Surface Roughness Research Articles

Assessing the combined effects of chemical and mechanical parameters on silar-grown nanostructured ZnO thin films

In the literature, a comprehensive assessment of the combined impacts of chemical and mechanical parameters on the properties of thin films grown by SILAR is missing. In this work, ZnO film formation is investigated under variable precursor concentration, pH, withdrawal speed and number of cycles. Interestingly, the produced ZnO films displayed remarkable aspect ratio and morphological variability, ranging from the commonly obtained nanograins shape towards hexagonal nanorods, flower- like rods and nanoneedles, which to our knowledge have not yet been achieved by using single step SILAR process. More particularly, low concentration and intermediate pH and withdrawal rates were favorable for nanorods formation. In addition, increasing the withdrawal speed from 26 to 30 cm·min-1 resulted in a thinner film with improved rod uniformity and reduced crystallite size. This is the first study on the impact of substrate withdrawal speed on SILAR films. Among all studied parameters, the number of cycles was particularly useful for tuning film thickness, while preserving its target shape. In addition, the films grown under a higher number of cycles showed improved film crystallinity and rod orientation with reduced dislocation density, microstrain and bandgap energy. In our conditions, the most suitable combination of parameters required for exhibiting optimized nanorod-shaped coating are: a concentration of 0.07 M, pH of 10.5, speed of 30 cm·min-1 and 40 cycles. In this case, XRD, XPS, Raman and FTIR spectra displayed typical features of hexagonal Wurtzite structure of ZnO with no impurities within the film surface, whereas AFM measured a thickness of 1.4 μm with 243 nm surface roughness.

EDC of graphite using powder metallurgical green compact W-Cu tools

ABSTRACT This paper investigates the Electro Discharge Coating method for modifying graphite surfaces by powder metallurgical green compact tool composed of 75% Tungsten+ 25% Copper by weight. Key input parameters include compact load (CL), peak current (Ip) and pulse on-time (Ton), while the output responses are tool wear rate (TWR), material transfer rate (MTR) and surface roughness (Ra). The coated surfaces undergo detailed characterization and analysis to assess their properties. A higher MTR of 52.25 mg/min, a TWR of 285.10 mg/min, a Ra of 6.10 µm and a layer thickness of 173.90 μm are measured at a CL of 10 ton, a Ip of 4 A and a Ton of 400 µs, whereas a lower MTR of 6.02 mg/min, a TWR of 48.02 mg/min, a Ra of 3.40 µm and a layer thickness of 35.72 μm are measured at CL of 20 ton, Ip of 2A and Ton of 100 µs.

Effects of Polyethylene Glycol and Chloride Ion on Copper Electroplating at High Current Density

To determine the effect of Polyethylene Glycol(PEG) and Chloride ions(Cl-) as additives during electroplating, this study used interaction plots of various characteristics of the electroplated Cu foils for analyses. Crystals of about 2 µm in size were observed on the surface of Cu electroplated in the electrolyte without PEG. When 30-100 ppm PEG was added, the crystal size and surface roughness decreased in relation to the amount of PEG. However, there were lots of dented areas, which became fewer as Chloride ions were increased from 20 ppm to 40 ppm. When 300 ppm PEG was added, the dented areas were not observed. Nevertheless, the surface morphology was very irregular and rough. In the group with 30-100 ppm PEG added, the resistivity decreased due to the increase in grain size. Moreover, the tendency of crystals to grow preferentially in the direction of the (111) plane led to an increased resistance to EM(electro-migration). When 40 ppm of chloride ions and 100 ppm of PEG were added, the yield strength increased by 22.4%, the tensile strength increased by 28.7%, and the elongation increased by 293.5% compared to the group without additives. This study showed that a combination of appropriate additives and amounts was required to form copper foils with low surface roughness, excellent electrical properties, and EM resistance and low corrosion rate. Therefore, with 100 ppm added PEG, it is necessary to add 20 ppm of chloride ions to ensure a low corrosion rate and 40 ppm of chloride ions for high mechanical properties.

Surface characteristics of resin composite cores and bond strength to CAD/CAM resin matrix glass-ceramic restorations after different treatment protocols.

The purpose of this study was to evaluate the impact of various mechanical surface treatments on thesurface roughness and microtensile bond strength (µTBS) of aged composite resin cores bonded to CAD/CAM restorations. Composite resin specimens (Filtek Z350 XT, 3M-ESPE/Solventum) were thermally aged and subsequently divided into four groups (n = 36) according to surface treatments: UI-cleaning with ultrasonic diamond tip; AO-sandblasting with 50µm Al2O3; DB-cleaning with diamond burs; and CG-positive control group, without aging or surface treatment. Surface roughness was assessed using a profilometer and interferometer, with measurements taken on both sides of each specimen (n = 12). The surface characteristics were further analyzed through scanning electron microscopy (SEM) (n = 12). In addition, PMMA blocks were temporarily cemented (n = 12) onto the resin blocks, and after surface treatments, resin matrix glass-ceramic blocks were adhesively luted with dual-cure resin cement (RelyX Ultimate, 3&nbsp;M-ESPE/ Solventum, St. Paul, MN, USA) to the resin composite substrates. The CG specimens were adhesively luted to the indirect restorations without temporary restorations or surface treatment. After luting, the specimens were sectioned and tested for µTBS. The results (p = 0.05) from the profilometry and interferometry analyses indicated the highest surface roughness values for the DB group, followed by AO, UI, and CG. SEM analysis revealed marked morphological differences among the groups. Regarding µTBS, the GC specimens (25.78 ± 5.70MPa) and UI specimens (25.56 ± 11.36MPa) exhibited statisticallysimilar values, which were superior to those of the AO (12.25 ± 4.34MPa) and DB (13.16 ± 5.59MPa) groups (p < 0.001), which showed comparable results. In conclusion, the use of ultrasonic diamond tips resulted in the most favorable outcomes in terms of cleaning effectiveness, surface roughness, and bond strength among the surface treatments analyzed for resin composite cores.

Hydride-Induced Reconstruction of Pd Electrode Surfaces: A Combined Computational and Experimental Study.

Designing electrocatalysts with optimal activity and selectivity relies on a thorough understanding of the surface structure under reaction conditions. In this study, experimental and computational approaches are combined to elucidate reconstruction processes on low-index Pd surfaces during H-insertion following proton electroreduction. While electrochemical scanning tunneling microscopy clearly reveals pronounced surface roughening and morphological changes on Pd(111), Pd(110), and Pd(100) surfaces during cyclic voltammetry, a complementary analysis using inductively coupled plasma mass spectrometry excludes Pd dissolution as the primary cause of the observed restructuring. Large-scale molecular dynamics simulations further show that these surface alterations are related to the creation and propagation of structural defects as well as phase transformations that take place during hydride formation.

Surface Roughening Behavior and Mechanism in Aluminum Alloy Under Tensile Deformation

Surface roughening (SR) has been found to occur in solid solution 2219 aluminum alloy under tensile deformation, which will deteriorate its surface quality. To make a precise study of the surface roughening (SR) behavior and mechanism, the surface morphology of annealed and solid solution 2219 aluminum alloy was compared and crystal plasticity finite element (CPFE) simulation was carried out in this study. Thereinto, representative volume element (RVE) models of polycrystals were established according to the initial grain morphology measured by electron backscatter diffraction (EBSD). The results show that the surface roughening degree of the solid solution specimen is worse than that of annealed specimen after uniaxial tension deformation. In comparison with the annealed specimen, the grains show a larger size after solid solution treatment, thus resulting in the coarse surface to a certain extent. Moreover, texture type and density also have a significant influence on surface roughness. The rotation of grains with an S and Copper orientation intensifies the surface roughening during tensile deformation. The deformation difficulty of Goss texture in the normal direction (ND) and tangential direction (TD) varies, thus contributing to the different surface morphology. The research results will provide guidance for the improvement of the surface quality of high-strength aluminum alloy aerospace components.

Multi-Objective Optimization of the Surface Grinding Process for Heat-Treated Steel

This paper effectively integrates Taguchi, Response Surface Methodology (RSM), and Genetic Algorithm (GA) approaches for both single and multi-objective optimization, delivering low-cost, high-effectiveness solutions for grinding. It examines the effects of three factors—depth of cut in coarse grinding, depth of cut in fine grinding, and the number of spark-outs—on three objectives: surface roughness, grinding time, and the deviation between the desired and actual grinding depth for SKD61 steel. Through in-depth analysis, the paper describes the impact of these factors and their interactions with the responses. It also proposes the optimal parameter setup for each objective. The optimal grinding time is achieved at 950 seconds with a coarse grinding depth of 0.007 mm, fine grinding depth of 0.004 mm, and zero spark-out. The minimal deviation and surface roughness were obtained at 0 mm and 0.144 µm, respectively, using the optimal setup of a coarse grinding depth of 0.004 mm, fine grinding depth of 0.001 mm, and 10 spark-outs. By applying GA, the paper provides a Pareto solution set, offering multiple combinations of optimal factors for minimizing grinding time, deviation, and surface roughness. These solutions serve as useful references for users seeking the best trade-offs in multi-objective scenarios. This paper contributes to improving customer satisfaction by enhancing the quality and efficiency of the machining process while reducing production costs for grinding machines. Its methodology can also be applied to other optimization fields.

Optimization of machining parameters while turning AISI316 stainless steel using response surface methodology

The chromium-nickel alloy known as AISI 316 Stainless Steel is extensively used in various industries, such as the chemical industry, nuclear power plants, and medical devices, due to its exceptional mechanical properties and corrosion resistance. Compared to other stainless steels, AISI 316 resists corrosion from air and other corrosive conditions better. Determining the optimal selection of machining parameters is still a challenge for many researchers. The Box Behnken technique (L12 array) is used in this work to design the experiment set. Response surface methodology (RSM) is used to examine how the cutting velocity (100, 150, and 200 m/min), feed (0.10, 0.15, and 0.20 mm/rev), and depth of cut (02, 0.4, and 0.6 mm) affect the cutting force (Fc), surface roughness (SR), power consumption (Pw), and tool life (T). The ANOVA investigation shows that cutting force and surface roughness increase linearly with an increase in feed. Similarly, power consumption and tool life also increase linearly with an increase in cutting velocity. The best combination for the lowest Fc, SR, and Pw and the maximum T is cutting velocity at 122.37 mm/min, feed at 0.13176 mm/rev, and cut depth at 0.213337 mm. For cutting force, surface roughness, power consumption, and tool life, the actual and predicted values are (124.31, 129.45), (0.55, 0.57), (1.131, 1.154), and (2112, 2225), respectively. For the lowest feasible values of Fc, SR, Pw, and maximum T, the optimal settings are a cutting speed of 122.37 mm/min, feed of 0.13176 mm/rev, and depth of cut of 0.213337 mm.

Stereolithography 3D printing gyroid triply periodic minimal surface vitrified bond diamond grinding wheel

The pores of vitrified bond diamond grinding wheel play a key role in the grinding process. However, uneven pore distribution and low porosity affect the grinding performance of the wheel significantly. Stereolithography based additive manufacturing provides an effective method to fabricate vitrified bond diamond grinding wheels with a uniform distribution and an interconnected pore structure. The key to high-performance grinding wheel via stereolithography 3D printing lies in the preparation of the slurry with high solid loading, low viscosity and uniform stability. In this study, the dispersion and stability of vitrified bond and diamond slurries were investigated systematically. The effects of resin monomers, surface modifiers, and solid loading on the dispersion, rheological behavior and stability of slurries were studied in detail. Finally, an optimal vitrified bond and diamond slurry for stereolithography based additive manufacturing was obtained, and complex-shaped gyroid triply periodic minimal surface grinding wheel were fabricated. By grinding the SiC ceramics, the material removal rate, grinding temperature, and surface roughness were compared to those achieved using a conventional solid structure grinding wheel. The results show that the gyroid porous grinding wheel can achieve better surface roughness and lower the grinding temperature.

Land coverage prediction using convolutional neural network for enhanced wind loading estimation

PurposeThe wind loading on a building is likely to deviate further from the known wind loading due to the complexity of the real-world land coverage. To address this issue, research is needed in two separate areas. First, wind tunnel testing needs to be conducted for more complex terrains. Second, research is needed to classify real-world land coverage with high accuracy, specifically for wind engineering applications. This paper deals with this second area of research. The machine learning-based land cover prediction is a promising technique because it can remove subjectivity in human interpretation of upwind terrain.Design/methodology/approachThis paper presents a new deep neural network for land coverage prediction that can distinguish low- and mid-rise buildings in the built environment to enhance the estimation of surface roughness necessary in wind engineering. For the dataset, Landsat 8 satellite images were used. A patch-based convolutional neural network was employed and improved. The network predicted the land coverage at the center of the patch. Two different label schemes were used where the proposed network either achieved better accuracy than the conventional model or recognized additional building types while maintaining a similar level of accuracy.FindingsCompared to the validation accuracy of 78% in a previous study, the proposed method achieved the validation accuracy of 90% thanks to the improvements made in this study as well as the consolidation of labels with similar surface roughness. When additional building categories were added, the validation decreased to 80%, which is comparable to the previous study but is now able to predict different building types.Originality/valueThe improvement of the proposed method will depend on the site characteristics. For the sites tested in this paper, the error reduction in wind speed and pressure was up to about 55%. In addition to more accurate wind speed and pressure, better identification of buildings will benefit wind engineering research, as different building types cause different downwind effects. An example application would be automated recognition of areas that have a certain distance from the target building type to identify downwind areas affected by high winds.

Tillandsia-Inspired Asymmetric Covalent Organic Framework Membranes for Unidirectional Low-Friction Water Collection.

Friction plays a pivotal role in many phenomena of physical chemistry and has long been in the focus of research thereof. As a crucial parameter, frictions in membranes' inner and/or outer surfacecan be minimized toreducesolvent inlet pressure and enlarge inner pore fluid flux, ideally reachingnear frictionless transport of water at nanoscale. Inspired by the leaf structure of Tillandsia, a porous membrane with a rough surface and a hydrophilic inlet together with hydrophobic pore channels was designed and fabricated, based on covalent organic frameworks (COFs). Combined with COFs' inherent highly oriented pore structures, theas-madeasymmetric membranes through chemical etching can minimize the solvent critical intrusion pressure andenableinner pore low friction water transport. Ultimately, obtained COF membranes succeeded intrappingfog from air and achieved a water harvesting rate(WHR) of 1570 mg cm-2h-1, together with small molecular pollutants filtratedoffin the meantime. Intriguingly, the synthesized asymmetric COF membranes illustrated unidirectional low friction water collecting and transporting features, the successful imitation of T. macdougallii. This work presentsapractical strategy to construct functional porous membranes for low friction water collection and transport,and created a model paradigm todesign fluid transporting pore channels.

Tillandsia‐Inspired Asymmetric Covalent Organic Framework Membranes for Unidirectional Low‐Friction Water Collection

Friction plays a pivotal role in many phenomena of physical chemistry and has long been in the focus of research thereof. As a crucial parameter, frictions in membranes’ inner and/or outer surface can be minimized to reduce solvent inlet pressure and enlarge inner pore fluid flux, ideally reaching near frictionless transport of water at nanoscale. Inspired by the leaf structure of Tillandsia, a porous membrane with a rough surface and a hydrophilic inlet together with hydrophobic pore channels was designed and fabricated, based on covalent organic frameworks (COFs). Combined with COFs’ inherent highly oriented pore structures, the as‐made asymmetric membranes through chemical etching can minimize the solvent critical intrusion pressure and enable inner pore low friction water transport. Ultimately, obtained COF membranes succeeded in trapping fog from air and achieved a water harvesting rate (WHR) of 1570 mg cm‐2 h‐1, together with small molecular pollutants filtrated off in the meantime. Intriguingly, the synthesized asymmetric COF membranes illustrated unidirectional low friction water collecting and transporting features, the successful imitation of T. macdougallii. This work presents a practical strategy to construct functional porous membranes for low friction water collection and transport, and created a model paradigm to design fluid transporting pore channels.

A novel ultrasonic shot peening method for surface enhancement of fastener holes

Hole structures represent discontinuities in mechanical parts, and their inner walls need to be surface strengthened to enhance the service performance. In this study, a novel ultrasonic shot peening (USP) method, which is equipped with a wave-shaped horn and can be inserted into holes is developed to strengthen the fastener holes. Firstly, the axis uniformity of static and motional USP systems is compared in 304SS holes. After treated by static USP, the peening intensity along the hole axis is consistent with the wavy surface of the horn. The impact velocity and impact number of the balls driven by the trough of the horn are approximately four times and three times higher, respectively, compared to those driven by the peak structure. Thus the regions treated by the trough of the horn exhibit greater surface roughness (Ra = 0.97 μm), higher hardness (510 HV) and a deeper deformed layer (94.3 μm). While the motional system effectively improves the axis uniformity of the holes by diminishing the concentration of the stronger and weaker shot peening areas. For GH4169 holes treated by motional USP, a cold work layer with depths of 100–150 μm is formed; a plastic deformed layer exceeding 50 μm is observed and a residual compressive stress layer exceeding 200 μm is introduced. These results are consistent with those of plate or cylindrical samples treaded by USP. Moreover, the differences between USP and other techniques are subsequently discussed.

Behavior of PGS/apatite foam scaffolds during incubation in SBF, PBS, Ringer's solution, artificial saliva, and distilled water.

Poly(glycerol sebacate) is a polymeric material with potential biomedical application in the field of tissue engineering. In order to act as a biodegradable scaffold, its incubation study is vital to simulate its behavior. This study explores the degradation of porous poly(glycerol sebacate)/hydroxyapatite scaffolds subjected to incubation in various physiological solutions. The research involved monitoring pH and conductivity values over a 14-day period, as well as analyzing the swelling capacity and mass alterations of the scaffolds. In simulated body fluid (SBF) and phosphate-buffered saline (PBS), the pH levels remained relatively stable, whereas Ringer's solution caused a pH decrease. Conversely, artificial saliva demonstrated an increase in pH, and distilled water caused a slight decrease. The conductivity values remained stable in SBF and Ringer's solution, slightly decreased in PBS, increased in artificial saliva, and significantly increased in distilled water. The swelling capacity of the scaffolds varied depending on the solution used, with the lowest equilibrium swelling observed in SBF and PBS. The effect of the presence of ceramics on this parameter was also observed. The mass changes of the scaffolds indicated deposition of particles or salts from the incubation solutions, and subsequent rinsing in distilled water led to a decrease in mass. Scanning electron microscopy (SEM) imaging and elemental analysis confirmed the presence of crystallized salts on the scaffold surfaces after incubation in SBF. Surface roughness measurements revealed changes in roughness depending on the solution, with deposition of additional layers in SBF and degradation in artificial saliva. In summary, the scaffolds exhibited biodegradation in physiological solutions, with variations in pH, conductivity, swelling capacity, mass changes, and surface morphology depending on the specific solution and scaffold composition.

Surface Characterization of Bone-Level and Tissue-Level PEEK and Titanium Dental Implant Scan Bodies After Repeated Autoclave Sterilization Cycles

Background: Sterilization is required for any biomedical device intended to be used in contact with the human body. Several studies have reported alterations in the bulk and surface properties of such devices after repeated sterilization cycles. These surface modifications may influence other clinical parameters. Therefore, the aim of this study was to investigate the surface and chemical properties of implant scan bodies (SBs) after consecutive autoclave sterilization procedures. Methods: The objective was to analyze the scan bodies using Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS) for chemical analysis and an optical profilometer to analyze the surface roughness. Results: FTIR spectra depicted the appearance of peak at 1741 and 1100 cm−1 due to the diphenyl ether band disappearance. The XPS spectra showed alterations in the elemental composition after autoclaving and roughness were significantly reduced in PEEK BL and TL SBs. Conclusions: These results indicated that some surface modifications were induced by repeated sterilization cycles.

ANALYZING THE EFFECTS OF MANUFACTURING PARAMETERS MODIFICATION ON FINAL SURFACE ROUGHNESS IN SELECTIVE LASER MELTING PARTS

Selective Laser Melting (SLM) is an additive manufacturing technique widely used today for producing metal components. This method enables the fabrication of geometrically complex parts while reducing costs and production time compared to traditional manufacturing techniques. However, a notable drawback of SLM is its tendency to produce high surface roughness and superficial defects such as balling, porosity, debris, and waviness. This study evaluates the effects of modifying two manufacturing parameters—scanning speed and laser power—on the final surface roughness. To achieve this, cylindrical specimens were fabricated using various combinations of these parameters, and the resulting surface roughness metrics (Sa, Sq, Ssk, Sku, Sdr, among others) were measured using an optical 3D surface roughness measurement instrument. A Taguchi L8 design was applied to analyse the influence of the manufacturing parameters on the measured roughness characteristics. This study investigates the influence of laser power and scanning speed on surfaces manufactured through Selective Laser Melting (SLM) and their effects on the previously described roughness parameters. The authors observed that the manufacturing parameters have varying impacts on the final surface roughness of components produced via SLM. Due to the inherent characteristics of the process, a specific combination of parameters that reduces roughness within a specimen's layer may increase roughness at the layer boundaries. These findings underscore the complex relationship between manufacturing parameters and surface roughness in SLM-produced parts, emphasizing the need for strategies, such as surface finishing post-treatments, to achieve the desired surface quality.

Phase transformation and texture evolution during micro-incremental forming of ultra-thin SS316 sheets

Size effects present significant challenges in micro-scale manufacturing, compounded by the complexities of tooling and fixture design. However, Micro-incremental Sheet Forming (µ-ISF) has emerged as an innovative die-less forming technique for producing miniature products, effectively addressing some of these challenges. This study focuses on the formability analysis of annealed SS316 foils of various thicknesses. Trapezoids with different aspect ratios were produced using three different tool diameters (Td). It was observed that an increase in Td led to a decrease in both surface roughness and wall angle limit. This reduction in formability was thoroughly investigated through microstructural analysis, revealing that deformation-induced phase transformation (DIPT) is one of the key factors contributing to the decreased formability of SS316 foils.

Preparation and Corrosion Resistance of Superhydrophobic Composite Coatings on Shot-Peened AA 7075-T6 Aluminum Alloy

In order to further improve the corrosion resistance of 7075-T6 aluminum alloy after shot peening, corrosion-resistant superhydrophobic coatings (EP-HDTMS@SiO2) containing epoxy resin (EP), cetyltrimethoxysilane (HDTMS), and nano-silica (SiO2) were prepared by a simple spraying method on the surface of shot-peened AA 7075-T6 aluminum alloy. The effects of different EP/SiO2 mass ratios on the micro-morphology, surface wettability, and corrosion resistance of the superhydrophobic composite coatings were analyzed. Due to the combination of microstructure and the modification of low surface energy organics, the contact angle of EP-HDTMS@SiO2 coatings reached the superhydrophobic level (152.6°). The electrochemical tests showed that the corrosion current densities (Icorr) of the EP-HDTMS@SiO2 composite coatings were both significantly lower than those of the EP-HDTMS coatings and matrix aluminum alloys. The addition of SiO2 nanoparticles could improve the hydrophobicity and corrosion resistance of epoxy-based composite coatings. Due to the increase in surface roughness and epoxy resin, the shot-peened AA 7075-T6 alloy coating had high adhesion after the peel test. The prepared coatings also showed excellent corrosion resistance in the neutral salt spray test. This study provides a simple method for preparing stable superhydrophobic coatings on metal surfaces, which is expected to expand the application of 7075 aluminum alloy in harsh environments.

Novel CeO2@MOF and its derived abrasives for rapid chemical mechanical polishing

In recent years, with the reduction of the feature size of integrated circuits and the improvement of chip integration, the polishing performance of CeO2 abrasives is required to be of higher quality. The factors that influence the polishing properties of CeO2 abrasives typically include morphology, dispersion, crystallinity, and chemical activity. In this study, spherical CeO2@MOF composite was synthesized utilizing a simple one-step method, and CeO2 particles with identical morphology were synthesized using this material as the precursor. Compared with CeO2 nanoparticles, CeO2@MOF composites exhibited lower crystallinity and dispersibility, but higher concentrations of Ce3+ and oxygen vacancy, indicating higher chemical activity. When the two abrasives were used in CMP experiments on silicon oxide wafers, the material removal rate (MRR) of CeO2@MOF was 36.35 ± 3.9 nm/min, which is 50.2 % higher than that of CeO2 nanoparticles, and the surface roughness was as low as 0.141 nm, which was 22 % lower than that of CeO2 nanoparticles. According to the results of CMP, compared with the enhancement of physical properties such as crystallinity and dispersion, the improvement of chemical properties can enhance the polishing performance of cerium-based abrasives. This study presents a novel approach for the synthesis and application of cerium oxide abrasives.

Multi-Objective Optimization of Finishing Milling of C45 Steel using Factorial Design

This study presents an innovative approach to optimizing the milling process of C45 steel using a factorial design of experiments. The impact of key technological parameters, including cutting speed (Vc), feed per tooth (fz), depth of cut (ap), and lubrication conditions (dry and flood), on surface roughness (Ra) and Material Removal Rate (MRR) was thoroughly analyzed. Through the application of Analysis of Variance (ANOVA), significant factors and their interactions were identified, with fz and lubrication conditions showing the most substantial influence on Ra. The interaction between fz and lubrication condition was particularly notable, highlighting the importance of these parameters in achieving optimal surface quality. Multi-objective optimization was conducted using the desirability function method to balance the objectives of minimizing Ra and maximizing MRR. The optimal Vc and fz conditions under flood lubrication were found 200 m/min and 0.3 mm/tooth, respectively, achieving a desirability index of 0.801. Under dry lubrication, the optimal conditions were 200 m/min and 0.3 mm/tooth, respectively, with a desirability index of 0.803. These results demonstrate that both lubrication conditions can be effectively optimized to enhance machining performance. The findings provide a comprehensive framework for improving the milling process of C45 steel, contributing valuable insights into the effects of cutting parameters and lubrication conditions on surface quality and MRR.