Surface Roughness Factor Research Articles

Investigation of Surface Roughness and Material Removal Rate on Machining of TIB2 Reinforced Aluminum 6063 Composites: A Taguchi’s Approach

Abstract The utilization of TiB2 particles reinforced aluminum (Al6063) metal matrix composite materials in many different engineering fields has undergone a tremendous increase. Accordingly, the need of accurate machining of composites has increased enormously; an attempt has been made to assess the factors influencing surface roughness and material removal rate on machining the composite. The orthogonal array, the signal-to-noise ratio, and analysis of variance were employed to study the performance characteristics in turning operations of 5 and 10 wt. % TiB2 particles reinforced aluminum (Al6063) metal matrix composites. Taguchi method was used to find the optimal cutting factors for surface roughness (Ra) and material removal rate (MRR). Three cutting factors namely speed; feed and depth of cut were optimized with considerations of Ra and MRR. The experimental plan and analysis was based on the Taguchi L27 orthogonal array with three cutting factors using carbide tool (K20). The optimal parametric combination for K20 carbide insert was found to be feed, speed and depth of cut. The analysis of variance (ANOVA) result shows that feed the most significant process parameter on surface roughness followed by speed. For MRR result show that the speed and the feed are the significant parameters followed by the composition of composite material.

Selection of optimal controllable factors for surface roughness in turning of titanium alloy using eco friendly cutting fluids

Surface finish plays a vital role in service components, to ensure a great reliability of sensitive aeronautical components, surface integrity of titanium alloys should be satisfied. Therefore, it is required to optimize process parameters like cutting speed, feed and depth of cut while machining of titanium components for better surface finish.In this study, the optimization and effect of machining parameters on surface roughness in a turning operation is investigated by using the Taguchi’s robust design methodology. The experimental studies are conducted under varying cutting speeds, feed rates and depths of cut. An orthogonal array, analysis of mean (AOM) and the analysis of variance (ANOVA) are employed to study the performance characteristics in the turning of commercial Ti-6Al-4V alloy using uncoated carbide cutting tool with karanja and rice bran oils are as coolants. The results observed that the feed rate is the most influential factor on the surface roughness for both karanja and rice bran oils. The minimal surface roughness value is observed for karanja oil than that of rice bran oil. The optimum process parameters found for karanja oil at a cutting speed of higher level, feed rate of lower level and depth of cut is of moderate level. Similarly, the optimum process parameters found for rice bran oil at a cutting speed of higher level, feed rate of lower level and depth of cut of higher level.

Effects of Process Parameters on Surface Roughness and MRR in the hard turning of EN 36 steel

In the present study, Experimental investigation of the effects of various cutting parameters on the response parameters in the hard turning of EN36 steel under the dry cutting condition is done. The input control parameters selected for the present work was the cutting speed, feed and depth of cut. The objective of the present work is to minimize the surface roughness to obtain better surface finish and maximization of material removal rate for better productivity. The design of experiments was done with the help of Taguchi L9 orthogonal array. Analysis of variance (ANOVA) was used to find out the significance of the input parameters on the response parameters. Percentage contribution for each control parameter was calculated using ANOVA with 95 % confidence value. From results, it was observed that feed is the most significant factor for surface roughness and the depth of cut is the most significant control parameter for Material removal rate.

Surface-wettability and Structural Colouration Property of Certain Rosaceae Cultivars with Off-to-dark Pink Appearances

The present work reports microstructure-based wettability and reflectance responses of three varieties of Indian Rosaceae (Rosa) cultivars, viz. white rose (Rosa chinensis var spontanea), light pink rose (Rosa chinensis var minima) and dark pink rose (Rosa chinensis var minima). As for wettability, static and advancing and receding Contact Angles (CA) have been measured, for each type of matured rose petals. The surface roughness factors (rϕ), which are largely dependent on the micro-papillae assembly within the rose petal, are estimated to be, 2.74, 2.27 and 2.94 in case of White (W), Light Pink (LP) and Dark Pink (DP) petals; respectively. Moreover, the respective Contact Angle Hysteresis (CAH) values are measured as 51°, 27° and 59°. In order to exploit structural colouration through the reflectance characteristics, the specimens were dipped in three different media of different Refractive Indices (RI), viz. ethanol (RI = 1.36), propanol (RI = 1.39) and glycerine (RI = 1.47) for about 24 h. Upon ethanol and propanol adsorption, the LP and DP rose petals showed unusually similar reflectance patterns over a wide range of wavelengths, thus indicating a common microstructural share and structural colour contribution. The wetting-dewetting and structural colouration in natural systems, to a great extent, are dictated by the surface structure and solid-liquid and liquid-air interfaces, not only offer fundamental interest but also give scope for mimicking in artificial designs of technological interest.

Branched multiphase TiO2 with enhanced photoelectrochemical water splitting activity

An efficient hierarchical structure, nano-branch containing anatase TiO2 nanofibers and rutile nanorods, was prepared via the combination of the electrospinning and hydrothermal processes. This novel configuration of TiO2 multiphase possessed higher surface area, roughness, and fill factors compared with each single phase component prepared in the same condition, which significantly enhanced its light absorption. Our experimental results showed that within the interface of multiphase TiO2, the heterojunction promoted the charge separation and improved the charge transfer rate, leading to higher efficiency for photoelectrochemical water splitting. The photocurrent density of the nano-branched TiO2 electrode could reach 0.95 mA/cm2, which was almost twice as large as that of the pristine TiO2 nanorod. Our work provides a simple and feasible routine to synthesize complex TiO2 nanoarchitectures, which lays a foundation for improving energy storage and conversion efficiency of TiO2-based photoelectrodes.

Optimization of Performance Parameters in Drilling Process for Minimizing the Burr Formation

Presently a-days precision manufacturing has picked up its significance in all assembling industries. The best product dimensions at low cost with minimum time become a measure of concern. The drilling process imparts more than 30% of all the metal removing operations done on a job or assembly. The burr is a plastically deformed material, generated during drilling is unnecessary output and reduces the product acceptability, often lowers the surface quality of the product requires deburring which increases the cost of product. Burr is caused due to improper machining, tooling and environmental parameters. Total elimination of burrs during drilling process is a difficult task but using proper process parameters it can be minimized. In the present experimental study, the optimization of process parameters for minimization of burr formation in drilling process has been carried out for Al6082 plate. The tool type (coated/uncoated), spindle speed, feed rate, and drill diameters were used as the process parameters. Taguchi’s L18 orthogonal has been applied for DOE and drilling of Al6082 plates has been performed using ply-board as a backup support and without using any backup support on CNC drilling machine. The burr height and surface roughness were analyzed and optimized using S/N ratio and ANOVA and the optimum combinations for burr height and surface roughness has been found from S/N plots. The most influencing factors for burr height and surface roughness have been found from ANOVA tables.

Surface Finish and Back-Wall Dross Behavior during the Fiber Laser Cutting of AZ31 Magnesium Alloy.

Magnesium alloys are of increasing interest in the medical industry due to their biodegradability properties and better mechanical properties as compared to biodegradable polymers. Fiber laser cutting of AZ31 magnesium alloy tubes was carried out to study the effect of cutting conditions on wall surface roughness and back-wall dross. During the experiments, an argon gas chamber was adapted in order to avoid material reactivity with oxygen and thus better control the part quality. A surface response methodology was applied to identify the significance of pulse overlapping and pulse energy. Our results indicate minimum values of surface roughness (Ra < 0.7 μm) when the spot overlapping is higher than 50%. A back-wall dross range of 0.24% to 0.94% was established. In addition, a reduction in back-wall dross accumulations was obtained after blowing away the dross particles from inside the tube using an argon gas jet, reaching values of 0.21%. Laser cutting experimental models show a quadratic model for back-wall dross related with the interaction of the pulse energy, and a linear model dependent on pulse overlapping factor for surface roughness.

Tuning Ni-Foam into NiOOH/FeOOH Heterostructures toward Superior Water Oxidation Catalyst via Three-Step Strategy.

Splitting of water into hydrogen and oxygen has become a strategic research topic. In the two semi-reactions of water splitting, water oxidation is preferred to the four-electron-transfer process with a higher overpotential (η) and is the decisive step in water splitting. Therefore, efficient water oxidation catalysts must be developed. IrOx and RuOx catalysts are currently the most efficient catalysts in water oxidation. However, the limited reserve and high prices of precious metals, such as Ir and Ru, limit future large-scale industrial production of water oxidation catalysts. In this study, we tune inert Ni-foam into highly active NiOOH/FeOOH heterostructures as water oxidation catalysts via three-step strategy (surface acid-treating, electroplating, and electrooxidation). NiOOH/FeOOH heterostructures as water oxidation catalysts only require η of 257 mV to reach a current density of 10 mA cm–2, which is superior to that of IrO2/Ni-foam (280 mV). The high electrochemically active surface area (72.50 cm2) and roughness factor demonstrate abundant interfaces in NiOOH/FeOOH heterostructures, thus accelerating water oxidation activity. The small value (4.8 Ω cm2) of charge transfer resistance (Rct) indicate that fast electronic exchange occurs between NiOOH/FeOOH heterostructures catalyst and reaction of water oxidation. Hydrogen-to-oxygen volume ratios (approximately 2:1) indicate an almost overall water splitting by the double-electrode system. Faraday efficiency of H2 or O2 is close to 90% at 2:1 hydrogen-to-oxygen volume ratio. NiOOH/FeOOH heterostructures exhibit good stability. The results provide significance in fundamental research and practical applications in solar water splitting, artificial photoelectrochemical cells, and electrocatalysts.

Optimization of photochemical machining process parameters for manufacturing microfluidic channel

ABSTRACTIn the present study, the investigation on photochemical machining (PCM) of stainless steel (SS-304) by ferric chloride as etchant is reported. SS-304 is machined by PCM process to obtain accurate dimensions and better geometrical features. Weighted grey relational analysis (WGRA) technique is used in optimization of PCM process parameters. DoE (L27) orthogonal array is applied to evaluate machining parameters, such as concentration of etchant, etching time, and temperature of etchant. The multiobjective optimization technique is used to optimize material removal rate (MRR), surface roughness (Ra), undercut (Uc) and etch factor (EF). Weighted grey relational grade is calculated to minimize Uc and surface roughness and to maximize MRR and EF. The quality characteristics MRR, EF, Uc, and Ra are reporting the improvement after the confirmatory test. The optimum machining parameters are processed to manufacture the microfluidic channel used in biomedical applications. The microfluidic channels and its assembly with Y-type for mixing of fluid with a size of 100 µm, 200 µm, and 300 µm are developed and investigated.

Investigation of CNC Milling Machining Parameters on Surface Roughness

Milling Machining is a widely accepted nontraditional machining technique used to produce parts with complex shapes and configurations. The material is removed in two stages roughing and finishing, the flat end cutter removed the unwanted part of material, then finished by end mill cutter. In milling technique, the role of machining factors such as cutting depth, spindle speed and feed has been studied using Taguchi technique to find its effectiveness on surface roughness. Practical procedure is done by Taguchi Standard matrix. CNC milling is the most conventional process which is used for removing of material from workpiece to perform the needed shapes. The results and relations indicate that the rate of feed is very important factor for modeling surface roughness. The plot of S/N ratio shows that the optimum combination of the milling factors that gives the best value of surface accuracy. The best combination of milling factors has also been predicted to minimize the surface roughness.

Investigation of CNC Milling Machining Parameters on Surface Roughness

Milling Machining is a widely accepted nontraditional machining technique used to produce parts with complex shapes and configurations. The material is removed in two stages roughing and finishing, the flat end cutter removed the unwanted part of material, then finished by end mill cutter. In milling technique, the role of machining factors such as cutting depth, spindle speed and feed has been studied using Taguchi technique to find its effectiveness on surface roughness. Practical procedure is done by Taguchi Standard matrix. CNC milling is the most conventional process which is used for removing of material from workpiece to perform the needed shapes. The results and relations indicate that the rate of feed is very important factor for modeling surface roughness. The plot of S/N ratio shows that the optimum combination of the milling factors that gives the best value of surface accuracy. The best combination of milling factors has also been predicted to minimize the surface roughness.

Investigation of CNC Milling Machining Parameters on Surface Roughness

Milling Machining is a widely accepted nontraditional machining technique used to produce parts with complex shapes and configurations. The material is removed in two stages roughing and finishing, the flat end cutter removed the unwanted part of material, then finished by end mill cutter. In milling technique, the role of machining factors such as cutting depth, spindle speed and feed has been studied using Taguchi technique to find its effectiveness on surface roughness. Practical procedure is done by Taguchi Standard matrix. CNC milling is the most conventional process which is used for removing of material from workpiece to perform the needed shapes. The results and relations indicate that the rate of feed is very important factor for modeling surface roughness. The plot of S/N ratio shows that the optimum combination of the milling factors that gives the best value of surface accuracy. The best combination of milling factors has also been predicted to minimize the surface roughness.

Experimental investigation and optimization of surface roughness in negative incremental forming

Single Point Incremental Forming (SPIF) allows the possibility of forming components of various shapes and sizes with the use of simple and economical tooling. Investigation of surface quality of the formed components becomes necessary for selecting the optimal process parameters in order to ensure precision and safe forming of the components. Moreover, lack of available knowledge regarding the process parameters makes the process limited for industrial applications. In this paper, various input factors have been investigated on the surface roughness of formed components. The process has been optimized to obtain the optimal levels of input factors for producing better surface quality using Taguchi Method (TM) as Design of Experiment (DOE) and analysis of variance (ANOVA). Results showed that the optimal experimental condition for average roughness has been determined as tool diameter (15.66 mm), tool shape (hemispherical), the viscosity of the forming oil (320 cSt), sheet thickness (0.8 mm), wall angle (60°), step size (0.2 mm), tool rotation (1000 rpm), and feed rate (1500 mm/min). The tool diameter has been found the most dominating factor for average surface roughness of the conical frustums. Tool shape and the viscosity of forming oil have also been significant factors for average roughness. The results obtained from confirmatory experiments showed that predictive model obtained from TM is efficient and effective for estimating optimal levels of input parameters for producing the better surface quality during the SPIF process.

New Approach for Unconventional Reservoirs Rock Typing Characterization: Egyptian Unconventional Gas Reservoirs

The main objective of this research is to enhance unconventional reservoir characterization by developing and/or establishing new correlations through using a real case study of unconventional shale gas reservoir called Upper Safa formation that located in the western desert of Egypt. In addition to describing its geochemical and petro physical reservoir rock and fluid properties more consistently through a full integration among unconventional rock parameters as permeability, porosity, tortuosity, surface roughness, adsorption, type of kerosene, level of maturity, total organic carbon content, and etc. The results showed that Upper Safa formation is a shale gas unconventional resource play that consists mainly of Kaolinite clay and other mixed clay types. Geochemical pyrolysis analysis is used to confirm the presents of Kerogen type III as a shale gas potential reservoir. Interpretation analysis has been used also to confirm the presence of hydrocarbon potential in shale reservoirs depend on the readings that indicating most of shale play. Hence, after applying the surface roughness factor to Total gas in place equation through multiplying the (1-0.4) factor to volume of adsorbed gas in place to get new more accurate value for total gas in place TGIP’ equals 9.12 BCF. Moreover, brittleness ratio average value equals to 50% brittleness. However, TOC results which are obtained within the ranges of very good petroleum potential according to Rock Eval pyrolysis from 2% to 4% TOC. Hence, the results obtained from using of Dykstra Parson permeability variation, Upper Safa formation is highly heterogeneous formation which is very close to 100% heterogeneous formation, as any unconventional shale reservoirs due to the huge variation in the permeability ranges from milli-Darcy ranges to nano-Darcy ranges. Thus, several conventional and unconventional rock typing methods have been applied to overcome this zonation problem, besides establishing a new approach for unconventional reservoirs rock typing.

Pore-scale numerical investigation of the impacts of surface roughness: Upscaling of reaction rates in rough fractures

The roughness of solid surfaces influences mineral dissolution rates by affecting flow and transport in the near-surface regions and by increasing the surface area available for reaction. The impact of surface area is commonly accounted for by using the surface roughness factor (SRF), which is the ratio between the total surface area and the nominal or geometric surface area. The coupled impacts of hydrodynamics and transport, however, are rarely considered. In this study, we performed pore-scale reactive transport simulations in a series of synthetic 2D rough fractures to investigate the compound effects of surface roughness on the reaction rates in fractures. Simulation results show that while reaction rates increase with SRF, the increase is not linearly proportional to that of the surface area. Rather, local concentration gradients resulting from flow and transport processes limit the increase in the rate. In addition, surface roughness gives rise to concentration gradients that do not otherwise develop in the flat-surface geometries typically considered in modeling studies. To describe the impacts of the surface area increase on reaction rate at different roughness and flow velocities, three distinct regimes were identified. A unified mathematical relationship was also developed that allows the reaction rate in a rough fracture to be approximated by the well-mixed reactor reaction rate and a correction factor. The correction factor follows a power-law function of SRF, with the multiplying factor and exponent expressed as exponential functions of the Péclet and Damköhler number. This mathematical formulation provides a valuable upscaling approach for effective integration of sub-grid scale surface roughness in larger scale continuum models.

Effect of Morphology and Crystal Structure on the Thermal Conductivity of Titania Nanotubes

Titania nanotubes (TNTs) with different morphology and crystal structure are prepared by chemical processing and rapid breakdown anodization (RBA) methods. The nanotubes are studied in terms of thermal conductivity. The TNTs with variable wall thickness below 30 nm have significantly reduced thermal conductivity than bulk titania, due to the phonon confinement, smaller phonon mean free path, and enhanced phonon boundary scattering. The amorphous nanotubes (TNTAmor) have comparatively thicker walls than both crystalline nanotubes. The TNTAmor has a thermal conductivity of 0.98 W m−1 K−1, which is slightly less than the thermal conductivity of crystalline anatase nanotubes (TNTA; 1.07 W m−1 K−1). However, the titania nanotubes with mixed structure (TNTA,T) and the smallest dimensions have the lowest thermal conductivity of 0.75 W m−1 K−1, probably due to the phonon confinement. The experimental results are compared with the theoretical study considering the size confinement effect with different wall dimensions of TNTs and surface scattering. The results agree well with the surface roughness factor (p) of 0.26 for TNTA,T, 0.18 for TNTA, and 0.65 for TNTAmor, indicating diffusive phonon scattering and rougher surfaces for TNTA. Interestingly, the present results together with those presented in literature suggest that thermal conductivity reduction with respect to the wall thickness occurs also for the amorphous nanotubes. This is ascribed to the role of propagons in the thermal transport of disordered structures.

Morphological and Raman Study of an Anodized Tio2 Nanotubular Matrix without Presence of Nanograss, Using Graphite as Cathode

One set of TiO2 nanotubes is anodized to identify and study the time lapse of a matrix of them without presence of nanograss as a residual layer. The anodization process consists of an organic media of ethylene glycol and NH4 F salts, constant voltage for a time period from 10 to 60 minutes. All anodized samples are rinsed and annealed to 400 °C by 2 hours to obtain an anatase crystalline structure. The morphological characterization was carried out by Field Emission Scanning Electron Microscopy to verify the presence of the nanotubes and calculate the surface roughness factor and film porosity. It was observed that roughness factor and porosity doesn’t have important variations, as time function, except for 60 minutes where nanograss has a strong presence and the gaps between nanotubes are minimal. Raman Spectroscopy was used for optical characterization in order to identify the changes in signal intensity and Eg mode Shift associated with anodization time. It was observed that intensity suffers an increment and Eg mode Shift suffers a decrement as thickness function (anodization time).

Nickel-cobalt-oxide cathodes for hydrogen production by water electrolysis in acidic and alkaline media

Mixed NiCo-oxide cathodes of various compositions were fabricated by a thermal-decomposition method and used as electrocatalysts for hydrogen production by water electrolysis in acidic and alkaline media. The oxide electrodes were found to be of a semi-crystalline structure, yielding the surface morphology characterized by a surface roughness factor going up to 25. Linear potentiodynamic and potentiostatic electrochemical measurements revealed that the Volmer reaction step controlled the kinetics of the hydrogen evolution on all the NiCo-oxide cathodes, and also on the pure metal Ni electrode (control). The Ni0.2Co0.8-oxide was identified as the best electrode material candidate among the investigated metal oxides, which was linked to the surface-area effect. However, its intrinsic activity was found to be lower than that of pure metallic Ni. Nevertheless, the Ni0.2Co0.8-oxide electrode showed a significantly higher electrocatalytic stability (fouling/deactivation tolerance) in comparison to metallic Ni.

High-Flux CO Reduction Enabled by Three-Dimensional Nanostructured Copper Electrodes

The electrocatalysis for CO reduction is interesting for both fundamental understanding of the reaction mechanisms and deriving products of higher values for the electrochemical conversion of CO2. Hereby, we report on the development of three-dimensional (3D) Cu nanostructures as advanced electrocatalysts for CO reduction. By thermal oxidation of commercial Cu foams in air, CuO nanowires or porous structures were grown on the 3D frameworks of the foam, which were then reduced to Cu by applying a cathodic electrochemical potential. The derived 3D Cu nanostructures were demonstrated to be highly active and selective for the electroreduction of CO, achieving an improvement in CO reduction current density by a factor of 6 as compared to the 2D counterpart with similar surface roughness factors, 76% Faradaic efficiency (FE) of CO conversion, and >50% FE toward ethanol. The catalytic enhancement mechanisms were further discussed in terms of transport and surface structure effects.

Influence of denture surface roughness and host factors on dental calculi formation on dentures: a cross-sectional study

BackgroundDental calculi formation on dentures can worsen the oral cavity environment by complicating oral hygiene. However, few studies have investigated the effect of how patients use and manage their dentures, denture surface roughness, and host factors such as oral cavity dryness and saliva properties on denture cleanliness and denture dental calculi formation. Accordingly, we conducted the present survey to evaluate these factors to clarify the strength of the influence of each factor.MethodsWe enrolled 53 patients who had used dentures for at least 3 months and used a dental prosthesis that covered at least the six front teeth including the left and right mandibular canines. After staining the dentures, we divided the participants into a group that was positive for dental calculi (DCP group) and a group that was negative for dental calculi (DCN group). After removing all the stains, we evaluated the surface roughness of the dentures. A questionnaire was used to survey how the participants used and managed their dentures. Oral cavity dryness was evaluated, and resting saliva samples were collected to assess saliva properties. Correlations between the presence or absence of dental calculi and denture use and management were evaluated using a chi-square test. Correlations with denture surface roughness, oral cavity dryness, and saliva properties were evaluated using the Mann–Whitney U test. Correlations between the presence or absence of dental calculi and all factors were analyzed using multivariate analysis (quantification II).ResultsSurface roughness was significantly greater in the DCP group (p < 0.01), and the DCP group members wore their dentures during sleep significantly more often and used a denture cleaner when storing their dentures significantly less often (both p < 0.01). No significant differences were observed for oral cavity dryness or saliva properties. The multivariate analysis showed significant correlations of dental calculi formation with denture surface roughness and items related to denture use and management, but not for oral cavity dryness or saliva properties.ConclusionsOur findings indicate that dental calculi formation is influenced by how dentures are used and managed and by denture surface roughness, but not by oral cavity dryness and saliva properties.