Surface Roughness Parameters Research Articles

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.

Investigating Fracture Behavior in Titanium Aluminides: Surface Roughness as an Indicator of Fracture Mechanisms in Ti-48Al-2Cr-2Nb Alloys

Titanium aluminides, particularly the Ti-48Al-2Cr-2Nb alloy, have drawn significant attention for their potential in high-temperature aerospace and automotive applications due to their exceptional performances and reduced density compared to nickel-based superalloys. However, their intermetallic nature poses challenges such as limited room-temperature ductility and fracture toughness, limiting their widespread application. Additive manufacturing, specifically Electron Beam Melting (EBM), has emerged as a promising method for producing complex-shaped components of titanium aluminides, overcoming challenges associated with conventional production methods. This work investigates the fracture behavior of Ti-48Al-2Cr-2Nb specimens with different microstructures, including duplex and equiaxed, under tensile and high-cycle fatigue at elevated temperatures. Fracture surfaces were analyzed to distinguish between static and dynamic fracture modes. A novel method, employing confocal microscopy acquisitions, is proposed to correlate surface roughness parameters with the causes of failure, offering new insights into the fracture mechanisms of titanium aluminides. The results reveal significant differences in roughness values between the propagation and fracture zones for all the temperatures and microstructure tested. At 650 °C, the crack propagation zone exhibits lower Sq values than the fracture zone, with the fracture zone showing more pronounced roughness, particularly for the equiaxed microstructure. However, at 760 °C, the difference in Sq values between the propagation and fracture zones becomes more pronounced, with a more substantial increase in Sq values in the fracture zone. These findings contribute to understanding fracture behavior in titanium aluminides and provide a predictive framework for assessing structural integrity based on surface characteristics.

Effect of Depth of Cut and Number of Layers on the Surface Roughness and Surface Homogeneity After Milling of Al/CFRP Stacks.

A multilayer structure is a type of construction consisting of outer layers and a core, which is mainly characterized by high strength and specific stiffness, as well as the ability to dampen vibration and sound. This structure combines the high strength of traditional materials (mainly metals) and composites. Currently, sandwich structures in any configurations (types of core) are one of the main directions of technology development and research. This paper evaluates the surface quality of II- and III-layer sandwich structures that are a combination of aluminum alloy and CFRP (Carbon Fiber-Reinforced Polymer) after the machining. The effect of depth of cut (ae) on the surface roughness of the II- and III-layer sandwich structures after the milling process was investigated. The surface homogeneity was also investigated. It was expressed by the IRa and IRz surface homogeneity indices formed from the Ra and Rz surface roughness parameters measured separately for each layer of the materials forming the sandwich structure. It was noted that the lowest surface roughness (Ra = 0.03 µm and Rz = 0.20 µm) was obtained after the milling of the II-layer sandwich structure using ae = 0.5 mm, while the highest was obtained for the III-layer structure and ae = 1.0 mm (Ra = 1.73 µm) and ae = 0.5 mm (Rz = 10.98 µm). The most homogeneous surfaces were observed after machining of the II-layer structure and using the depth of cut ae = 2.0 mm (IRa = 0.28 and IRz = 0.06), while the least homogeneous surfaces were obtained after milling of the III-layer structure and the depths of cut ae = 0.5 mm (IRa = 0.64) and ae = 2.0 mm (IRz = 0.78). The obtained results may be relevant to surface engineering and combining hybrid sandwich structures with other materials.

The Effect of the Chamber-Filling Ratio in Vibratory Shot Peening on Selected Surface Layer Properties of 30HGSA.

This study investigated the influence of the filling ratio of the working chamber and ball diameter in vibratory shot peening (VSP) on select properties of the surface layer. The tested material was 30HGSA steel, which is effectively used in the aviation industry. The following were analyzed: the surface roughness parameters, the shape of the Abbott-Firestone curve, the bearing area ratio Smr(c=50%), the microhardness distribution, the microhardness on the surface, and the residual stress σ on the surface. A change in the ratio of peaks and valleys in the maximum height of the profile was observed. After VSP, the valleys were dominant over the peaks. The most favorable values of the analyzed roughness parameters (Sz, Sp, and Sv) were obtained for d = 9.4 mm and kd = 33%. The bearing area ratio Smr(c=50%) was approximately 50 times higher than before VSP (the most favorable for d = 9.4 mm and kd = 33%). The largest thickness of the strengthened layer of 200 μm and the greatest increase in the microhardness equal to ΔHV 0.05 = 109 were obtained after VSP was conducted using the ball diameter d = 14.3 mm kd = 33%. Regardless of the VSP conditions, the absolute value of compressive stresses increased; the highest σ stresses were obtained for d = 3.0 mm and kd = 33%, and they were 88% higher than before the treatment. It was concluded that the recommended chamber-filling ratio for beneficial properties is kd = 33%.

Influence of magnetic field on the surface structure and properties of germanium single crystals

The results of experimental studies using optical profilometry and scanning probe microscopy of the structure and surface parameters of germanium single crystals exposed to an alternating magnetic field are presented. The change in parameters of surface roughness and relief of single crystals after treatment by magnetic field was found. Using optical spectroscopy, a decrease in transmittance in the range of 1.8—23 μm was established, due to the influence of an alternating magnetic field, leading to a change in the surface topography.

Characterization of Composites from Post-Consumer Polypropylene and Oilseed Pomace Fillers.

This study investigates the properties of composites produced using post-consumer polypropylene (PP) reinforced with lignocellulosic fillers from Nigella sativa (black cumin) and rapeseed pomace. Using agri-food by-products like pomace supports waste management efforts and reduces the demand for wood in wood-plastic composites. The composite production method combined extrusion and hot flat pressing. Mechanical tests showed a decrease in the tested parameters. Compared to the control variant, the MOE decreased by 26.4% (PP_R variant) and 46.9% (PP_N variant), and the MOR value decreased by 78.7% (PP_N) and 55.1% (PP_R). No significant differences in surface roughness parameters were observed. The composite with nigella particles demonstrated increased wettability. TGA tests showed reduced thermal stability compared to PP and differences between composite variants. The composites exhibited susceptibility to fungal overgrowth, which suggests potential biodegradability. The composites demonstrated complete overgrowth by inoculated fungi, reaching 100% coverage, while samples from PP known to be resistant to biological factors remained unaffected. Although the mechanical properties of the composites were degraded, the use of lignocellulosic fillers offers undeniable advantages, such as waste management of lignocellulosic and polypropylene byproducts, reduced wood demand, and the potential biodegradability of the obtained composites. However, there is a need for further optimization of manufacturing processes and material composition to enhance the material performance.

The Use of Graphite Micropowder in the Finish Turning of the Ti-6Al-4V Titanium Alloy Under Minimum Quantity Lubrication Conditions.

The use of the minimum quantity lubrication (MQL) method during machining leads to the reduced consumption of cooling and lubricating liquids, thus contributing to sustainable machining. To improve the properties of liquids used under MQL conditions, they are enriched with various types of micro- and nanoparticles. The purpose of this study was to investigate the effect of the addition of graphite micropowder (GMP) on tool life, cutting force components, and selected surface roughness parameters during the finish turning of the Ti-6Al-4V titanium alloy under MQL conditions. The addition of 0.6 wt% of GMP to the base liquid in machining under MQL conditions leads to an extension of tool life by 7% and 96% compared to machining with a liquid without the addition of GMP and dry machining, respectively. Mathematical models of the cutting force components and surface roughness parameters were developed, taking into account the change in cutting speed and feed. It was found that the use of a liquid with the addition of GMP extends the range of cutting parameters for which the shape of chips obtained is acceptable in terms of work safety. The novelty of this study lies in the use of a cutting fluid composed of bis(2-ethylhexyl) adipate and diester, enriched with graphite micropowder, which has not been extensively investigated for machining titanium alloys under MQL conditions.

Experimental testing of roughness parameters during vibratory lapping of flat surfaces

The basic design parameters and operational conditions of an enhanced vibratory lapping machine are considered. The main purpose of the research is to define the influence of different machining regimes on the roughness parameters of flat surfaces of parts made of C22 steel. The experiments are carried out at different controllable conditions of the vibratory lapping process: amplitudes of vibrations of the upper lap, forced frequencies, machining durations, and lapping paste types. The obtained results are shown in the form of bar charts describing the dependencies of the surface roughness on the machining conditions mentioned above. The major scientific novelty consists in the further development of the technologies of lapping and polishing of flat surfaces using vibratory machines with an electromagnetic drive. The presented research can be used by engineers and technologists while improving existent designs of vibratory lapping-polishing machines, as well as enhancing the corresponding machining processes.

Characteristics of rolling interface lubrication considering contact surface textures in mixed lubrication

This study comprehensively utilizes the mixed lubrication theory and rolling deformation theory to establish a finite element stiffness contact model that considers the surface texture characteristics of the rolling interface. The dynamic explicit finite element analysis is used to obtain the deformed solid, and the turbulent equation is used to control the fluid boundary conditions. The bidirectional Fluid-Structure Interacton (FSI) ansysis is used to study the influence of surface roughness, surface textures, and rolling parameters such as rolling speed on the distribution of oil film pressure and contact characteristics during the rolling process. The results confirm that transverse texture reduces the friction coefficient and dynamic pressure by enhancing the trapping effect of rough peaks and facilitating the entrainment of the fluid film. Under the same textural conditions, the contact area decreases with increasing roughness while the friction coefficient increases. As the rolling speed increases, the rolling pressure decreases to a certain extent, and the contact area ratio will decrease; Lubricants with higher viscosity can effectively reduce the friction and rolling force at the rolling interface. We believe that the insights obtained from the numerical simulations provided in this reaserch will lay a theoretical foundation for subsequent research on plate shape control.

ASSESSMENT OF THE ROOT MEAN SQUARE DEVIATION ON SURFACES MACHINED BY HIGH-FEED TANGENTIAL TURNING

Recent advancements in machining focus on precision, efficiency, and handling harder materials, driven by sectors like aerospace and automotive. Hard machining, or processing materials over 45 HRC, presents challenges such as rapid tool wear, intense heat, and maintaining dimensional accuracy. Innovations in cutting tool materials and CNC technology have improved these processes, but tool degradation and high forces still complicate machining hardened materials. Surface roughness is a key quality metric, impacting performance factors like wear resistance and fatigue life. By optimizing cutting parameters, manufacturers aim to achieve consistent surface finishes, essential for durability in demanding applications. In this paper, the effect of the input parameters (depth of cut, feed, and cutting speed) are analysed on selected surface roughness parameters. The setup parameters were selected according to the full factorial design of experiment method. The results showed that higher feed rates resulted in rougher finishes, leading to greater spacing between profile elements and steeper surface profiles in the studied range.

The Influence of CLSM Magnification on the Measured Roughness of Differently Prepared Dental Materials.

This in vitro study investigated how varying magnifications (5×, 10×, 20×, and 50×) using a confocal laser scanning microscope (CLSM) influence the measured surface roughness parameters, Ra/Sa and Rz/Sz, of various materials with two surface treatments. Cylindrical specimens (d ≈ 8 mm, h ≈ 3 mm, n = 10) from titanium, zirconia, glass-ceramic, denture base material, and composite underwent diamond treatment (80 μm; wet) and polishing (#4000; wet; Tegramin-25, Struers, G). The surface roughness parameters (Ra/Sa, Rz/Sz) were measured with a CLSM (VK-100, Keyence, J) at 5×, 10×, 20×, and 50× magnifications. Line roughness (Ra/Rz) was measured along a 1000 μm distance in three parallel lines, while area roughness (Sa/Sz) was evaluated over a 2500 μm × 1900 μm area. The statistical analysis included ANOVA, the Bonferroni post hoc test, and Pearson correlation (SPSS 29, IBM, USA; α = 0.05). Ra/Sa and Rz/Sz showed significant differences (p ≤ 0.001, ANOVA) across magnifications, with values decreasing as magnification increased, highest at 5× and lowest at 50×. Titanium, zirconia, and glass-ceramic showed significant measured roughness values from 5× to 50×. Denture base material and composite had lower measured roughness values, especially after polishing. Line and area roughness varied significantly, indicating that magnification affects measured values. Standardizing magnifications is essential to ensure comparability between studies. A 50× magnification captures more detailed profile information while masking larger defects.

2D and 3D surface roughness parameters of surfaces machined by EDM

In electro discharge machining (EDM or spark erosion) the roughness of the machined surface plays a very important role in the applicability of the process. The EDM machined surfaces are near isotropic, so the 3D measured surface roughness parameters can be compared to the parameters measured by 2D method. This paper reports on the results of research on the comparison of 2D and 3D surface roughness parameters of EDM machined surfaces of tool steels. Based on the results of the performed cutting experiments and the subsequent measurements, conclusions will be drawn regarding the connection between the 2D and 3D surface parameters and the extent of roughness of steel surfaces machined by two type electrode material.

Impact of cutting parameters on surface roughness in aluminum alloys machining: a review of machine learning models for key parameter identification

This paper provides a comprehensive review of research on the influence of machining parameters—depth of cut, feed rate, and cutting speed—on surface roughness, with a focus on aluminum alloys. Surface quality in CNC machining is significantly affected by these parameters, with numerous studies highlighting their impact on achieving desired surface roughness. The review analyzes findings from ten studies, emphasizing that feed rate is generally identified as the most influential parameter for surface roughness. While feed rate shows a dominant effect, cutting speed and depth of cut also contribute, though to a lesser extent. The research includes a discussion of various methodologies, including ANOVA, the Taguchi method, and more simple machine learning regression models, which demonstrate strong alignment with experimental results and highlight the effectiveness of advanced regression-based models in predicting surface roughness. The study concludes that optimizing feed rate is crucial for achieving high surface quality values, while cutting speed and depth of cut should be managed appropriately. The findings underscore the importance of machine learning tools in analyzing and optimizing machining parameters, offering practical guidance for CNC machine operators and engineers.

Yarn‐to‐Yarn Surface Area and Roughness as Structural Engineering Tools for Optimizing the Electrical Output of Triboelectric Nanogenerators: Geometrical and Experimental Verification

AbstractThis paper investigates the performance of woven triboelectric nanogenerators (W‐TENGs) fabricated with different fabric patterns, specifically plain, twill, and hopsack weaves, using wool and polyester yarns. It is intended to enhance the electrical output and efficiency of W‐TENGs for potential applications in wearable electronics by optimizing the weaving pattern. Results indicate that W‐TENGs with twill 2/2 and hopsack 2/2 patterns exhibit superior electrical outputs, attributed to their higher contact surface area and roughness. The twill 2/2 pattern demonstrates the highest electrical output, generating an open‐circuit voltage of 4.7 V, a short‐circuit current of 4 µA, and a transferred charge of 0.35 µC. This study also highlights the critical role of surface area and dielectric material roughness in determining the output performance of triboelectric structures. A theoretical model is developed to calculate the real contact surface area of the woven fabrics with different patterns. Statistical analysis reveals significant relationships between surface roughness parameters and electrical performance. Dynamic testing under varying contact forces and frequencies demonstrates the practical applicability and robustness of the W‐TENGs. Furthermore, the devices exhibit excellent durability, maintaining stable performance over extended periods. This research provides new insights into fabric design strategies for optimizing energy harvesting in wearable devices.

Grey Relationship Analysis of Cutting Forces and Surface Roughness in Turning using Cryo-treated and Untreated Cutting Tools

The aim of this experimental study is to establish the optimum heat treatment procedure and machining parameters to obtain values of cutting force and surface roughness in machining AISI 1050 workpiece by utilizing grey relations analysis based on Taguchi method. In this regard, machining operations were carried out at three different cutting speeds and three different feed rates at a constant depth of cut. Taguchi mixed-level design L18 (2^2 3^2) was chosen for machining experiments. The optimum heat treatment and machining parameters for determination of cutting force and surface roughness values were identified according to the fact that higher the Signal/Noise ratio is better based on grey relations analysis of Taguchi method. The results showed that the optimum parameters for surface roughness and cutting forces were obtained as 0.1 mm/rev at feed rate and 180 m/min at cutting speed with cryo-treated cutting tool. According to ANOVA table and Signal/Noise ratios, it was specified that the most effective parameters on cutting forces and surface roughness were feed rate, cutting speed and heat treatment conditions, respectively.

Atomic Force Microscopic Evaluation of Surface Topographies of Various Rotary Files in Root Canal Preparation in Molar Teeth

ABSTRACT Background: The efficiency and safety of root canal preparation are significantly influenced by the surface topographies of rotary files. Atomic force microscopy (AFM) provides high-resolution imaging that can reveal detailed surface characteristics of these instruments. Materials and Methods: In this study, three types of rotary files (File A, File B, and File C) were used to prepare the root canals of extracted human molar teeth. A total of 30 molar teeth were divided into three groups (n = 10) and prepared using one of the three rotary files. After preparation, the rotary files were analyzed using AFM to measure surface roughness parameters including average roughness (Ra), root mean square roughness (Rq), and maximum peak height (Rp). Statistical analysis was performed using ANOVA and post hoc tests to compare the differences between the groups. Results: The AFM analysis revealed significant differences in the surface topographies of the rotary files. File A exhibited a Ra of 150 nm, a root mean Rq of 180 nm, and a maximum peak height Rp of 300 nm. File B showed an average roughness (Ra) of 200 nm, a root mean Rq of 230 nm, and a maximum peak height (Rp) of 350 nm. File C had an average roughness (Ra) of 170 nm, a root mean Rq of 210 nm, and a maximum Rp of 320 nm. Statistical analysis indicated that File B had significantly higher roughness parameters compared to File A and File C (P < 0.05). Conclusion: The surface topographies of rotary files vary significantly, which may impact their performance in root canal preparation. File B, with the highest roughness parameters, may pose a greater risk of canal wall damage and debris retention. These findings underscore the importance of selecting appropriate rotary files to optimize endodontic treatment outcomes.

Investigation of Silver- and Plant Extract-Infused Polymer Systems: Antioxidant Properties and Kinetic Release.

This study evaluated the impact of silver particles, suspended in Arnica montana flower extract, on the physicochemical characteristics and release dynamics of antioxidant compounds in PVP (polyvinylpyrrolidone)-based hydrogel systems. The hydrogels were synthesized via photopolymerization with fixed amounts of crosslinker (PEGDA) and photoinitiator, while the concentration of the silver-infused extract was systematically varied. Key properties, including the density, porosity, surface roughness, swelling capacity, and water vapor transmission rate (WVTR), were quantitatively analyzed. The results demonstrated that increasing the silver content reduced the hydrogel density from 0.6669 g/cm3 to 0.2963 g/cm3 and increased the porosity from 4% to 11.04%. The surface roughness parameters (Ra) rose from 8.42 µm to 16.33 µm, while the WVTR increased significantly from 65.169 g/m2·h to 93.772 g/m2·h. These structural changes directly influenced the release kinetics of antioxidant compounds, with kinetic modeling revealing silver-dependent variations in the evaluated release mechanisms. This innovative approach of integrating silver particles and plant-derived antioxidants into hydrogels highlights a novel pathway for tailoring material properties. The observed enhanced porosity and moisture regulation underscore the hydrogels' potential for biomedical applications, particularly in wound care, where controlled moisture and antioxidant delivery are critical. These findings provide new insights into how silver particles modulate hydrogel structures and functionalities.

Tool wear and surface topography shaping after TPl multi-axis milling of Ni-based superalloy of the torus milling cutter using the strategy of adaptive change of the active cutting edge segment

This paper details an investigation of the process of multi-axis high-speed milling of the surface of Ni-based superalloy Inconel 718 parts used the torus milling cutter. Presents the issues and development of the own models of the multi-axis milling in a kinematic variant of the TPl (Tool Pulling) type in terms of tool wear. Because the cutting speed in finishing high-speed milling is the parameter with the greatest influence on tool life and surface roughness, the dependence of the variation of the cutting speed at the torus part of the cutter was first determined as a function of the distance from the tip point along the axial direction and the geometrical parameters of the torus. A model for multi-axis milling of the TPl type was developed and described in a simplified manner, which forms the basis of an own ACACES strategy for segmenting the cutting edge of a torus milling cutter. The adaptation of a given segment to the active cutting edge during machining was based on tool wear and kinematic roughness criteria. Simulations and experiments of multi-axis milling were carried out, and the necessary analyses were performed. In this paper, in addition to testing an in-house strategy for multi-axis milling used the torus milling cutter, the problem of defining the cutting speed in relation to the nominal diameter and effective diameter of the tool is investigated for the first time. In addition, wear measurement was carried out using an in-house methodology, taking full advantage of the capabilities of the multi-axis machining centre, which significantly reduced measurement time and positively influenced the effectiveness of tool life assessment. Using the own ACACES strategy of the multi-axis surface milling of parts made of Ni-based superalloys, an almost fourfold increase in torus cutter life was achieved compared to the conventional strategy, while maintaining the required machined surface roughness parameters.

Retrieval of soil moisture in salinized farmland soil by multi-polarization SAR

ABSTRACT Synthetic Aperture Radar (SAR) is a potent instrument for estimating soil moisture across vast farmland areas. However, when soil salinity rises, existing SAR retrieval models for soil moisture become less accurate. Soluble salts in soil water alter the inherent correlation between the SAR backscattering coefficients and soil water, thus compromising the performance of retrieval models. The need to get surface roughness parameters from the field also limits the widespread application of the model. To address these issues, we developed a retrieval model for salty soil moisture assessment under small-scale roughness surfaces. First, we found a method to distinguish between slightly rough and rough surfaces using scattering entropy obtained from full-polarization decomposition. Then, we harnessed the co-polarization ratio to mitigate the effect of surface roughness in slightly rough conditions. Later, we developed a soil moisture retrieval model based on the co-polarization ratio, considering incidence angle, residual roughness, and soluble salt content. The validation of the model was verified using field surveying data, yielding an RMSE of 0.026 cm3 ·cm− 3 for the estimated soil moisture. This accuracy is comparable to or surpasses the level achieved by SAR for non-salinized soil moisture retrieval. Our findings showed that Scattering entropy is an effective parameter for distinguishing scattering mechanisms on farmland surfaces effectively. Specifically, when the scattering entropy of farmland is less than 0.5, the co-polarization ratio can mitigate some surface roughness effects. Additionally, when the soil-soluble salt content is incorporated, our model can accurately estimate the soil moisture of salty soil.

Investigation of the influence of packaging cardboard surface topography on the quality of printed products

The article investigates the impact of surface topography of various types of packaging cardboard on the quality of offset printed impressions. It analyzes the morphological structure of coated (GD2) and uncoated (UD3) cardboard, their microstructure, as well as surface roughness parameters such as Ra, peak, and valley areas. The article also provides a comparative analysis of the morphological indicators of unprinted cardboard surfaces and their printed impressions. Recommendations are proposed for selecting packaging materials to ensure optimal print quality.