleached specimens, with nanohybrid composite showing the largest differences from the control specimens. The examined laser-assisted tooth bleaching protocols were found not to impact surface microhardness and roughness of the tested resin-based specimens and they are deemed suitable for clinical use.

Surface Roughness Measurement of Hybrid Ceramic Materials after Immersion in Mouth Rinse and Repolishing

Surface Roughness Measurement of Hybrid Ceramic Materials after Immersion in Mouth Rinse and Repolishing

Titaniumdioxide Reinforced Glass-Ionomers with Different Surface Roughness Measurement Methods

Titaniumdioxide Reinforced Glass-Ionomers with Different Surface Roughness Measurement Methods

Characterization of Ni-Cu multilayers deposition on low carbon steel substrate using electroplating technique

Abstract Low carbon steel is widely used in oil and gas applications. In this research, multilayers of Nickel (Ni) and Copper (Cu) were deposited on a low carbon steel substrate using the electroplating process (ELP). Initially, a layer of Ni was coated, followed by a layer of Cu. ELP was implemented using water bath containing (300 g/l) of NiSO4.6H2O, (30 g/l) of (NiCl2.6H2O), (40 g/l) of H3BO3 and (30 g/l) of (NaCN), (30 g/l) of (CuCN), (10 g/l) of (NaOH.6H2O). First bath parameters were temperature is (59 - 60 °C), current density in the range of (3-5 A/dcm2), voltage was holed at (8 V) for Ni, and temperature was between (50-51 °C), current density in the range of (1-2 A/dcm2), voltage was holed at (4 V), while the plating time (10 minutes) for both Ni and Cu. The results refer to Ni, Cu, and Ni & Cu ELP thicknesses 3, 4.77 and 6.75 μm respectively. Metallurgical tests were achieve including the micro hardness of ELP, Vickers micro hardness results showed improvement in hardness values compared, with steel substrate, and in the presence of Ni, Cu, Ni+Cu layers, 322, 581, 479, and 562 Hv respectively. The roughness was measured using surface roughness measurement device. The average surface roughness (Ra) depicted satisfying values as a result of Ni layer coating, which gave uniform surface distribution with Ra 0.363 μm. X-ray diffraction (XRD) test examinations serve as strong evidence for the presence of Ni and Cu in the internal and external finish layers, respectively. Corrosion examinations were carried out in seawater solution (3.5 g NaCl) the corrosion behavior tends to be more resistance, with layers of Ni, and Cu in sea water environment, which is considered an important criterion to increase the part life.

Evolution of Lubrication Characteristics of Double-Nut Ball Screws Based on an Efficient Surface Roughness Modeling Method

Abstract Accurate prediction of lubrication characteristics, specifically film thickness and pressure distribution, is pivotal for ensuring optimal performance in ball screws. Despite its significance, there is a notable dearth of studies investigating the evolution of lubrication characteristics resulting from the changing surface roughness over prolonged operation of ball screws. Furthermore, obtaining the surface roughness of ball screws poses a challenge due to the limited loading capacity of measurement instruments. Traditional methods involving cutting the screw for surface roughness measurement are impractical for continuous monitoring during extended operation. To address this issue, the present study introduces an efficient approach to model the surface roughness of the raceway in double-nut ball screws. A profilometer is employed to measure profile roughness along two directions (parallel and perpendicular to the rolling direction) without the need to cut the screw raceway. The 2D power spectral densities and height probability densities of profile roughness are calculated to model the surface roughness, and the synthesized data are utilized to solve the Reynolds equation. The simulation method is validated through friction torque tests, demonstrating a calculation accuracy exceeding 92%. The study further explores the evolution of film thickness and pressure distribution in double-nut ball screws during running-in and steady wear stages, revealing severe asperity contact in the two nuts. Additionally, variations in load ratio, friction coefficient, and film thickness ratio (λ) are investigated. Considering the load ratio and λ of the slave nut, it can be inferred that boundary lubrication persists in the two nuts throughout the operation.

Surface roughness measurement in the notch area for estimating dynamic component load bearing capacity

The surface of a part can have an essential influence on its dynamic load bearing capacity as grooves and scratches act as more or less significant imperfections or additional micro-notches, depending on the interpretation. In order to accurately predict the fatigue strength, detailed knowledge of the surface structure in critical areas is essential but cannot always be established due to geometric constraints. To overcome these restrictions, a method utilizing impressions and a laser scanning microscope to take surface topography measurements in critical notch areas is used in this work. It enables precise and reproducible measurements to be taken. The method is used to conduct surface roughness measurements on fatigue strength specimens made of four different materials. Several roughness influence factors are calculated based on the results and their influence on the result of a recalculation using a fatigue strength assessment is shown as example. The calculated fatigue limit is compared against experimental results. The comparison shows significant scatter in prediction accuracy and no optimal surface influence factor can be recommended so far. It has to be noted that only a small sample of specimens, which were not designed for researching surface roughness influence in particular, were available for this work. The effects of roughness in the notch may not be completely captured by the available roughness influence factors. Furthermore, issues arise in the correct implementation of stress concentration factor based roughness influence factors. Further research is required to provide a more comprehensive understanding of the effects of surface roughness on the fatigue limit.

Design and Technological Aspects of Integrating Multi-Blade Machining and Surface Hardening on a Single Machine Base

Modern mechanical engineering faces high competition in global markets, which requires manufacturers of process equipment to significantly reduce production costs while ensuring high product quality and maximum productivity. Metalworking occupies a significant part of industrial production and consumes a significant share of the world’s energy and natural resources. Improving the technology of manufacturing parts with an emphasis on more efficient use of metalworking machines is necessary to maintain the competitiveness of the domestic machine tool industry. Hybrid metalworking systems based on the principles of multi-purpose integration eliminate the disadvantages of monotechnologies and increase efficiency by reducing time losses and intermediate operations. The purpose of this work is to develop and implement a hybrid machine tool system and an appropriate combined technology for manufacturing machine parts. Theory and methods. Studies of the possible structural composition and layout of hybrid equipment at integration of mechanical and surface-thermal processes were carried out, taking into account the basic provisions of structural synthesis and componentization of metalworking systems. Theoretical studies were carried out using the basic provisions of system analysis, geometric theory of surface formation, design of metalworking machines, methods of finite elements, and mathematical and computer modeling. The mathematical modeling of thermal fields and structural-phase transformations during HEH HFC was carried out in ANSYS (version 19.1) and SYSWELD (version 2010) software packages using numerical methods of solving differential equations of unsteady heat conduction (Fourier equation), carbon diffusion (2nd Fick’s law) and elastic–plastic behavior of the material. The verification of the modeling results was carried out using in situ experiments employing the following: optical and scanning microscopy; and mechanical and X-ray methods of residual stress determination. Formtracer SV-C4500 profilograph profilometer was used in the study for simultaneous measurement of shape deviations and surface roughness. Surface topography was assessed using a Walter UHL VMM 150 V instrumental microscope. The microhardness of the hardened surface layer of the parts was evaluated on a Wolpert Group 402MVD. Results and discussion. The original methodology of structural and kinematic analysis for pre-design studies of hybrid metalworking equipment is presented. Methodological recommendations for the modernization of multi-purpose metal-cutting machine tool are developed, the implementation of which will make it possible to implement high-energy heating with high-frequency currents (HEH HFC) on a standard machine tool system and provide the formation of knowledge-intensive technological equipment with extended functionality. The innovative moment of this work is the development of hybrid metalworking equipment with numerical control and writing a unique postprocessor to it, which allows to realize all functional possibilities of this machine system and the technology of combined processing as a whole. Special tooling and tools providing all the necessary requirements for the process of surface hardening of HEH HFC were designed and manufactured. The conducted complex of works and approbation of the technology of integrated processing in real conditions in comparison with traditional methods of construction of technological process of parts manufacturing allowed to obtain the following results: increase in the productivity of processing by 1.9 times; exclusion of possibility of scrap occurrence at finishing grinding; reduction in auxiliary and preparatory-tasking time; and reduction in inter-operational parts backlogs.

Study of resin coating adhesion on GFRP laminate surfaces after UV degradation

This paper describes research on the effect of UV radiation on the surface of a GFRP (Glass Fiber Reinforced Polymer) laminate in the context of increasing the adhesion between the laminate and polymer resin coatings. GFRP composite samples were prepared using the hand lay-up method. The samples were then exposed to various types of ultraviolet radiation (UVA, UVB, UVC) for 1000 h, with surface roughness measurements every 100 h. The flexural strength of laminates after photoaging was tested, which showed an increase in the strength of aged laminates compared to the reference sample by approximately 5–10 %. Coatings of various thicknesses were applied to the surface of the aged laminates and their adhesion to the substrate material was tested using the mandrel bending method alongside the cross-cut technique. The greatest change in surface roughness was observed on the sample exposed to UVC radiation, where the roughness increased approximately twice in relation to the reference sample. Coating adhesion tests have additionally shown that degradation under the influence of UVC has a positive effect on the adhesion of coatings to the laminate.

Simulation modeling of wafer grinding surface roughness considering grinding vibration

When using the workpiece rotation method to grind wafers, the grinding end vibration will deteriorate the surface roughness of the wafers. To study the impact law of vibration on the surface roughness of wafers during the grinding procedure, this paper presents a new approach to simulate and model the surface roughness of wafer grinding considering the grinding vibration. Firstly, the dynamics model under the consideration of grinding force was established for the grinding end of the grinding wheel and workpiece turntable. Secondly, using the iterative method to solve the dynamic equations that have been established, the vibration equation is obtained by fitting the displacement vibration curve of the end. Then, by reconstructing the surface grain of the gear teeth, a simulation model of wafer grinding surface roughness was established considering material removal, grain motion and grinding vibration. And then the grinding comparison test was conducted to compare the simulation and test surface roughness measurement results. The maximum deviation of the surface roughness Sz and Sa was 7.7 % and 5.4 %, respectively. The results indicate the accuracy of the modeling. Finally, based on the established wafer roughness model, explore the impact of vibration on wafer roughness during the grinding procedure. This model provides a reference for the research of wafer precision grinding technology.

A visual measurement method for grinding surface roughness combining filter and branch convolution network

ABSTRACT The visual measurement method of grinding surface roughness is mainly predicted by designing image feature indicators. In contrast, the self-extraction method of grinding surface features based on deep learning has problems such as noise, low resolution and poor perception of details. This paper proposes a visual measurement method for grinding surface roughness to address these problems by combining filters and branching convolutional networks. The method adopts a two-branch convolutional neural network, inputs the images using filter denoising and the original grinding workpiece surface images simultaneously, self-extracts roughness correlation features and fuses them to achieve feature enhancement, effectively improves the recognition accuracy and generalisation ability of the model, and verifies the robustness of the model in the case of rusting on the workpiece surface. The experimental results show that the method can effectively solve the problem of the grinding process’s weak and difficult recognition of surface roughness feature information and provide a basis for automated visual online measurement of grinding surface roughness.

Evaluation of nanohardness, elastic modulus, and surface roughness of fluoride-releasing tooth colored restorative materials.

Recently, interest in tooth-colored fluoride-releasing dental materials has increased. Although physical and mechanical properties such as surface hardness, elastic modulus and surface roughness of the restorative materials have been investigated, the effect of different immersion media on these properties is still controversial. The aim of this study was to evaluate the nanohardness, elastic modulus and surface roughness of the fluoride release of tooth-colored restorative materials after immersion in acidic beverages. Prepared samples of three restorative materials (a highly viscous glass ionomer (EQUIA Forte; GC, Tokyo, Japan), a compomer (Dyract XP; Dentsply, Weybridge, UK), and a bioactive restorative material (Activa BioACTIVE; Pulpdent, MA, USA)) were randomly divided and immersed in distilled water, a cola and an orange juice for one week. The HYSITRON T1 950 TriboIndenter device (Hysitron, USA) with the Berkovich diamond indenter tip was used for all measurements. The nanohardness and elastic modulus of the samples were measured by applying a force of 6000 μN to five different points on the sample surface. Surface roughness measurements were evaluated on random samples by scanning five random 40 × 40 μm areas. The properties were measured at the initial and one week after immersion. The values of nanohardness, elastic modulus and surface roughness were tested for significant differences using a two-way analysis of variance (ANOVA) with repeated measures (p < 0.05). Tukey's honest significant difference (HSD) test was used for multiple comparisons. AB (Activa BioACTIVE) had the highest initial mean values for nanohardness. After post-immersion, the highest mean value for elastic modulus was the initial AB value. The lowest mean value for roughness of 100.36 nm was obtained for the initial DX (Dyract XP) measurement. Acidic beverages had a negative effect on the nanohardness, elastic modulus and surface roughness of the restorative materials.

Shot peening effects on Cr-Mo-V steel: a comprehensive study of microstructure, surface roughness, residual stress, and mechanical behavior

This study presents a comprehensive study of the microstructure, mechanical characteristics, and surface roughness of Cr-Mo-V low alloy steels and a detailed investigation of the overall impact of shot peening (SP). The microstructure was examined using the optical and scanning electron microscope, showing a significant grain size decrease after shot peening. Evaluations of mechanical characteristics, such as microhardness and tensile strength, showed a noteworthy rise, suggesting enhanced material strength. Studies using fragmentography shed more light on changed fracture tendencies. X-ray diffraction technique (XRD) was used to measure residual stress distribution, and the outcomes displayed an increase after SP, which suggests that internal stresses were created. Surface roughness measurements also showed a noticeable decline, indicating better surface quality. The transformational effects of shot peening on Cr-Mo-V low alloy steels were highlighted by comparative investigations with base metals, providing insights into enhancing material performance for various engineering applications.

Scale-independent model based on fractal theory for calculating the adhesion force between a particle and rough surfaces.

The elimination of the scale-dependent statistical parameters is a challenge in the estimation of the van der Waals force between a particle and rough surfaces. Herein, a scale-independent parameter, the fractal dimension, was introduced into the Rabinovich model to calculate the microadhesion force. First, a Weierstrass-Mandelbrot function is proposed to generate a random 2D contour, which has a simplified form and is more reasonable for spectrum analysis. And then, the roughness scale extraction method was employed to calculate the fractal-dimension value of the real aluminum (Al) surface. And last, the proposed scale-independent Rabinovich-Fractal model was used to calculate the adhesion forces, which are consistent with the results of the atomic force microscopy adhesion test. Aside from providing a more accurate estimation of the van der Waals forces, the proposed model is not influenced by the sampling scale of the surface roughness measurement, which eliminates the related error in van der Waals force estimation.

Sand blasting for hydrophobic surface generation in polymers: Experimental and machine learning approaches

Wettability is a crucial surface feature of polymers due to their numerous interaction-destined applications. This study focuses on the application of sand blasting process for investigating the wettability of polymeric materials to produce hydrophobic behavior. Four different polymeric materials, Acrylonitrile Butadiene Styrene (ABS), Poly(methyl methacrylate) (PMMA), Polypropylene (PP), and Polycarbonate (PC) underwent sand blasting with varying process parameters, following a comprehensive plan for the design of experiments. Subsequent analyses included surface roughness measurement and wettability tests, supplemented by scanning electron and confocal microscopy observations to gain deeper insights into the blasted surfaces. A predictive model based on a machine learning algorithm was developed using the backpropagation technique to correlate the surface treatment parameters to surface roughness and wettability indexes. From the experimental results sand blasting proved to be efficient in creating hydrophobic surfaces on all the tested materials. The developed neural network demonstrated high fitting degrees between the predicted and measured values. ABS exhibited the most hydrophobic behavior and emerged as a strong candidate for further investigations.

The Abrasive Effect of Moon and Mars Regolith Simulants on Stainless Steel Rotating Shaft and Polytetrafluoroethylene Sealing Material Pairs.

For space missions to either the Moon or Mars, protecting mechanical moving parts from the abrasive effects of prevailing surface dust is crucial. This paper compares the abrasive effects of two lunar and two Martian simulant regoliths using special pin-on-disc tests on a stainless steel/polytetrafluoroethylene (PTFE) sealing material pair. Due to the regolith particles entering the contact zone, a three-body abrasion mechanism took place. We found that friction coefficients stabilised between 0.2 and 0.4 for all simulants. Wear curves, surface roughness measurements, and microscopic images all suggest a significantly lower abrasion effect of the Martian regoliths than that of the lunar ones. It applies not only to steel surfaces but also to the PTFE pins. The dominant abrasive micro-mechanism of the disc surface is micro-ploughing in the case of all tests, while the transformation of the counterface is mixed. The surface of pin material is plastically transformed through micro-ploughing, while the material is removed through micro-cutting due to the slide over hard soil particles.

Effect of Bond Coating Surface Morphology on the TBC System Lifetime

A study on the effect of bond coating (BC) surface modifications prior to ceramic deposition is presented. Grit blasting and polishing were used to modify the BC surface finish. Thermal barrier coating (TBC) systems were made of a commercial yttria-stabilized zirconia (YSZ) deposited by electron beam physical vapor deposition on a β-(Ni,Pt)Al-coated Ni-based single crystal superalloy. Surface roughness measurements and scanning electron microscopy observations, before and after thermal cycling at 1100 °C, were performed to investigate the influence of the initial surface treatment on the YSZ/BC interface morphology and top coat spallation resistance. Surface states enhancing TBC spallation resistance have been found. In particular, it is shown that rumpling can be avoided even in the presence of phase transformations in the BC, by grinding samples with P600 SiC paper or by applying an “heavy” grit blasting leading to a thinner BC.

Effect of acidic media on surface characteristics of highly filled flowable resin-based composites: An in vitro study.

To analyze and compare the impact of acidic media on the surface characteristics of highly filled flowable resin-based composites. Two hundred fifty-six specimens were divided into four groups: GUF (G-aenial Universal Flo), GUI (G-aenial Universal Injectable), TEF (Tetric EvoFlow), and FSF (Filtek Supreme Flowable Restorative). Surface characteristics were analyzed before (T0) and after specimens immersion in different media, such as gastric juice (GJ), fizzy drink (FD), citric juice (CJ), or artificial saliva (AS), for 9 h (T1) and 18 h (T2). The analyses included surface roughness (SR) measurements, where average roughness (Ra) was obtained, scanning electron microscopy (SEM) analysis, and surface hardness (SH) evaluation, with Vickers numbers (HV) reported. The differences in values among groups/subgroups within the same stage were assessed using two-way ANOVA and Tukey's post hoc test, whereas repeated measures ANOVA with Bonferroni post hoc test was performed to compare the changes in values through the stages. Data were presented as mean ± standard deviation (SD). At T0, GUI and GUF revealed lower Ra values (p < 0.05), more evenness in SEM micrographs, and higher HV values (p < 0.05) than FSF and TEF. At T1 and T2, specimens of all groups/subgroups demonstrated an increase in Ra and a decrease in HV compared with T0 (p < 0.05), as well as the changes in surface morphology on SEM micrographs. The lowest Ra and highest HV values were observed in GUI group, in contrast to FSF group, and in specimens immersed in GJ. GUI revealed lower SR and higher SH compared to GUF and FSF both before and after exposure to acidic media. The presence of acidic media, especially GJ, significantly increases SR and decreases SH of tested materials. Information on the changes in the surface characteristics of highly filled resin-based composites after exposure to acidic media may be essential for the longevity of restorations like composite veneers fabricated from these materials.

Hole quality geometrical measurement and surface roughness for α-Phase titanium alloy (α-Ti-6Al-4V) materials by using L-PBF (laser powder bed fusion) orthopedic implant application

This study examines the quality of circular-hole 3D-printed objects using laser powder bed fusion (L-PBF) on Ti-6Al-4V titanium alloy that typically used for orthopedic implants. Meanwhile measuring surface roughness and hole dimension deviations in AM specimens is very challenging. Thus, the specimens were printed with varying process parameters, followed by an L9 orthogonal array experiment, where parameters included laser power (LP) at 175, 185, and 195 W; scanning speed (SS) at 600, 900, and 1200 mm/s; and hatch distance (HD) at 70, 90, and 110 µm. Thus the, minimum surface roughness values are Ra 2.4 µm for the top surface and Ra 16.06 µm for the inside hole curve. Whereas the smallest hole deviations are 0.1102 mm for external and 0.2094 mm for internal diameters. Therefore, this analysis include FESEM, EDX, XRD, profilometry and stereomicroscopy. Where the best settings are LP 195 W, SS 900 mm/s, and HD 70 µm, producing well-fused, uniform α-phase Ti-6Al-4V specimens that are suitable for biomedical applications.

Evaluation of the anticorrosive painting procedure with reused abrasive for surface preparation – a case study

Atmospheric corrosion is a relevant cause of failure for many metallic structures. Its aggressiveness depends on environmental factors such as relative humidity, salinity, and contaminants. Anti-corrosion paint is the most used technique to minimize this problem, and surface preparation is a fundamental step for suitable paint adhesion. Abrasive blasting can remove oxides and old paint and texture the surface for receiving a new coating. An alternative to reduce costs is reusing abrasive particles to make the process more sustainable. In this investigation, an paint system was qualified through tests in its current environment. The influence of reused abrasives on the painting process by the paint layer’s thickness and its adhesion to the substrate was evaluated. Samples blasted with new and reused abrasives were prepared to evaluate the surface preparation process, allowing surface roughness measurements and incrustation analysis. It was possible to observe that the layers of paint were thin and not uniform, had approximately 155 μm thick, and defects such as pinholes. Reusing the abrasive did not affect the surface average roughness, which was 9.4 ± 2.5 μm. Abrasive incrustation and other contaminants such as Na, P, K, S, and Cl were found on new and reused abrasive surfaces. Recommendations for improvement and suggestions for changing the process were possible to assess.

Study on the impact of grinding variables on surface grinding of inconel 800

ABSTRACT Surface grinding is a widely employed finishing process in industrial sectors dedicated to achieve desired Surface characteristics of components. This study experimentally investigates the impact of the grinding parameters pertaining to the surface characteristics of Inconel 800, which is a nickel-iron-chromium alloy extensively used in high-temperature applications. Various commercially available grinding wheels were employed to grind Inconel800 under different grinding conditions. The ground surfaces were comprehensively analyzed using surface roughness measurements, Three-dimensional profilometry, optical microscopy, findings from XRD and SEM reveal that grinding parameters and wheel characteristics significantly impact the surface texture, topographical features, residual stress, and surface morphology of the machined nickel alloy.. The insights from this investigation contribute to the understanding of the grinding behavior of nickel-based superalloys and provide a basis for optimizing the grinding process for enhanced surface integrity. The findings are valuable for industries dealing with the machining of high-performance nickel alloy components.