Surface Roughness Factor Research Articles

Electrical Discharge Machining of Inconel 718 using Cryo-Processed Rotary Cu-Electrode

This paper focuses on the impact of machining factors on surface quality in electric discharge machining (EDM) of Inconel 718. Drilling has been performed by a cryogenic treated copper tool. Experiments were accompanied by dissimilar machining factors viz. tool diameter, discharge current, pulse on time pulse off time, tool rotation and hole depth. The thickness of work piece material remains constant. Surface roughness is measured by optical surface profiler. Taguchi based L 18 orthogonal array of experimental design was employed to accomplish machining. Analysis of variance (ANOVA) has been employed to find out optimum factors for minimum surface roughness (SR). It was found that pulse off time, pulse on time and tool rotation are greatest affecting factors that affects SR for cryo-treated Cu tool electrode. Tool diameter is least affecting factor that affects SR. A linear regression model has been developed to find out optimum combination for SR of Inconel 718 work piece.

Experimental investigation of milling operation on GFRP composites

This work attempts to investigate the aspects of machining performance and its optimization during milling operation of glass fibre reinforced composites. Using Taguchi’s design approach, experiments are conducted as per the orthogonal array. The three input parameters considered for the milling operation are the number of flutes, feed rate and cutting speed. The various responses studied during this milling operation are machining force, cutting torque, surface roughness and delamination factor. Also optimization of the machining parameters (ie) number of flutes, feed rate and cutting speed are carried out on milling in order to minimize the surface delamination, machining force, cutting torque and delamination factor. The optimized results obtained after the study are found to be as feed rate of 0.05mm/rev, number of flutes as 4 and cutting speed as 1500 rpm and under these conditions the milling operation performed yielded better surface characteristics.

Analysis of nitrogen recombination activity on silicon dioxide with stagnation heat-transfer

Investigation of surface recombination activity of nitrogen on certain materials is crucial in the design of hypersonic re-entry vehicles. In the present work, an experimental study using a conventional shock tube facility has been conducted to investigate the phenomena of nitrogen recombination. Stagnation heat-transfer measurements were conducted behind reflected shock waves in a dissociated shock-tube flow for a mixture of 20% nitrogen and 80% argon. A platinum thin-film gauge was used to measure the stagnation heat-transfer in a shock heated gas mixture under a well-defined test condition. The surface of the heat-transfer gauge was coated with silicon dioxide (SiO2), the principal material used in thermal protection systems (TPS) for the hypersonic vehicles. Spectroscopic analyses were performed for in-depth characterization of the initial surface condition of the test specimen. Recombination activity behavior of nitrogen was evaluated by combining the heat-transfer data with catalytic heat transfer theories. The nitrogen recombination efficiency of silicon dioxide is found to be from 0.0026 to 0.035 at surface roughness factors of 1.01 to 1.10. Compared to the oxygen recombination activity, the nitrogen recombination activity showed a more than five times higher sensitivity to the roughness factor of the SiO2-coated surface.

Study on surface roughness of zirconia ceramics in high efficient and precision grinding process

In order to solve the problem that the surface roughness of engineering ceramics is difficult to control, this paper studied the influencing factors of surface roughness of zirconia ceramic grinding. The effects of grinding depth, grinding wheel speed and workpiece feed rate on surface roughness were analyzed by the orthogonal experiments of zirconia ceramic grinding. On this basis, single factor experiments were carried out respectively, and the optimal combination of process parameters was analyzed. In addition, an empirical formula of surface roughness for the grinding of zirconia ceramics was established based on the experimental results. The results showed that the grinding depth had a great influence on the surface roughness, the grinding wheel speed effect was secondary, and the effect of the workpiece feed rate on the surface roughness was not very obvious. Compared with the measured value, the maximum relative error of the predicted value was less than 5%, which indicated that the empirical formula had a better prediction effect and provided a theoretical basis for reasonable selection of grinding parameters in actual processing.

Does power ultrasound (26 kHz) affect the hydrogen evolution reaction (HER) on Pt polycrystalline electrode in a mild acidic electrolyte?

In this study, we investigated the effects of power ultrasound (26 kHz, up to ∼75 W/cm2, up to 100% acoustic amplitude, ultrasonic horn) on the hydrogen evolution reaction (HER) on a platinum (Pt) polycrystalline disc electrode in 0.5 M H2SO4 by cyclic and linear sweep voltammetry at 298 K. We also studied the formation of molecular hydrogen (H2) bubbles on a Pt wire in the absence and presence of power ultrasound using ultra-fast camera imaging. It was found that ultrasound significantly increases currents towards the HER i.e. a ∼250% increase in current density was achieved at maximum ultrasonic power. The potential at a current density of −10 mA/cm2 under silent conditions was found to be −46 mV and decreased to −27 mV at 100% acoustic amplitude i.e. a ΔE shift of ∼+20 mV, indicating the influence of ultrasound on improving the HER activity. A nearly 100% increase in the exchange current density (jo) and a 30% decrease in the Tafel slope (b) at maximum ultrasonic power, was observed in the low overpotential region, although in the high overpotential region, the Tafel slopes (b) were not significantly affected when compared to silent conditions. In our conditions, ultrasound did not greatly affect the “real” surface area (Ar) and roughness factor (R) i.e. the microscopic surface area available for electron transfer. Overall, it was found that ultrasound did not dramatically change the mechanism of HER but instead, increased currents at the Pt surface area through effective hydrogen bubble removal.

Study of Machining Parameter Optimization in Drilling of Magnesium Based Hybrid Composites Reinforced with SiC/CNT

Recently, researchers and engineers have been interested in the development of hybrid metal matrix composites (HMMCs) for the applications of automotive and aerospace industries owing to their superior properties due to the usage a wide range of material combinations in its manufacturing. The present study focuses on the machining of magnesium based hybrid composites reinforced with CNT (1vol.%) and SiC (2vol.%).The influence of machining parameters such as spindle speed, feed rate, drill diameter and point angle on burr formation and surface roughness on drilling the composites were investigated using Taguchi method. The drilling parameters were optimized by using ANOVA experimental design and also find out the percentage of contribution of each factor. Based on the results, the most influential factor for the burr thickness was spindle speed and point angle. While spindle speed and feed rate were the influencing factors for surface roughness. The analysis revealed that burr height, burr thickness, and surface roughness decreases significantly with an increase in spindle speed.

Enhancement of the performance surface roughness of wire cutting process by additives Nano [AL2O3

Experimental investigation and optimization of machining parameters in Wire EDM in terms adding particles Nano-reinforced titanium alloy composite abstracts among the various mechanical processes, the process of manufacturing in wire electrical discharge machines WIRE EDM is one of the most effective and cost-efficient manufacturing processes in the manufacture of titanium alloys Ti-6242. Ti has been dealt with in this article investigate each of operating parameters such as pulse on time, pulse off time, voltage and current insulating liquid with Nano powder [AL2O3] in WIRE EDM compounds titanium alloy. Experiments on titanium alloy carried out with powder mixture with particles size average of [5 nm]. Operating parameters such as voltage, pulse on time and pulse off time are taking into consideration four factors based on the response surface methodology. The performance of thesis evaluated WIRE EDM for ti-6242 using the surface roughness factor SURFACE ROUGHNESS. Quadratic models were developed between parameters and WIRE EDM responses by regression analysis is. The derived mathematical models are then optimized using Box-Behnken optimization based on desire analysis. The search indicates that the expected values of the model obtained to match the experimental values. Improvement in surface roughness is observed in terms of the values obtained from the Box-Behnken analysis.

Validity of triple-effect model for fluid flow in mismatched, self-affine fractures

Investigation of seepage law of fluid flow through a self-affine, rough fracture has attracted broad attention because of its fundamental importance for complex hydrodynamic problems. Although it is natural to assume that permeability value depends on aperture size, it is hard to determine which is the appropriate relationship between them because of the large number of parameters related to the multi-scale geometries and mismatched behaviors in internal surfaces. Moreover, those parameters are hard to obtain by field observation or laboratory tests. For these, we focused on synthesising mismatched composite topography of natural fractures and numerical simulation of fluid flow through them at pore scale. Firstly, the control mechanism of self-affine property was clarified, and a novel Weierstrass-Mandelbrot (W-M) function was proposed to model self-affine profile as per fractal topography theory. Afterwards, a weighting algorithm was developed to construct the composite topography of fractures accounting for the mismatched behavior. Finally, the effects of mismatched behavior, hydraulic and surface tortuosities on fracture flow were systematically analyzed by numerical simulations using Lattice Boltzmann methods (LBM) at pore scale. Our investigation indicates that the aperture distribution is dominated by the mismatched range between internal surfaces, however the hydraulic and surface tortuosity effects are approximately scaled by 2(H−1) (H is the Hurst exponent) with the mean aperture despite of its distribution. Moreover, it was found that the local surface roughness factor, accounting for effects from surface geometries with size smaller than the value of mean aperture, is stationary at long range and inversely proportional to fracture permeability. Based on above discussions, the validity of triple-effect model for permeability prediction of mismatched self-affine fractures was established.

Study of Surface Roughness and MRR in Turning of SiC Reinforced Al Alloy Composite Using Taguchi Design Method, ANN and PCA Approach under MQL Cutting Condition

This paper emphases on the effect of various machining constraint on surface roughness and material removal rate in turning SiC reinforced Al alloy composite through taguchi orthogonal array based experimental analysis which has been further optimized using principal component analysis (PCA). Experimental investigation has been conducted under minimum quality lubricant (MQL) cutting environment. Palm oil has been used as lubricant where flow rate and pressure were kept at 120 ml/hr and 8 bar. The whole experiment has been designed using L25 orthogonal array having three input parameters and five different level to measure surface roughness and material removal rate. Taguchi S/N ratio-based optimization has been implemented where smaller the better criteria has been used for surface roughness whereas larger the better criteria has been used for material removal rate. From Analysis of variance, it is observed that cutting speed and feed rate are the most prominent factor for surface roughness. Nevertheless, Depth of cut and cutting speed are the most dominant factor for material removal rate. While comparing the predicted output values with experimental values, MAPE value is found in the range of 0.23 % for surface roughness and 0.045 % for material removal rate which is in very much tolerable range. Correlation coefficient value for experimental values of the resultant output is 0.98286 and 0.99869 respectively which signifies the effectiveness of the whole experiment. Subsequently, machining parameters were optimized using PCA technique. To attain satisfactory response values, depth of cut, cutting speed and feed rate need to be at 0.85 mm, 396 m/min and 0.16 mm/rev respectively. By applying the model, surface roughness of 0.7257 μm and MRR of 53856 mm3/min can be obtained. Keywords: SiC reinforced Al alloy; Turing; Minimum Quality Lubricant; Surface Roughness; MRR; Taguchi orthogonal array; Principal component analysis

INVESTIGATION OF SURFACE MORPHOLOGY OF DRILLED CFRP PLATES AND OPTIMIZATION OF CUTTING PARAMETERS

In this study, the carbon fiber reinforced polymer (CFRP) composite material was drilled using different parameters ([Formula: see text] and [Formula: see text] Point Angle, 30, 60 and [Formula: see text] cutting speed and 0.06, 0.08 and [Formula: see text] feed rate). Experimental parameters were designed according to full factorial design method and the results were analyzed using Taguchi L18 experimental design. The results of the study show that the lowest surface roughness values are 0.1958 and [Formula: see text]m with the cutting speed of 90 [Formula: see text] and feed rate of [Formula: see text] in the Point angles of [Formula: see text] and [Formula: see text], respectively. When the results of Anova analysis were evaluated, parameters (feed speed, cutting speed and end point angle) according to the effect ratios on surface roughness were formed at the rates of 41.06%, 33.13% and 5.07%, respectively. The most suitable parameters according to S/N ratios were determined using A2B3C1 factors for the average surface roughness.

Multi-objective optimization of wire electrical discharge machining of 20MnCr5 alloy steel

PurposeWire electric discharge machining (WEDM) is a non-conventional machining process, which is used to provide difficult and intricate shapes. The purpose of this research work is to apply Taguchi’s technique to optimize the process parameters in WEDM. Alloy steel 20MnCr5 has been selected as base material for experimentation. The effects of the input process parameters such as wire type, pulse-on time, pulse-off time, peak current, wire feed rate and servo voltage have been calculated on the material removal rate (MRR) and surface roughness (Ra) in WEDM operation.Design/methodology/approachIn the research work, Taguchi's technique is applied to optimize the process parameters in WEDM.FindingsANOVA indicated that pulse-off time was the most significant factor for the MRR, and servo voltage was the most significant factor for surface roughness (SR). As a part of the project, 20MnCr5 was machined in wire electric discharge machine, and the optimal control parameters were found to get higher MRR and better SR using Taguchi’s technique.Originality/valueTo the best of authors’ knowledge, after reviewing the literature, materials including alloys of metals such as 16MnCr5 and 20MnCr5 have not been investigated so far, and research regarding machining of these materials is limited. Therefore, 20MnCr5 material has been selected for this research work to generate WEDM data.

Optimizing the Process Parameters of Drilling on Aluminium Alloy 7075 using taguchi and Anova Techniques

In many material processing and manufacturing industries quality and productivity are two important requirements but these are more antithetical criteria in any machining operations. So, it is vital to optimize the productivity and quality simultaneously. The main objective of this paper is to optimize the process parameters of drilling operations such as cutting speed, feed, and point angle on aluminum alloy 7075. Al 7075 is one of the multifunctional materials in various applications. Taguchi is mostly used for data analysis and optimization of process parameters for getting maximum material removal rate and least surface roughness factor. Machining operations were conducted on CNC milling machine. The number of drilling experiments was performed on aluminum 7075 using HSS drill bit on CNC milling machine. The investigation of variance (ANOVA) was engaged to find the most notable control factors affecting the material removal rate & surface roughness. The conclusions of present work were drawn from several experimental trails; it was found that at the 9th experimental trail, point angle was most significant x factor for surface roughness and feed is the most affecting factor for material removal rate.

Electrochemical Studies of Hydrogen Peroxide Oxidation on a Nanoporous Gold Surface: Fundamental and Analytical Applications

A nanoporous gold (NPG) surface with high electroactive surface area and roughness factor was prepared via anodization-electrochemical reduction method and was used as a new platform to study the electrochemical oxidation of hydrogen peroxide (H2O2). Field-emission scanning electron microscopy (FE-SEM) analysis, cyclic voltammetry, and amperometry techniques were employed for structural morphology and electrochemical studies. The H2O2 oxidation peak potential was significantly shifted (∼0.23 V) towards a less positive direction with increased current response at the NPG surface compared to that of a bare gold electrode. The mechanism for the H2O2 anodic oxidation at the NPG surface was proposed based on the calculated transfer coefficient (α = 0.32) and the total number of electrons involved (n = 2.0) in the electrochemical process. Besides, the diffusion coefficient (D) of H2O2 in PBS solution was also calculated using the Randles-Sevcik equation (2.18 × 10−5 cm2 s−1). In addition, the analytical application of the NPG electrode was demonstrated by amperometric detection of H2O2 at a relatively less positive potential (0.57 V). The current increased proportionally to H2O2 concentration in the linear range of 0.01 to 1.8 mM and the detection limit was found to be 0.6 μM (S/N = 3).

Pore-Scale Modeling of Fluid-Fluid Interfacial Area in Variably Saturated Porous Media Containing Microscale Surface Roughness.

A pore-scale model is developed to simulate fluid-fluid interfacial area in variably saturated porous media, with a specific focus on incorporating the effects of solid-surface roughness. The model is designed to quantify total (film and meniscus) fluid-fluid interfacial area (Anw ) over the full range of wetting-phase fluid saturation (Sw ) based on the inherent properties of the porous medium. The model employs a triangular pore space bundle of cylindrical capillaries (BCC) framework, modified with three surface roughness-related parameters. The first parameter (surface roughness factor) represents the overall magnitude of surface roughness, whereas the other two parameters (interface growth factor and critical adsorptive film thickness) reflect the micro-scale structure of surface roughness. A series of sensitivity analyses was conducted for the controlling variables, and the efficacy of the model was tested using air-water interfacial area data measured for three natural porous media. The model produced good simulations of the measured Anw data over the full range of saturation. The results demonstrate that total interfacial areas for natural media are typically much larger than those for ideal media comprising smooth surfaces due to the substantial contribution of surface roughness to wetting-film interfacial area. The degree to which fluid-fluid interfacial area is influenced by roughness is a function of fluid-retention characteristics and the nature of the rough surfaces. The full impact of roughness may be masked to some degree due to the formation of thick wetting films, which is explicitly quantified by the model. Application of the model provides insight into the importance of the interplay between pore-scale distribution and configuration of wetting fluid and the surface properties of solids.

Taguchi Optimisation In Machining EN18 Using Coated Tool Under Dry and MQL Condition

Turning is one of the initial basic machining operation that prevails in assembly and production process. Modern techniques have been practices in rapid and eco-friendly production systems. Present study deals with the investigation of turning process on EN 18 steel which is been shown its existence in automobiles industries. Turning operation was performed using a coated tool insert with varying cutting speed (100, 125 and 150 mm/min), feed rate (0.05, 0.5, 0.15 mm/rev) and depth of cut (0.4, 0.8, 1.2 mm) at both dry and MQL conditions. The results obtained was compared to optimize the effect of minimum quality lubrication on surface roughness. Experimentally it was observed that speed of 100 m/min with combination of feed of 0.05 mm/rev and 0.4 mm depth of cut was found to be optimized for surface roughness in both the cases. The mathematical model generated for surface roughness and MRR for both dry and MQL turning models having better regression fit as it closer to 100. From ANOVA analysis feed was proved to be the highest contributing factor for surface roughness and for MRR speed is the most significant factor for both dry and MQL turning

Determination of Surface Roughness Throughout CNC Turning of ASTM 316 Steel Expending Taguchi Method

Plan of experiment involving Taguchi method got developed and executed to gauge impact of various machining variables (V, F and D) on surface roughness throughout CNC turning of ASTM 316 steel using coated carbide insert. Research findings through different mathematical analyses provided the effective guideline for choosing appropriate machine settings to realize surface roughness within the recommended range during stated turning operation. Ideal machining situations got determined to minimize the surface roughness (here surface roughness factors Ra with Rz) in turning of the same. Feed remains observed as paramount momentous variable for workpiece surface roughness. Furthermore, cutting speed remains observed as subsequent paramount momentous variable for workpiece surface roughness. Additionally, depth of cut remains observed as least paramount momentous variable for workpiece surface roughness, Rz only, however, depth of cut got absolutely insignificant impression on Ra. Present investigation clearly reveals that multicoated carbide inserts performed splendidly at optimal machining variables combination of V = 150 m/min, F = 0.10 mm/rev with D = 0.4 mm. Calculated ideal limit of sample surface unevenness, Ra and Rz are 0.16 μm ≤ Ra ≤ 0.52 μm and 1.4 μm ≤ Rz ≤ 3.1 μm, respectively. Moreover, surface roughness, Ra is also within stipulated precarious limit of 1.5 μm (i.e. Ra < 1.5 μm) for turning with coated carbide inserts.

Electrocatalytic activity for the hydrogen evolution of the electrodeposited Co–Ni–Mo, Co–Ni and Co–Mo alloy coatings

The electrocatalytic activity for the HER of the ternary Co–Ni–Mo and the binary Co–Ni and Co–Mo alloy coatings is investigated in 1 M KOH solution. The surface morphology and the structure of the studied coatings is characterized by SEM and XRD analysis. The electrocatalytic activity for the HER is evaluated using cyclic voltammetry, electrochemical impedance spectroscopy, cathodic polarization and chronopotentiometry techniques. XRD analysis reveals that all studied coatings are composed of the Co hcp structure. However, alloy deposits with Mo is characterized by more nanocrystalline structure. Electrochemical experiments reveal superior electrocatalytic activity of coatings with Mo in comparison to Co–Ni alloy. This is the results of larger real surface area of Co–Mo and Co–Ni–Mo alloys, which is confirmed by the higher surface roughness factors (Rf) calculated based on the EIS results. The ternary alloy coating is characterized by the highest Rf parameter and the highest catalytic activity for the HER.

Optimization of Process Parameters That Affects Hole Quality Characteristics in Drilling Of Syntactic Foams Using Artificial Neural Network Model and Particle Swarm Optimization

The drilling is known popular and common mechanical operation which is performed frequently during manufacturing of automotive and aerospace related parts, it is important to study the manufacturability of any novel engineering materials developed and subjected for machining more often as drilling a hole which is required for the purpose of assembly. In this regard the proposed work aims at study of drilling process parameters on newly developed class of polymer based composites. Cenosphere or fly ash acts as a filler material which is a by-product of coal combustion used along with epoxy to produce syntactic foam. The preparation of cenosphere based epoxy composites is done using hand layup technique. The controllable factors in the presented study identified such as cutting speed, feed rate and drill diameter are suspected to have effect on drilled hole quality characters, such as surface roughness and delamination factor. Syntactic foams of 40% by weight are fabricated. A complete factorial design has been selected to perform drilling experiments and recommended drilling quality aspects are analyzed using RSM based quadratic relationships. The relationship of RSM revealed that Ra and Fd are varying non-linearly for selected input variables. The optimization of selected parameters is performed and it is seen that Ra of 0.2 microns and Fd 0.99 are achieved at cutting speed of 55m/min, feed rate of 0.05mm/rev and using drilling tool of diameter 16mm.

MCDM Optimization of Parameters for Wire-EDM Machined Stainless Steel using Hybrid RSM-TOPSIS, Genetic Algorithm and Simulated Annealing

In this investigation, the influence of WEDM process constraints on tool wear rate, kerf width, surface roughness of SS 304 grade stainless steel was studied. Fifteen experimental runs were carried out based on Box-Behnken method of Response surface methodology and TOPSIS method was used for finding an optimum parameter setting. From the ANOVA results, pulse ON time was found as most significant factor for tool wear rate, kerf width and surface roughness. Genetic Algorithm and Simulated Annealing was also used for the calculation of the optimum setting along with the forecast of fitness values. It was found that every optimization technique gives similar factor setting.

Multi Response Optimization of Process Parameters in Drilling Operation for Jute and Basalt Fabric Composite Material

Natural fabric Reinforced polymer (NFRP) composites are the materials by a matrix and a reinforcement of natural fibre. NFRPs are the materials with low density, high molding flexibility, environmentally friendly and have wide range of applications extending from products of commodity to aerospace, defence, automobile spare parts, and bicycle frames applications. In this work the effect of cutting parameters in drilling Natural fabric reinforced composites were studied. Experiments were conducted to study the effect of drill bit diameter, spindle speed and feed rate on Material Removal Rate (MRR), Surface Roughness, Circularity of Hole and Delamination Factor. Theoretical calculations are done to calculate Material Removal Rate and Delamination Factor. Surface Roughness and Circularity of Hole measured by Surface Roughness Tester and Coordinate Measuring Machine (CMM) respectively. The input parameters considered were 6mm, 8mm and 10mm diameter drill bits, spindle speeds of 600rpm, 1200rpm & 1800rpm, feed rates of 0.1rev/min, 0.2rev/min and 0.3rev/min. Experiments were carried as per Taguchi Experimental Design (L9) to get the optimum values of MRR, Surface Roughness, And Circularity Of Hole and Delamination Factor. Optimization was done using Taguchi Analysis, Grey Taguchi Analysis and Multi Attribute Decision Making (MADM) Method. The optimal solution for the multiple response system of drilling of NFRP were diameter of drill bit of 10 mm, Spindle speed 600 rpm and at 0.3 mm/rev feed rate. MADM process concluded that, Circularity of Hole was most preferred response than followed by Material Removal Rate, Surface Roughness and Delamination Factor.