Roughness Parameters Rz Research Articles

Analyze the effects of CNC machining parameters on the surface roughness (Rz) of Anatolian chestnut

The effect of processing parameters on the surface roughness parameter Rz (mean peak-to-valley height) in CNC machining of Anatolian chestnut (Castenia sativa Mill.) wood species used in the woodworking and furniture industry was investigated. The machining conditions were determined to obtain the lowest Rz value. The experi-ments were carried out at the speeds of 8000, 12000, and 16000 rpm and the feed rates of 1000, 1500, and 2000 mm/min with 3 and 4 machining layers by using two different cutters with a diameter of 8 mm. Rz measurements were made on the obtained surfaces using the needle scanning method according to TS EN ISO 21920-2 (2021). In the measurements perpendicular to the fibers, the lowest Rz values were obtained with cutter type 2 (the cutter of the three cutting edge straight end mill), at 16000 rpm speed, 1000/2000 mm/min feed rate, and four machining layers. In the measurements made parallel to the fibers, the lowest Rz values were obtained at the cutter type 2 (the cutter of the three cutting edge straight end mill), at the speed of 16000 rpm and the feed rate of 1000/2000 mm/min and 4th step-down. A smooth surface (lower Rz value) was obtained with fourth cuts (step down, cut layer) instead of third cuts.

Improving the surface quality of AlMgSi1 alloy with the selection of the appropriate vibration grinding stones

The number and variety of paints and coating systems in the automotive industry have increased in recent years. However, the basic requirement for the quality of the paints still depends on the surfaces on which they are applied. This applies not only to the large body parts but also to all components that are integrated.There are many surface treatment processes and techniques that are used as an additional process step, such as pickling for a chemical surface treatment or blasting for a mechanical surface treatment.The present work investigates a method for optimizing the surface before painting, using the membrane cup of the ultrasonic sensor as an example for AlMgSi1 alloy, without implementing additional process steps.First, all process steps influencing the surface quality for the production of a membrane cup were considered for optimization. Then, based on a backward process chain analysis, vibratory grinding for deburring of the membrane cup was determined as the process step to be optimized. For the optimization of the vibratory grinding, experiments with two different grindstones were performed. For the characterization of the surface quality, the roughness parameters Rz and Ra were measured with a confocal laser scanning microscope and analyzed in order to determine the optimal process conditions.The experiments showed that the surface roughness can be significantly improved using dedicated process parameters and taking into account the geometry of the vibratory grinding stones. Moreover, different surface qualities can be achieved at different areas on the workpiece, this new approach provides a solution for surface optimization in various areas of the workpiece without additional process steps and costs.

Formation Model for Acoustic Characteristics of Solid Media with Ordered Fracturing

Introduction. The development of new structural materials and improvement of existing technologies for the production of new products on their basis lead to the emergence of new types of medium discontinuities. Therefore, the development of new models of discontinuities that take the previously ignored parameters into account seems to be relevant for the purposes of nondestructive testing and structural measurements. This concerns, e.g., the roughness of adjacent surfaces of microcrack ordered sets.Aim. Theoretical substantiation for the processes of elastic waves propagation through an elastic medium containing an ordered lattice of microcracks with boundary conditions in the linear slip approximation, modified by taking into account the parameters of micro-convexities of microcrack rough boundaries. Database formation for experimental studies aimed at determining the physical and mechanical characteristics of structural materials.Materials and methods. The acoustic characteristics of materials were determined based on the derivation and solutions of dispersion equations describing the formation and propagation of effective longitudinal, transverse, and Rayleigh surface elastic waves in elastic media with ordered cracking. Their values were also used to determine the effective speed of Rayleigh surface waves.Results. The conducted simulation of elastic wave formation processes showed that an increase in the concentration of microcracks leads to a decrease in the phase velocities of effective longitudinal, transverse, and surface waves, as well as to an increase in the attenuation coefficients at given ultrasound frequencies and material parameters.Conclusion. The radius of the microsphere that replaces the surface micro-convexity and the roughness parameter Rz have a significant impact on the formation of physical and mechanical characteristics of materials, which are determined by the results of ultrasonic measurements. The developed model can be recommended as a basis for interpreting the results of ultrasonic measurements.

Surface quality and dry sliding wear behavior of AZ61Mg alloy using Abbott firestone technique

Currently, magnesium alloys are widely utilized in diverse sectors due to their unique properties. However, the AZ61Mg alloy, a commonly used magnesium alloy, is known to have poor wear resistance, which limits its applications. To address this issue, researchers have investigated various surface treatment techniques, including the Abbott Firestone method, to improve the wear resistance of this alloy. This study employs response surface methodology (RSM) to examine the effects of pressure and velocity on wear behavior and Abbott Firestone zones of AZ61Mg alloy. Three pressure (0.01, 0.015, and 0.02 MPa) and velocity (0.57, 0.76, and 0.95 m/s) levels are used to conduct dry sliding wear tests at room temperature using a pin-on-disc method with an experimental design technique (EDT). Analysis of variance ANOVA is employed to identify the relationship between the input parameters (pressure and velocity) and the responses (wear rate, Surface Roughness Parameter Rz, and Abbott Firestone zones) of the AZ61Mg alloy. The optimized models for wear rate and Abbott Firestone zones yielded accurate estimations, which can enhance cost-effectiveness and efficiency. The findings indicate that pressure and velocity significantly affect the wear behavior of the AZ61Mg alloy.

The influence of the cooling conditions and inclination of surfaces obtained by 3D printing on the roughness parameters

A characteristic of the evolution of manufacturing processes in recent years is the expansion of technologies based on additive manufacturing, especially in the case of parts made of plastic materials. One of the accessible processes for making plastic parts is fused filament fabrication. In many situations, when using fused filament fabrication, it is necessary to obtain surfaces characterized by certain values of roughness parameters. Several factors can influence surface roughness. Some of these factors consider the materialization conditions of the 3D printing process. Starting from the hypothesis that the cooling conditions and the surface position can influence the roughness parameters values, experimental tests were carried out by modifying the values of the two factors. The experimental results were mathematically processed, and power function type mathematical models were determined for the roughness parameters Rz, Rt, Rp, Ra, Rq, Rc. These models provide information on the direction of action, the intensity of the influence exerted by the cooling conditions, and the angle of inclination of the test sample surface on the values of the mentioned roughness parameters.

Surface Structure Analysis of X12CrNiMoV12-3 and X6CrNiTi18-10 Steel Samples Processed by Laser Shot Peening (LSP)

The aim of the experiment was to verify the influence of the chosen strategy of laser shot peening (LSP) on the structure and surface properties of samples made of martensitic steel X12CrNiMo12 and austenitic steel X6CrNiTi18-10. The analyses performed consisted of surface topography analysis of the samples, using a confocal microscope, Olympus LEX|T OLS 5000 and metallographic analysis using a Carl Zeiss Observer Z1m light microscope and a Tescan Mira 3 scanning electron microscope. The metallographic analysis was complemented by the measurement of microhardness HV0.01, which was performed using a Struers DuraScan semi-automatic hardness tester. The LSP process introduced plastic deformation into the surface layer of both materials analysed. The plasma and shock wave generated during the process further affected the surface roughness of both tested materials, which was reflected by an increase in the value of the roughness parameter Rz. Microhardness measurements showed that the influence of the LSP process can increase the surface hardness of the material. Metallographic analysis using light microscopy methods failed to identify differences between the structure near the shot peened surface and the non-peened surface, probably due to the coarse grain structure of both materials analysed.

Wood Surface Roughness Prediction Modeling Depending on Influential Cutting Variables

Paper presents the design of experiment and determining mathematical model to calculate roughness parameter of wood planned surface. For design of experiment three different types of solid wood were taken and processed on the planner with three different displacements and three different cutting speeds. After measuring the roughness parameter Rz, experimental results were obtained on the basis of which the central composite plan of the experiment was made. Based on that, a model of roughness parameter Rz was made, which is adequate and with high accuracy. The significance of the model coefficients was determined using the R software and the results were presented using the Design Expert software.

ANÁLISE EXPERIMENTAL DE ESTAMPABILIDADE DA CHAPA DE AÇO ASTM A653 DURANTE O PROCESSO DE ESTAMPAGEM INCREMENTAL POR PONTO ÚNICO E AVALIAÇÃO DA RUGOSIDADE IMPRESSA NA SUPERFÍCIE CONFORMADA

This study aims to evaluate the behavior of ASTM A653 CS-A G90 steel in the process of Incremental Sheet Forming – ISF, based on the following parameters: diameter of the tool (Dt in mm) and the vertical step size between consecutive contours (∆z in mm). The experiments were based on a variation of the ISF process, called Single Point Incremental Forming - SPIF. In this study, seventeen tests were conducted using a punching tool with diameters (Dt ) of 5, 6 and 8 mm and vertical steps (∆z) of 0.4, 0.6 and 0.8 mm, intending to evaluate the true strain to the ISF process and the surface finishing measured by roughness parameter (Rz). Whereas, for the execution of practical testing, the resources used were a CNCmachining center with three axes, tools for incremental forming and a sheet-press device. As a result, greater depths were achieved using an incremental step of 0.4 mm. In additional tests, it came to attention that the diameter of the tool was also an important parameter when it is desired to increase the formability and greater depths are obtained when using small diameters. It can be observed yet, there is a tendency to increase the roughness parameter Rz when using greater vertical steps ∆z

ON THE EFFECT OF THE SIDE FLOW OF 316L STAINLESS STEEL IN THE FINISH TURNING PROCESS UNDER DRY CONDITIONS

The article presents the results of the research on the plastic flow in the finish turning of 316L (X2CrNiMo17-12-2) stainless steel under dry cutting conditions. The steel was turned at variable cutting speeds and a constant depth of cut. The investigations were based on the Parameter Space Investigation method (PSI) which allowed minimizing the number of test points. It was observed that the phenomenon of slide flow occurred in the range of cutting speeds and feed rates under examination and its intensity depended on the values of these parameters. The phenomenon was more intense in the range of medium and higher cutting speeds and lower feed rates. The side flow results in significant changes between the real and theoretical values of roughness parameter Rz, which range from 40% up to even 330%.

Evaluation of performance of uncoated cemented carbide cutting tools at longitudinal turning at cutting velocity 3–500 m/min and influence of coating

The paper provide study of performance of uncoated and coated cemented carbide cutting tools at longitudinal turning at cutting velocity 3–500 m,min −1 and quantify the improvement through parameter – tool life. Furthermore, the paper guides and physically justifies the behavior in the cutting zone based on the roughness parameter Rz ( Ra ) of the workpiece, the machining forces and the tool life in the range of speeds from a minimum of 3 to 500 m.min −1 for cemented carbide cutting tools - uncoated and coated. Generally, the reasons for using coatings are known. However, the differences and benefits of coatings are analyzed in more detail for cemented carbides and a wide range of speeds with estimation of improvement of tool life.

Influence of thermal and electrochemical oxidation on the mechanical and corrosion properties of titanium alloy

In this paper thermal oxidation and electrochemical anodizing processes were used to produce titanium oxide films on titanium alloy and to examine the effects of oxidation on mechanical and corrosion properties. The surface morphology oxide films, thickness and chemical composition of the surfaces were evaluated using scanning electron microscopy and energy dispersive spectroscopy. The microhardness of titanium oxide films prepared at different experimental conditions is maintained between 8, 2 GPa and 9, 6 GPa, measured by ultra micro hardness tester. The microhardness increased with temperature and voltage. The values of roughness parameters Rz, Rt and Ra indicate a somewhat less roughness of the anodized samples. The values of the roughness parameter Rk are nearly identical for both groups of samples. The cyclic polarization tests showed that none of the tested samples were susceptible to localized corrosion. The oxide films produced by anodic oxidation on titanium alloy showed a higher corrosion resistance than the ones produced by thermal oxidation.

Changes in the surface roughness of optical glasses in a humid environment

Long-term testing of silicate and borate optical glasses is performed in a humid environment. Products of water reacting with glass components are shown to form on the borate glass surface, causing an increase in the roughness parameter Rz. Pretreatment in hexamethyldisiloxane vapors reliably protects glasses from aggressive moisture. Silicate optical glasses are more resistant to humidity and do not require pretreatment. Roughness parameter Rz is found to be an inadequate metric of the roughness of the surface with a protective coating, owing to the limitations of its determination. Topographic measurements are more reliable in this instance.

Deposition, morphology and functional properties of layers based on DLC:Si and DLC:N on polyurethane

DLC:Si and DLC:N (diamond-like carbons doped with Si or N) functional layers in different configurations are deposited on polyurethane (PU) for bioengineering applications using CCP (capacitively coupled plasma) discharge generated in the PE CVD (plasma-enhanced chemical vapor deposition) system. Scanning electron microscopy (SEM) observations show that the obtained single and multilayers are continuous and well adherent to the substrates, but they differ in surface morphologies. DLC:Si layers form granular-like outer surfaces, while DLC:N ones a mosaic structure of plain areas. Topography analyses by atomic force microscopy (AFM) and optical profilometry reveal that Si-doped layers are characterized by significantly higher surface roughness (Ra ca. 5 nm) in comparison to N-doped layers (Ra ca. 0.3 nm) and also higher values of profile roughness parameter Rz (up to 32 μm vs. about 13 μm). Energy-dispersive X-ray spectroscopy (EDS) analysis indicates the homogenous chemical composition of the layers. DLC:N layers, are characterized by significantly higher polar component of surface free energy (up to ca. 5.0 mJ/m2). DLC:Si layers exhibit higher values of diiodomethane contact angle (up to ca. 90°) compared with DLC:N layers (up to ca. 55°). The attenuated total reflectance Fourier transform infrared spectroscopic measurements (ATR-FTIR) of the layers reveal that the addition of silicon to the DLC structure increases the content of terminal CHn bonds (n = 1, 2, 3) as well as beneficial Si–H and Si–CHn bonds, which significantly reduce the internal stresses in the layers. Both DLC:Si and DLC:N layers exhibit no cytotoxic effects using the human osteoblast-like cell line and human keratinocytes.

Surface roughness in laser powder bed fusion – Interdependency of surface orientation and laser incidence

Additive Manufacturing (AM) offers the opportunity for the manufacture of innovative parts with complex geometries and new possibilities regarding complex part design. However, the relatively high surface roughness of as-built parts is a considerable limitation and one of the challenges in AM. Laser powder bed fusion (L-PBF) is one AM technique for the manufacture of metallic serial parts. Although the effect of various process parameters on the surface roughness in L-PBF has been studied, a prediction of surface roughness at the pre-processing stage has not been achieved yet. The interdependency of the surface orientation and the laser incidence, although it is mentioned in literature, is still not yet analyzed or quantified. Therefore, the novel parameter surface laser relation angle ζ is introduced to quantify this interdependency and act as a parameter to predict surface roughness. By using a constant laser relation angle ζ the range of roughness parameter Ra on surfaces across the entire build platform can be decreased from 19 μm to 11 μm in comparison to the usage of a constant surface normal polar angle α. By this method the standard deviation is decreased from 5 μm to 2 μm as well with a constant arithmetic mean of 24 μm on both methods. Similar behavior can also be seen for the roughness parameter Rz in this work. The results achieved so far lay the basis for a homogenization of the surface roughness across the entire build platform.

Variation of Relief Topography and Hardness of Surface Layers of Materials Due to Impact-Oscillatory Loading

It was shown previously that cyclic loading can be used to extend the fatigue life of sheet plastic materials subjected to the preliminary impact-oscillatory loading. This type of loading causes dynamic non-equilibrium processes (DNP) in materials, which lead to the formation of dissipative structures in materials and on their surface. The density of these dissipative structures is less than that of the base metal. In this paper, the results of investigations into the relief and hardness of surface layers modified by impact-oscillatory loading are analyzed on the example of five structural materials. The signs of a regular, orderly system of microextrusions formed on flat surfaces of all materials due to DNP are considered along with the alignment of roughness parameters Rz and Ra of relief profiles. The effect of impact-oscillatory loading is one of the main causes that lead to the extension of the fatigue life of materials.

Effect mechanism and equivalent model of surface roughness on fatigue behavior of nickel-based single crystal superalloy

The global objective of this study was to systematically research the rule and mechanism how surface roughness affects the fatigue property of nickel-based single crystal superalloy. Fatigue tests of specimen with various levels of surface roughness were conducted at 980 °C and measured surface topography models were used to perform FE analysis based on crystal plasticity theory and fatigue damage model considering the resolved shear stress and slip rate of slip systems. Eventually, an geometrical equivalent simplification model with surface roughness parameters Rz, Rsm and Ra as modeling parameters for predicting fatigue life more convenient is proposed. Results indicate that micro-defects caused by surface roughness generate stress, plastic strain and damage concentration under fatigue load, which generate fatigue crack initiation, and greater surface roughness produces more severe concentration. The error between simulation prediction life and test result is within 3 times error band.

Study of technological parameters of steel Domex when high speed machining by monolithic ceramic milling tool

Abstract Experiment includes the study and identification of monolithic ceramic mining tools by machining the Domex 700 steel that belongs to the group of tough metals with high tensile strength. During the process of machining, the substandard high cutting speeds were used. Identification of ceramic mining tools included the analysis of cutting edge wear and the construction of map of surface roughness parameter Rz dependence on the change of cutting conditions for a given range (machine and material).

Evaluation of the surface profile obtained by abrasive jet machining

The abrasive jet machining is a machining method based on the effects generated by the action of the abrasive particles sent to the workpiece surface to be machined by means of a high pressure gas jet. Essentially, the obtained surface could be considered as constituted by chaining microcraters resulted as a consequence of the abrasive particles action. Taking into consideration the possible influence exerted by some abrasive jet machining process input factors, an experimental research was developed. By mathematical processing of the experimental results, empirical mathematical models were determined to highlight the influence exerted by the average dimension of the abrasive particles, the distance between the nozzle and the flat surface of the test piece and the impact angle on the surface roughness parameter Rz. In order to evaluate the similarities between distinct zones of the machined surface profile, the value of the Pearson’s coefficient was also determined.

Wpływ parametrów technologicznych na chropowatość powierzchni po toczeniu oraz predykcja chropowatości z użyciem sztucznych sieci neuronowych

The purpose of this investigation was to determine whether and to what extent the technological parameters of turning (feed, cutting speed) affect selected surface roughness parameters of aluminum alloy EN-AW 7075 (AlZn5.5MgCu). The principal findings indicate a significant impact of feed and show on the surface roughness and simultaneously show that cutting speed has no effect on the value of surface roughness parameters under investigation. An artificial neural network was employed to evaluate the prediction of surface roughness parameter Rz in turning.

The use of Rz roughness parameter for evaluation of materials behavior to cavitation erosion

It is well known that the cavitation eroded surfaces have a porous appearance with a pronounced roughness. The cause is the pitting resulted from the impact with the micro jets as well as the shock waves both determined by the implosion of cavitation bubbles. The height and the shape of roughness is undoubtedly an expression of the resistance of the surface to the cavitation stresses. The paper put into evidence the possibility of using the roughness parameter Rz for estimating the material resistance to cavitation phenomena. For this purpose, the mean depth erosion penetration (MDE-parameter, recommended by the ASTM G32-2010 Standard) was compared with the roughness of three different materials (an annealed bronze, the same bronze subjected to quenching and an annealed alloyed steel), both measured at four cavitation erosion exposure (30, 75, 120 and 165 minutes). The roughness measurements were made in 18 different zones, disposed after two perpendicular diameters, along a measuring lengths of 4 mm. The results confirm the possibility of using the parameter Rz for estimating the cavitation erosion resistance of a material. The differences between the measured values of Rz and those of the characteristic parameter MDE are of the same order of magnitude as those obtained for MDE determination, using more samples of the same material.