Surface Roughness Characteristics Research Articles

Comparison study on effect of different lubrication methods on tool wear and surface roughness during end milling of die tool steel

Among all the parameters of machinability evaluation, Surface roughness and chips are one the important parameters, which can influence the functionality and durability of the product machined. Previous research in the domain indicates that machining under dry and minimum quantity lubrication can be a sustainable alternative to the use of conventional flooded coolants. Also, it can minimize the negative impacts of chemical based flooded coolant on Environment, with satisfactory level of performance. This paper compares surface roughness and chips characteristics of Die tool steel material under Dry, Flooded and Micro Lubrication using uncoated carbide inserts. For attainable surface finish, quantification of contribution of input variables such as cutting speed, feed and lubrication mode, statistical method Analysis of Variance (ANOVA) is used. Surface roughness and Flank wear values under Micro-lubrication method significantly reduced compared to dry machining for machining length of 16,800 mm.

Method and Experiment for Quantifying Local Features of Hard Bottom Contours When Driving Intelligent Farm Machinery in Paddy Fields

The hard bottom layer of a paddy field has a great influence on the driving stability and the operation quality and efficiency of intelligent farm machinery. For paddy field machinery, continuous improvements in the accuracy and operation efficiency of unmanned precision operations are needed to realize unmanned rice farming. In the context of unmanned farm machinery operation, the complicated hard bottom layer situation makes it difficult to quantify the local characteristics of paddy fields. In this paper, an unmanned direct rice seeding machine chassis is used to maneuver the operation field and collect the hard bottom layer information simultaneously. This information is used to design a data processing method that automatically calibrates the sensor installation error and performs abnormal value rejection and 3D sample curve denoising of the contour trajectory. A hard bottom layer surface profile evaluation method based on the local sliding surface roughness is also proposed. The local characteristics of the hard bottom layer were quantified, and the results from the test plots showed that the mean value of the local roughness was 0.0065, where 68.27% of the plots were distributed in the variation range of 0.0042~0.0087 and 99.73% were distributed in the variation range of 0~0.0133. Using the test field data, the surface roughness features were verified to describe the variability in representative working conditions, such as the transport, downfield, operation, and trapping of unmanned intelligent farm machinery. When driving intelligent farm machinery, the proposed method for quantifying local features of the hard bottom layer can provide feedback on the local environmental features at any given position of the machinery. The method also provides a reference for the design optimization of unmanned systems, which can help to realize speed adaption and improve the local path tracking control accuracy of smart farming machines.

Analyzing the effect of tool thickness on surface roughness and straightness in CNC parting operation of AA6063

Surface roughness and straightness of AA6063 Aluminium alloy while performing experimental studies during the parting operation is discussed in this paper. The material and its standard dimensions were selected based on easy availability in the market and its application in ship and airplane industries. The selected material has diameter of 25 mm. Parting tool holder and inserts were selected with regards to their compatibility with the CNC machine. High-Speed Steel (HSS) square parting tool holder mounted by uncoated cemented carbide inserts of two different thicknesses, 3 mm and 4 mm were used. Parting operations were carried out on Gedee Weiler Eco Turn ET25 CNC machine using HSS square tool.Process parameters such as Tool thickness (A) (3, 4 mm), Speed (B) (1250, 1500, 1750 rpm), Feed rate (C) (3, 4, 5 mm/min) were varied to determine the results of the experimental study. It was concluded that better surface finish and degree of straightness were obtained at tool thickness of 3 mm, cutting speed of 1750 rpm and feed rate of 4 mm/min. Surface roughness testing was conducted using a Mitutoyo-SJ 210 Stylus-R5 profilometer. Surface straightness testing was conducted on Daisy 564 Cimtrix CMM.The findings indicated that the feed rate, followed by tool thickness and cutting speed, has the greatest influence on the surface roughness (Ra) characteristics of AA6063 material. While comparing the speed and feed in both tool thicknesses, it is observed that as we increase the tool thickness, there is an increase in both surface roughness and in the degree of straightness. The most favorable outcome obtained from the experiment shows that tool thickness 3 mm can be used for better surface finish and flatness.

A numerical study on the impact of lubricant rheology and surface topography on heavily loaded non-conformal contacts

The increasing requirement of high-power density (power throughput/ weight) in modern day machines lead to thin film lubrication condition in various machine components (rolling element bearings, gears, cams, etc,) due to severe loading conditions. Surface roughness features and lubricant rheology plays a vital role in thin film lubrication, and significantly affects the lubrication performance and lifetime of machine components. The present work demonstrates surface topography and lubricant rheology effects on the traction coefficient for heavily loaded non-conformal contacts. The load-sharing concept considering elastic-plastic deformation of asperities, and Carreau shear-thinning rheological model is employed to describe the dry rough contacts and non-Newtonian behavior of lubricant. An influence of surface topography parameters such as roughness, skewness, kurtosis, and pattern ratio on the traction coefficient is discussed. From results, it is found that among different surface topographies, negatively skewed surfaces having isotropic surface pattern exhibit minimum traction coefficient. The load share function and the critical rolling speed are determined for various surface topographies which provides further insights into the surface topography effect on traction coefficient. The findings of present study are noteworthy as they provide a theoretical basis for an assessment of the lubrication performance of heavily loaded non-conformal contacts.

Mathematical Calculation of Material Reliability Using Surface Roughness Feature Based on Plasma Material Interaction Experiment Results

The choice of reactor structural material design must take into account the TOKAMAK fusion reactors' structural reliability. Due to their high levels of heat and energy, fusion reactions have significant deformation effects, which reduce the efficiency of energy production in reactors. Material selection, erosion and damage, heat and stress management, reliability analysis, maintenance, and inspection are crucial elements in determining how reliable fusion reactors are. The focus of this work is on material selection and reliability analysis based on these parameters. The most common wall materials used in fusion reactors are tungsten, beryllium, steel, or graphite. It is advised to utilize aluminum because harmful Beryllium dust limits the study of this element. For this purpose, a target of aluminum samples is established with a plasma of He ions created by glow discharge. The dependability of the samples is determined by calculating the Weibull Distribution and measuring the roughness of the sample surfaces following exposure.

Characterizing canopy complexity of natural and restored intertidal oyster reefs (Crassostrea virginica) with a novel laser‐scanning method

The structural complexity of oyster reef canopy plays a major role in promoting biodiversity, balancing the sediment budget, and modulating hydrodynamics in estuarine systems. Although oyster canopy structure is both spatially and temporally heterogeneous, oyster canopies are generally characterized using simple first‐order quantities, like oyster density, which may lack the ability to sufficiently parameterize reef roughness. In this study, a novel laser‐scan approach was used to map the surface of intact reference and restored reefs (restoration age: 1–4 years) during low tide, when the oyster canopy was fully exposed. Measurements were used to estimate hydrodynamically relevant roughness characteristics over the entire reef surface (>140 m2; 0.50 m resolution), providing estimates of the canopy height (hc), standard deviation (), rugosity index (R), and fractal dimension (D). Average canopy heights ranged from 3.6 to 4.9 cm, with canopy height standard deviations between 1.4 and 2.0 cm. Mean rugosity indices and fractal dimensions were relatively low on the youngest (1 year) restored reef (R = 1.28;D = 2.67), with substantial increases observed for more mature reef canopies (4 years:R = 1.56;D = 2.71). Structural complexity was consistently greater on reef margins than in reef interiors. Increases in complexity were linked to restoration age, with older reefs exhibiting more complex oyster canopies. The highest fractal dimension was observed on the intact reference reef, highlighting the importance of sustained reef growth for maintaining higher‐order structural complexity. Results provide spatially explicit surface roughness characterizations for healthy, intertidal oyster reefs, with applications in both restoration science and natural and nature‐based feature design.

Tool wear and surface roughness characterization during turning of Co-Cr-Mo alloy ASTM F75 with coated carbide tools

Tool wear and surface roughness characterization during turning of Co-Cr-Mo alloy ASTM F75 with coated carbide tools

Morphological classification method and data-driven estimation of the joint roughness coefficient by consideration of two-order asperity

Abstract The roughness of the joint surface plays a significant role in evaluating the shear strength of rock. The waviness (first-order) and unevenness (second-order) of natural joints have different effects on the characterization of joint surface roughness. To accurately quantify the influence of the two-order asperity on the joint roughness coefficient (JRC) prediction of joint surface profile curve, the optimal sampling interval of the asperity was determined through the change of the R p {R}_{{\rm{p}}} value of the joint surface profile curve. The separation of the two-order asperity of 48 joint surface profile curves was completed at the optimal sampling interval, and morphological parameters of the asperity such as i ave {i}_{{\rm{ave}}} , R max {R}_{{\rm{\max }}} , and R p {R}_{{\rm{p}}} were counted from three aspects: asperity angle of the profile curve, asperity degree, and the trace length. Based on the statistical results of the morphological parameters considering the two-order asperity, the new nonlinear prediction models were proposed. The results showed that the curve slope mutation point SI = 2 mm is the optimal separation distance of the two-order asperity of the joint surface profile curve. The refined separation method that considers the waviness and unevenness of morphological parameters can characterize the detailed morphological features of the joint surface in more dimensions. The support vector regression (SVR) and random forest (RF) models that take into account a two-order asperity separated results have higher accuracy than traditional models. The prediction accuracy has improved by 7–8% in SVR model compared with SVR(SO) and RF(SO). The SVR nonlinear model that considering separation of two-orders of joint surface roughness is more suitable for the prediction of JRC.

Machine learning based dual flat-spherical indentation approach for rough metallic surfaces

Instrumented indentation test (IIT) is regarded as one of the non-destructive test methods for mechanical characterization and safety assessment of engineering components. However, indentation test is very sensitive to surface topography i.e surface roughness, requiring specimens with ideally flat and smooth surface for producing reliable and reproducible test results. Recently, a dual flat-spherical indentation (DFSI) technique was proposed to extract material properties directly from rough metallic surface via indentation tests. Integration of DFSI technique with machine learning (ML) approach can facilitate reliable and fast characterization of rough metallic surfaces. Here, ML models including artificial neural network (ANN) and physics-informed artificial neural network (PI-ANN) are established, and then trained by using a database of indentation parameters generated via DFSI simulations. Spherical indentation techniques available in the literature are used to calculate the physics-informed loss in the PI-ANN model. The performances of trained ANN and PI-ANN models are compared, and an optimal ML model with hyperparameters is suggested based on validation study; PI-ANN model with sigmoid activation function shows a better performance than the ANN model and baseline model. The model performances are evaluated by performing DFSI experiments with SM45C and SS304. The applicability of ML based-DFSI method is demonstrated for extracting the mechanical properties from the rough surface of general metals.

Experimental research on the mechanical characteristics of fused deposition modelled ABS, PLA and PETG specimens printed in 3D

In recent years additive manufacturing technologies advanced a lot in fabricating the components. One of the most popular methods for creating components by layer-by-layer material deposition is fused deposition modelling (FDM), often known as additive manufacturing. Focusing on thermoplastic materials 3D printing has huge applications in the aerospace and medical fields, so it is necessary to understand their mechanical characteristics. The Specimen of ABS, PETG, PLA were 3D printed according to ASTM specifications. In this paper, the experiments are carried out to investigate mechanical properties like hardness, surface roughness and visualization of its micro-structure for the following ABS, PETG and PLA 3D printed samples. The effect of results on Vickers hardness, surface roughness and micro-structure characteristics are analyzed and compared with ABS, PETG and PLA in detail. Each and every result in this article provides fabrication guideline for thermoplastics, so getting new functional plastics by printing layer by layer.

Discrete rough surface intensifiers in the thermal decomposition plants: current status and future potential

It is known that roughness affects the drop in hydraulic pressure, increasing the resistance force. The formation of a boundary layer on rough surfaces significantly affects fluid dynamics and the process of heat exchange in convective flows, causing disturbances in the velocity profile and affecting surface resistance, turbulent mixing and heat exchange. Despite the fact that there are a large number of experimental and CFD studies in the field of studying turbulent flow, there is no full-fledged review of this issue. In view of this, it is necessary to systematize studies related to the study of the influence of a rough surface during turbulent fluid flow. In most cases, roughness is quantified only using a single scaling parameter – the equivalent roughness height of a grain of sand, which can be expressed based on statistical parameters. This article presents an overview and generalization of data on the parameters and characteristics of rough surfaces. The correlation method is considered using the standard deviation in the slope of the roughness profile, as well as the effect of the secondary flow on the flow of the coolant in a closed space. The results of this study can be used in the intensification of heat transfer in thermal destruction reactors using intensifiers in the form of discretely rough surfaces. Keywords: discrete-rough surfaces; thermal contact surface;и rough surface; turbulent flow; pyrolysis reactor; thermal destruction; heat exchanger.

RELATIONSHIP BETWEEN WOOD ANATOMICAL FEATURES AND SURFACE ROUGHNESS CHARACTERISTICS

This study aimed to investigate the relationship between surface roughness and anatomical features of wood in 15 different species of boards. Surface roughness was measured parallel and perpendicular to the wood grain using a surface profilometer, and anatomical features such as pore size and distribution were analyzed using microscopic techniques. The results showed that surface roughness perpendicular to the grain direction was consistently higher than that parallel to the grain direction for all wood samples. This difference in roughness was correlated with pore size and density. It shows that the larger pores and lower density lead to higher roughness perpendicular to the grain. The study also found that traditional hand planning methods (push and pull) produced a smooth surface finish, with no statistical differences in roughness.

A New Contact Model of Sphere Asperity in the Fully Plastic Regime Considering Strain Hardening

Abstract Understanding the contact characteristics of rough surfaces is essential to explain engineering phenomenon in interface. In order to improve accuracy of contact model, a novel simplified fully plastic contact model of sphere asperity was proposed considering material properties based on fractal theory. First, based on Von Mises yield criteria, maximum contact pressure factor was derived. Second, relationships taking into consideration strain hardening effects were proposed to describe contact area based on the fully plastic contact area index and contact pressure. Then, the critical interference at inception of fully plastic deformation was derived. Lastly, validations were conducted for different materials. The results show that the present work is remarkably consistent with experimental results and has higher accuracy than other models.

A contribution to debate on surface roughness of clay brick powder generated using varying milling treatments

Recently, the correlation between surface roughness and fineness of materials including pozzolans has been subjected to too much debate in literature. Exploiting the surface roughness of pozzolans has been proven to be significant for cement-based composites. Although research works have been conducted to assess the effects of milling treatments on surface roughness of pozzolans, limited dedicated studies have explored the use of multi-scale characterisation methods for analysing this complex parameter. In this research, an economic and novel technique was employed to characterise the surface roughness of clay brick powder (CBP) subjected to varying milling treatments of various sample masses. The main aim of this research was to investigate the correlations between fineness levels of CBP and surface roughness parameters. Characterisation of CBP generated from ball milling was performed using scanning electron microscopy (SEM) and Gwyddion. There was significant effort employed during the search for significant trends between roughness parameters and grinding clay bricks using different specimen masses, sadly without success. The results of amplitude roughness parameters, fast Fourier transformations, autocorrelation functions and power spectral density functions demonstrated no significant trends for CBP specimens generated under varying specimen masses. Although CBP specimen with highest fineness level seemed to illustrate the lowest roughness characteristics in some cases (i.e. root mean square roughness of 159.182 nm and mean roughness of 115.444 nm), CBP specimen with lowest fineness level did not illustrate the highest surface roughness properties. Through the analyses, it seemed that CBP specimens subjected to different fineness levels could not illustrate significant differences in surface roughness properties and this observation is contrary to some findings in literature. It is believed that the algorithms used for surface roughness characterisation in this research facilitate the understanding of surface roughness properties of CBP specimens subjected to different fineness levels.

Laser Functionalization: An Emerging Modality to Enhance the Osseointegration Potential of Polyetheretherketone as a Dental Implant Material

The unique physical and mechanical attributes of polyetheretherketone (PEEK) have lent significant momentum to the motion that PEEK can be used as a material of choice for dental implants. However, in contrast to titanium or zirconia, PEEK has very limited inherent osteoconductive properties. A wide variety of research has been conducted till date to improve the bioactivity of PEEK surface. Varied methods have been proposed, laser surface treatment of PEEK being one of the promising techniques. Data collection was limited to the last 10 years from 2012 to 2021. Eleven articles were found suitable for this review found in the databases of PubMed and Google Scholar. Considerable alterations have been observed in surface roughness and wettability characteristics of PEEK after laser surface treatment, which improved the osseointegration property of PEEK to be utilized as a dental implant material. The current paper is aimed at reviewing different types of laser applications to the PEEK surfaces and its effect on bone-to-PEEK implant contact.

Analysis of surface roughness on aluminium alloy – Graphene composites

Nowadays, in the prevailing competitive environment aluminium alloy based composites are playing a vital role in developing materials with tailored properties suitable for aerospace and automotive application. In this research work, composites are developed through stir and squeeze casting techniques using aluminium alloy 7050 reinforced with graphene. The critical parameters like pouring temperature, rotation speed of stirrer and reinforcement content (wt % of Graphene) with different levels were considered for the experimental work. Surface roughness characterization studies were performed on the composite specimen developed through both the processes using different levels of experimentation. Analysis of Variance (ANOVA) was performed to identify the significance of the influencing factors on the surface roughness of the samples fabricated through the two different processes.

DETERMINATION OF RELIABLE AREA SIZES FOR 3D ROUGHNESS MEASUREMENT

Surface roughness characterization plays an important role in the qualification of machined surfaces. As a result of the development of high resolution 3D scanning techniques, researchers and technologists have more possibilities to analyze surface topography in a more detailed way. The purpose of this study is determining the minimal measurement area size of surfaces hard machined by single-point and abrasive tools. Some important height parameters were analyzed: Sa, Sq, Sp, Sv, Ssk and Sku. It was found that the minimum area sizes vary for the different roughness parameters, however, in several cases minimization is possible, depending on the purpose of the surface analytics.

Thermo-hydrodynamic Analysis of Misaligned Journal Bearing Considering Surface Roughness and Non-Newtonian Effects

This paper presents a numerical simulation for the combined effect of surface roughness and non-Newtonian behavior of the lubricant on the performance of misaligned journal bearing. The modified Reynolds equation to include the effect of non-Newtonian lubricant and bearing surface roughness has been formulated. The model accounts for the lubricant viscosity dependence on temperature and shear rate. In order to make a complete thermo-hydrodynamic analysis (THD) of rough surface misaligned journal bearing lubricated with non-Newtonian lubricant, the modified Reynolds equation coupled with the energy, heat conduction equations, the equation related the viscosity and temperature with appropriate boundary conditions have been solved simultaneously. The performance characteristics of the bearing were presented with different roughness parameter for the pressure, temperature, load carrying capacity, misalignment moment and friction force. The computer program prepared to solve the governing equations of the problem has been verified by comparing the results obtained through this work with that published by different workers. It has been foundthat the results are in a good agreement .The results obtained in the present work showed that the surface roughness characteristics of opposing surfaces and its orientation play an important role in affecting the performance parameters of the bearing. It has been shown that the load in rough aligned journal bearing is higher than that in rough misaligned journal bearing for all surface roughness patterns (γ). An increase in load has been calculated and found to be 29.5% for the bearing with moving roughness while it becomes32% for the bearing with stationary roughness.

Wear behaviour of lithography ceramic manufactured dental zirconia

ObjectiveThe study aims to evaluate the wear surface using 3D surface roughness and other material characterization of zirconia fabricated using photopolymerization based Lithography-based Ceramic Manufacturing (LCM).MethodLCM technology was used to fabricate zirconia specimens of size 10 × 10 × 2mm3. Scanning Electron Microscope, 3D–profilometer, X-ray Diffraction, and hardness test characterized the samples before and after wear and Coefficient of friction (COF) was monitored.ResultThe COF was around 0.7 and did not differ much between the horizontally and vertically printed specimens. However, the surface roughness after wear for horizontally printed specimen was 0.567 ± 0.139 μm, while that for vertically printed specimen was 0.379 ± 0.080 μm. The reduced valley depth and the dale void volume were low for the vertically printed zirconia specimen, indicating lesser voids and low fluid retention. In addition, it was observed that the hardness value of the vertically printed sample was better. The scanning electron microscopic images and 3D surface profiles of the zirconia specimens depicted the surface topography and revealed the wear track.ConclusionThe study shows that zirconia fabricated using LCM technology possesses surface roughness of about 0.5 μm with no machining scars that are usually associated with CAD/CAM dentistry and also indicating agreement with clinically acceptable values for minimal surface roughness of dental restorations. Dental restorations using LCM fabricated zirconia redues the requirement of post-processing work flow that is part of CAD/CAM dentistry.

Trans-scale rough surface contact model based on molecular dynamics method: Simulation, modeling and experimental verification

Contact interfaces widely exist in mechanical structures from macroscopic to microscopic scales and play an important role in understanding the properties and dynamics of the structures. To obtain the contact behavior, it is essential to include the plastic deformation characteristics on rough surfaces (caused by dislocation in asperity), while they are not properly considered in the traditional macroscopic models. This work presents a trans-scale rough surface contact model with the combination of the macroscopic model and the microscopic deformation mechanism by MD simulation. (I) Based on the molecular dynamics (MD) simulation results of a single-asperity normal contact, the relationship between the critical interference and the asperity size is fitted. The results show that the critical interference of the asperity is affected by its size, especially at the microscopic scale. Large asperity produces small critical interference. (II) A trans-scale rough surface contact model was established based on the fitted curves, which considered the joint distribution of asperity radius and height and the asperity size effect. (III) The influence of parameters was analyzed, and the predicted results of the proposed model and the traditional models were compared with the experimental results and MD simulation results. The results show that compared with other traditional models, the proposed trans-scale model has better performance in describing the normal contact characteristics of rough surfaces at both macroscopic and microscopic scales, showing the ability of full-scale description.