Evaluation Of Roughness Research Articles

Effect of process parameters on the roughness and tensile behavior of parts manufactured by the metals LPBF process

AbstractThe laser powder bed fusion process for metals (LPBF‐M) results in the development of stochastic surface features that significantly influence the interactions between parts and their surrounding environment, as well as their mechanical properties. The process parameters influence the surface quality, which is quantified by the surface roughness. Therefore, customizing the surface roughness during the build process can significantly contribute to obtaining ready‐to‐use parts, reducing the need for extensive surface posttreatments. This paper utilizes theoretical estimations of melt pool depth under iso‐linear energy density, iso‐power, and iso‐temperature manufacturing process parameter conditions. These estimations are then compared with experimental evaluations of surface roughness and tensile strength in upright‐built specimens to extract the trends in terms of the input energy versus roughness, and the input energy versus tensile behavior. The results show that iso‐energy values yield similar roughnesses due to the consistent expected melt pool depth. Moreover, an increase in melt pool depth generates higher surface roughness, while smaller melt pool dimensions result in improved roughness. Additionally, a comparison between the melt pool size and tensile test performance reveals a detrimental impact on the tensile strength for specimens estimated to have smaller melt pool depths.

Potassium release and mitigation by additives in different biomass combustion systems

Deposition formation on heat-exchanging surfaces and corrosion limit the use and efficiency of solid biomass combustion systems. The main influencing factors on these ash-related problems are the potassium content, the form in which the potassium is bound to the fuel matrix, and the temperature in the combustion system. To avoid these deposition problems, choosing the right fuel for a particular combustion system and vice versa is important.In this work, the temperature in fluidized bed, grate firing, and suspension combustion systems is analyzed by using the example of the power plants Altenstadt and Avedøre, as well as a European municipal solid waste incineration plant. Additionally, the temperature-resolved potassium release of ten different biofuels is analyzed in an electrothermal vaporization unit (ETV) connected to an inductively coupled plasma optical emission spectrometer (ICP-OES). The potential of additives to mitigate the potassium release is analyzed by adding kaolin and coal fly ash to miscanthus, torrefied wood, and beechwood.The results show that hardly any potassium is released into the gas phase at the typical temperatures of fluidized bed systems. Most of the potassium release occurs between 1000 °C and 1400 °C, the typical temperature range of grate combustion systems. This shows that reducing the temperature of the fuel on the grate could drastically reduce the potassium release. However, due to the negative effect on the efficiency, other measures, such as using additives for capturing potassium species, are favored. At the temperatures in suspension-fired combustion systems, almost all potassium is released into the gas phase, and additives cannot mitigate the release at these temperatures. Additives can shift the potassium release of miscanthus and torrefied wood while showing no positive effect when mixed with beechwood.All in all, this work enables a quantitative comparison of various biofuels and a rough evaluation of the suitability of a fuel regarding the deposition formation for different combustion systems.

Evaluation of the barriers to and drivers of the incorporation of unmanned aerial vehicles into dam asset management

ABSTRACT Dam asset management entails the consistent evaluation of the state and usefulness of dams as tangible assets in terms of their expected lifespan, criticality, operational history, maintenance history, and long-term financing plan. This research aims to identify and evaluate the critical drivers and barriers associated with the use of unmanned aerial vehicles in dam asset management. This study uses rough decision-making trial and evaluation laboratory and interpretive structure modelling to analyze the interactions that take place between the barriers to and the drivers of unmanned aerial vehicles incorporation. To overcome the problem of vagueness, it develops rough set theory to determine the driving and dependence power of the drivers and the barriers, respectively. According to the findings, the most significant barrier to the incorporation of unmanned aerial vehicles into dam asset management is a lack of skilled operators, while the most significant driver of their incorporation is their cost-effectiveness. The findings of this study will be highly valuable to practitioners and government agencies working on the implementation of unmanned aerial vehicles in dam asset management, as they will enable them to correctly assess the different aspects of unmanned aerial vehicles incorporation.

Texture feature similarity-based roughness intelligent evaluation: a case study applied to milled surfaces

Surface roughness is of great significance in maintaining mechanical performance and improving the reliability of the equipment. However, fast surface roughness evaluations that are sufficiently stable and efficient for engineering in situ use have not yet been realized. To address this issue, an image-driven roughness intelligent method is proposed in this research. By evaluating the texture similarity intelligently between the testing image and the reference image, the surface roughness of the testing image can be acquired. Firstly, with a proposed adaptive texture extraction method, the texture feature of an image can be extracted even under a complex background. Secondly, by establishing the graph structure of the texture grayscale features, the similarity between different images is evaluated. Finally, by establishing a sparrow-optimized support vector machine regression method, the mapping relationship between the similarity and the surface roughness can be acquired. The experimental results indicate that the proposed method for intelligent evaluation of roughness has superior prediction performance (the average relative prediction error of Ra and Rz are 8.8156% and 8.0571%, respectively). Therefore, this work provides a useful tool for non-contact detection of workpiece surface roughness.

The pivotal role of the polyethylene glycol amount as compatibilizing on the morphological features of silica-based blends

Silica-based hybrid blends at different molecular or nanometer scale have gained a lot of interests from the technological point of view. In particular, several inorganic-organic hybrids find application in the biomedical field. In this context, inorganic SiO2 and hybrids made up of SiO2 and polyethylene glycol (PEG) have been synthesised via the sol-gel route and characterised from the morphological (throught the Atomic Force Microscopy - AFM) and spectroscopic point of view to shed light on their features as possible hybrid biomaterials. AFM investigation allowed for an effective quantitative evaluation of surface roughness of bioactive sol-gel-based materials. The results revealed an increase in material porosity as a function of the PEG amount in the systems, thus highlighting the pivotal role of the PEG amount as compatibilizing on the morphological features of silica-based blends. The co-presence of both the inorganic and organic phases was confirmed by the Fourier-transform infrared spectroscopy (FT-IR). Moreover, the influence of PEG was also investigated by analysing the deconvoluted FT-IR spectra in the range of 1600-750 cm−1.

Effect of Thermal Cycling or Simulated Gastric Acid on the Surface Characteristics of Dental Ceramic Materials

(1) Background: The presence of various dental ceramic materials with different chemical compositions complicates clinicians’ decision making, especially in cases with a highly acidic environment appearing in patients suffering from gastroesophageal reflux disease or other eating disorders. Thermal alterations in the oral cavity can also affect surface structure and roughness, resulting in variations in both degradation mechanisms and/or bacteria adhesion. The aim of the present in vitro study was to evaluate the effect of thermal cycling and exposure to simulated gastric acid on the surface roughness of different ceramics; (2) Methods: Five groups of different ceramics were utilized, and twenty specimens were fabricated for each group. Specimens were either thermocycled for 10,000 cycles in distilled water or immersed in simulated gastric acid for 91 h. The evaluation of surface roughness was performed with optical profilometry, while scanning electron microscopy, X-ray diffraction analysis and inductively coupled plasma atomic emission spectroscopy were also performed; (4) Conclusions: Based on the combination of the surface roughness profile and structural integrity, zirconia specimens presented the smallest changes after immersion in simulated gastric acid followed by lithium disilicate materials. Zirconia-reinforced lithium silicate ceramic presented the most notable changes in microstructure and roughness after both treatments.

Evaluation and Multi-Objective Optimisation of Cutting Parameters in Turning of AISI 1020 Mild Steel using Formulated Cutting Fluid

Input parameter like the cutting fluid is one of the requirements for minimal surface roughness, cutting temperature, tool wear and optimal material removal rate coupled with improved machinability and productivity. The evaluation of the optimal factors of surface roughness, material removal rate, cutting temperature and tool wear in the turning of AISI Mild Steel with the use of eco-friendly fluids. Concerns has been raise globally about the non - biodegradability and non-recyclability of the conventional fluids in the research space. This prompted the research interest in replacing the mineral oil based fluids with eco-friendly cutting fluid such as castor seed oil based cutting fluid (CBCF). The locally sourced castor seed oil was investigated for its physiochemical properties as well as its fatty acid composition (FAC). The cutting fluid was formulated using ratio 1:9 of oil with additives to distilled water and then characterized. In turning of AISI 1020 Mild Steel, the evaluation of surface roughness, material removal rate, cutting temperature and tool wear under the CBCF compared to the mineral oil based cutting fluid (MBCF) were carried out using Taguchi experimental design and Grey Relational Analysis (GRA) for multi-response optimization. The formulated cutting fluid showed pH value of 8.47, viscosity of 0.830 mm2/s, good resistance to corrosion, good stability and milkfish in colour. From the GRA, the multi-response optimal factor combination under the CBCF is (1250 rev/min) spindle speed, (0.6 mm/rev) feed rate and (1.0 mm) depth of cut, all at level 3 while under the MBCF, it also shows (1250 rev/min) spindle speed, (0.6 mm/rev) feed rate and (1.0 mm) depth of cut all at level 3. The parameters from Taguchi and GRA results are in agreement with results from other vegetable oil based fluids and this study also contributes and improves the science of machining.

Approach to Heterogeneous Surface Roughness Evaluation for Surface Coating Preparation

This paper focuses on evaluating the roughness of heterogeneous surfaces, aiming to interpret data effectively for thorough assessment. Previous research highlights the significant impact of surface roughness on final coatings. Beam-cutting machining generates surfaces with position-dependent roughness parameter changes. However, there is inconsistency in the methods for investigating roughness in such surfaces, leading to the loss of crucial information and potentially inaccurate results. This could result in flawed coating preparation and subsequent defects. This paper proposes a suitable evaluation method involving an optical 3D profilometer and a stabilizing support system for reliable measurements. It provides a detailed description of the materials and methods used. The objective is to establish a more consistent and accurate approach to assessing roughness for coating preparation. Technical applications demonstrate up-to-fivefold fluctuations in surface topography parameters, as illustrated in this manuscript. Overall, this paper seeks to address these challenges and provide a robust framework for evaluating roughness in heterogeneous surfaces, thereby enhancing surface coating preparation processes.

A study on the fabrication procedure for a high-D/Ti-ratio-deuterated-titanium film on the disk-type neutron generator target

This study aims to present thin film deposition and deuterium adsorption procedure to fabricate disk-type targets with high D/Ti values for a neutron generator and increase their lifespan. The neutron target consists of a titanium thin film with hydrogen loading, and a copper substrate for heat removal. We optimized the incident deuterium ion beam energy and thin film thickness using Geant4 simulations. Additionally, we calculated the expected neutron yield under the optimized conditions. The hydrogen adsorption conditions were optimized by comparing the H/Ti results as per hydrogen adsorption temperature and loading time using titanium foils of different thickness values. Hydrogen (or deuterium) adsorption ratio is strongly influenced by the surface condition and the deposition conditions of the thin film. A titanium film was deposited in various conditions of plasma DC power and substrate temperature. The quality of the thin film was evaluated through surface roughness evaluation and thin film sheet resistance for each deposition conditions. Subsequently, the hydrogen adsorption results were compared according to the quality of the thin titanium films, and the thin titanium film deposition conditions with the highest hydrogen adsorption ratio were confirmed. The selected conditions were applied to conduct deuterium adsorption. In conclusion, this study underscores the critical relationship between thin film quality and hydrogen (or deuterium) adsorption ratio, reinforcing the importance of optimizing thin film deposition parameters for the design of neutron generator disk-type targets with high quality of film and extended lifespan.

Surface Roughness of Polyetheretherketone Printed by Fused Deposition Modeling: A Pilot Study Investigating the Impact of Print Layer Thickness and Polishing Method

Polyetheretherketone is a high-performance thermoplastic polymer that can be used in 3D printing by fused deposition modeling, and is a promising material for dental applications. Some printing parameters are sensitive and can influence the properties of the printed object. Thus, this work aims to evaluate the influence of the print layer thickness on the surface roughness of polyetheretherketone before and after polishing and to verify the effectiveness of the polishing method used, as well as to compare it with the results obtained using polymethyl methacrylate as the control group. Specimens with different impression layer thicknesses were printed with polyetheretherketone (Group A—0.1 mm and Group B—0.3 mm). Additionally, a control group with polymethyl methacrylate specimens was milled. Roughness evaluation was conducted using a contact profilometer after the specimens had been printed (before polishing). Then, silicon carbide sandpaper was used to polish the surface, and the roughness was reassessed. Differences were observed between specimens regarding the print layer thickness and the roughness, with the 0.3 mm layer thickness showing the lowest roughness values. The results of this pilot study suggest that the surface roughness of fused deposition modeling printed polyetheretherketone is influenced by print layer thickness, with the lowest roughness seen at a thickness of 0.3 mm.

Root surface roughness evaluation following application of different periodontal instruments and Er:YAG laser: A profilometry and SEM study.

The aim of the present study was to evaluate the efficacy of 30°-angled Er:YAG laser tip and different periodontal instruments on root surface roughness and morphology in vitro. Eighteen bovine teeth root without carious lesion were decoronated from the cementoenamel junction and seperated longitidunally. A total of 36 obtained blocks were mounted in resin blocks and polished with silicon carbide papers under water irrigation. These blocks were randomly assigned into 3 treatment groups. In Group 1,30°-angled Er:YAG laser (2.94μm) tip was applied onto the blocks with a 20Hz, 120mJ energy output under water irrigation for 20s. In Groups 2 and 3, the same treatment was applied to the blocks with new generation ultrasonic tip and conventional curette apico-coronally for 20s with a sweeping motion. Surface roughness and morphology were evaluated before and after instrumentation with a profilometer and SEM, respectively. After instrumentation, profilometric analysis revealed significantly higher roughness values compared to baseline in all treatment groups(p < 0.05). Laser group revealed the roughest surface morphology followed by conventional curette and new generation ultrasonic tip treatment groups (p < 0.05). In SEM analysis, irregular surfaces and crater defects were seen more frequently in the laser group. Results of the study showed that the use of new generation ultrasonic tip was associated with smoother surface morphology compared to 30°-angled Er-YAG laser tip and conventional curette. Further in vitro and in vivo studies with an increased sample size are necessary to support the present study findings.

Evaluation of color change and surface roughness for two indirect esthetic materials submitted to different immersion protocol.

Evaluation of color change and surface roughness for two indirect esthetic materials submitted to different immersion protocol.

Surface Roughness Evaluation of Pre- Versus Post-Crystallization Polish of Two High-Strength Silicate Ceramics for Chairside CAD/CAM Technology

This in vitro study evaluated the surface roughness (Sa) of two high-strength silicate ceramics, lithium disilicate IPS e.max CAD, Ivoclar Vivadent (LDS group), and zirconia-reinforced lithium silicate Vita Suprinity, VITA Zahnfabrik (ZLS group). The surface roughness was investigated before and after milling using different polishing systems and timings relative to the final crystallization of the ceramics. Forty-eight samples per group were polished by a single calibrated operator using two polishing systems: Dialite LD (Brasseler) and Lithium Silicate Polishers (Meisinger) for the LDS group and Dialite LD (Brasseler) and Vita Suprinity Polishing Set Technical (VITA Zahnfabrik) for the ZLS group, both pre- and post-crystallization. Surface roughness was measured using a confocal laser microscope (OLS4000 LEXT/Olympus), with scanning electron microscopy (SEM) used to evaluate surface morphological changes. Significant differences in Sa values were found between baseline groups, with ZLS exhibiting lower values. All polishing methods significantly reduced surface roughness compared to baseline (p ≤ 0.05). No significant differences were found in LDS samples when polishing pre- or post-crystallization (p = 0.129), while for ZLS samples, post-crystallization polishing achieved significantly smoother surfaces (p &lt; 0.001). The study concluded that the choice of polishing system and timing did not significantly affect surface roughness for LDS. However, it is recommended that post-crystallization polishing be performed for the optimal smoothness of ZLS. This study aimed to evaluate the post-milling polishing procedures of CAD/CAM high-strength restorations, emphasizing the importance of an optimal surface roughness to prevent issues such as increased risk of abrasion on opposing teeth, enhanced plaque adhesion, and mechanical failures. Investigating these polishing techniques enables clinicians to optimize clinical performance, thereby improving the quality and longevity of high-strength silicate ceramics.

Tribological Improvement of Low-Viscosity Nanolubricants: MoO3, MoS2, WS2 and WC Nanoparticles as Additives

The aim of this research is studying the tribological performance of MoO3, MoS2, WS2 and WC nanoparticles as additives of PAO4. Pure sliding tribological tests were performed at 120 °C, finding outstanding friction and wear reductions in comparison with the PAO4, with maximum friction reductions of 64% for the 0.1 wt% MoS2 nanolubricant and greatest wear decreases for 0.1 wt% MoS2 nanolubricant: a width reduction of 62% and a worn area decrease of 97%. Raman mapping and a roughness evaluation of the worn pins confirmed the tribofilm formation and mending as tribological mechanisms. Rolling–sliding tests were conducted with best nanolubricants performance in pure sliding, observing excellent antifriction capabilities of MoS2 nanoparticles at low speeds, indicating that the use of nanoparticles is vital in boundary lubrication.

The evaluation of machining performances and surface roughness of TZM-molybdenum superalloy processed by silicon carbide powder mixed EDM process using RSM and ANOVA

In the present era, the concept of Industry 4.0 plays a significant part in improving the efficiency, quality, and utilization of resources by automation and enabling intelligent operations in manufacturing processes. As a result, there is a requirement to develop an environment that improves efficiency as well as quality in order to accomplish net zero in manufacturing. The objective of powder mixed electric discharge machining (PMEDM) is to enhance the quality of the surface and machining efficiency of traditional electrical discharge machining. The PMEDM method was applied to TZM-molybdenum superalloy in the present investigation by incorporating silicon carbide particles into the dielectric medium. Powder concentration, peak current, pulse on time, pulse off time, and gap voltage were the considered input variables for the investigation. The impacts of the input variables on the surface of the specimen’s roughness and the rate of material removal (MRR) were examined. The experiment model was built using response surface methodology. To find out if the input factors were significant with regard to each response, an analysis of variance (ANOVA) was performed. Powder concentration, pulse current, gap voltage, and pulse on time are found to be the important input variables for both surface roughness and MRR based on ANOVA analysis.

Prediction of milling surface roughness based on DGLCM and neural network

With the manufacturing industry’s increasingly automated and intelligent development, traditional workpiece roughness measurement methods can no longer meet the requirements for short time, high efficiency, and online measurement. Therefore, this article proposes a roughness evaluation model for vertical milling workpiece roughness measurement and improves upon the traditional Gray Level Co-occurrence Matrix (GLCM) method to achieve high accuracy and robustness in measuring milling surface roughness. First, the milled surface is illuminated by a coaxial light source, and an image is captured using an industrial camera and a telecentric lens. Then, four features of the image are extracted using the Direction Measure-based Gray Level Co-occurrence Matrix (DGLCM) to construct a feature descriptor. Finally, Finally, create an RBF network to predict surface roughness. Through experimental comparison with traditional GLCM feature extraction methods, our proposed feature extraction method has a prediction error of only 2.01%, which is superior to traditional methods.

The Wavelet Transform for Feature Extraction and Surface Roughness Evaluation after Micromachining

Miniaturization is a dominant trend in machine building which requires the use of advanced techniques of manufacturing and control. Apart from dimensional and shape precision of miniaturized components, surface geometry, particularly roughness and so-called microroughness that results from the use of advanced treatment techniques, plays an important role in correct assembly, reliable operation and durability of the whole machine. The selection of filtration method in surface geometry of micro-objects can be a substantial problem. The authors of the paper propose to use wavelet filtration in digital processing of a point cloud to remove measurement noise and not to change the surface character of the measured object. Also, the authors propose, in this paper, some criteria for selecting the number of wavelet filtration levels based on minimalization of the RMS value. It is supposed to improve the efficiency of low-pass filtration of small areas of the surface, particularly compared to traditional λs Gaussian filtration.

Evaluation of the surface roughness and dimensional accuracy of low-cost 3D-printed parts made of PLA–aluminum

Fused deposition modeling (FDM) is currently used in several fields, such as architecture, manufacturing, and medical applications. FDM was initially developed to produce and create prototypes, but the expense appears excessive for producing final products. Nevertheless, in this day and age, engineers have developed a low-cost 3D printer. One of the major issues with low-cost 3D printers is the low dimensional accuracy and high tolerances of the printed products. Herein, different printing parameters, i.e., layer thickness, printing speed, and raster angle, need to be investigated to enhance the surface roughness of the parts produced using FDM. Thus, the present study focuses on investigating the performance of the surface finish produced by FDM by manipulating different parameters such as layer thickness, printing speed, and raster angle. Taguchi's method, based on the L9 array for experimental design, was employed to elucidate the response variables. The sample model was developed following ISO standards, utilizing polylactic acid (PLA)–aluminum as the filament material. The analysis of variance results indicated that the layer thickness and raster angle significantly affect the surface roughness of the printed parts, with statistical P-values of 0.016 and 0.039, respectively. This enables an easy selection of the optimal printing parameters to achieve the desired surface roughness. The dimensional accuracy of the fabricated part was also evaluated. Thirteen dimensions of the part features were analyzed, and the results showed that the FDM machine exhibited good accuracy for most of the shapes, with a deviation below 5%.

Investigation on evaluation and prediction of surface roughness and terahertz reflectivity analysis of the SiCp/Al composites component by diamond turning

SiCp/Al composites are suitable for satisfying the lightweight requirements of terahertz wave-reflecting components. In this paper, diamond-turned surfaces of 60 % high volume fraction SiCp/Al composites are characterized in terms of surface roughness and terahertz reflectivity. The finished surfaces of SiCp/Al composites are obtained using single-point diamond turning with different process parameters, and surface roughness measurements as well as SEM and EDS analyses are conducted on the surfaces. The theoretical relationship between surface roughness and terahertz reflectivity is analyzed, and terahertz reflectivity testing experiments are conducted and validated. The surface roughness evaluation system and prediction model for SiCp/Al composites with a volume fraction of 60 % are established, and the errors between the experimental results and the predicted results are verified within 10 % by random experiments. Finally, the turning process parameters are optimized using a genetic algorithm, and the optimized turning process parameters are obtained as the spindle speed of 750 r/min, the feeding speed of 1 mm/min and the turning depth of 6 μm.

Tribological behavior of electric vehicle transmission oils using Al2O3 nanoadditives

Antifriction and antiwear performances of Al2O3 nanoparticles (NPs) as additives of an automatic transmission fluid, ATF, are presented in this research. For this purpose, four nanodispersions were formulated: ATF + 0.05 wt% Al2O3 NPs, ATF + 0.10 wt% Al2O3 NPs, ATF + 0.15 wt% Al2O3 NPs and ATF + 0.20 wt% Al2O3 NPs to identify the optimal concentration of additive. Tribological experiments were taken at pure sliding conditions, with the formulated nanolubricants and the ATF, under a working load of 20 N. The four nanolubricants tested resulted in lower friction coefficients than those obtained using ATF, reaching a maximum reduction of 6 % with the ATF + 0.10 wt% Al2O3 nanolubricant. The tribological pairs tested with the Al2O3 nanolubricants show lower wear than those tested with the ATF, having the best wear decrease with the ATF + 0.10 wt% Al2O3 nanolubricant, with reductions of 45, 57 and 78 %, respectively, in diameter, depth and area of the wear scar. Furthermore, by means of confocal Raman microscopy, roughness evaluation and SEM-EDX of the worn tribological specimens, it can be determined that mending, tribo-sintering as well as rolling mechanisms occur.