Rough Metal Surfaces Research Articles

Experimental investigation on abrasive water jet cutting of high strength aluminium 7068 alloy

This study attempts to review the impact of input process variables of abrasive water jet cutting (AWJC) such as traverse speed, abrasive feed rate, and stand-off distance (SOD) on output responses like metal removal rate (MRR) and surface roughness. The experiments were carried out on high-strength aluminium 7068 alloy using garnet 80 mesh abrasive. Few researchers attempted their investigations on aluminium 7- series alloys, and no work has been reported on high-strength aluminium 7068 alloy generally employed in aerospace applications. Taguchi's design of experiments technique was utilized to explore the influence of AWJC parameters and their relations over output responses. The optimum settings to obtain maximum MRR and lower surface roughness are determined as traverse speed = 130 mm/min, 259 mm/min; abrasive feed rate = 300 gm/min, 300 gm/min; and SOD = 4 mm, 3 mm respectively.

Thermogravimetric analysis, Rietveld refinement, and atomic force micrography of cobalt ferrite nanoparticles exposed to 100 kGy Co60 γ-rays

We have investigated the thermogravimetric temperature (TGA) of magnetic cobalt ferrite nanoparticles (CoFe2O4) synthesized using a low-temperature sol–gel technique and a gamma irradiation dose of up to 100 kGy in a gamma chamber to create lattice defects inside the crystalline structure. The Rietveld refinement was performed with the help of advanced graphical tools which leads to the in-depth identification of Bragg’s reflections belonging to the space group Fd3m by evaluating the profile factor (Rp), weighted profile factor (Rwp), and the expected R-factor (Rexp) parameter. Eventually, the topographic qualities of the samples were investigated using atomic force micrography (AFM), which focused on metal ion dispersion and surface roughness and was aided by scanning electron micrography (SEM images). The Raman spectra have shown the active modes Eg, 3T2g, and A1g near 250.53; 324.36; and 765.90 respectively. The UV–Vis spectroscopic absorption of CoFe2O4 nanoparticles was reported at ∼ 208.2 Å, and the bandgap was reported to be 3.82 eV with the help of Tauc’s plot; Kubelka-Munk function F(R). The current study presents a complete X-ray diffraction pattern (XRD) analysis that may aid in the investigation of intra-atomic and molecular defects generated by 100 kGy gamma irradiation.

Optimization of Surface Roughness and Material Removal Rate in Turning of AISI D3 Steel with Coated Carbide Inserts

The aim of this paper is to optimize the metal removal rate and surface roughness through turning on AISI D3 Steel with coated carbide inserts. As per the current market scenario, for the metal cutting industries the most important challenge in the turning process is to satisfy both requirements quality as well as high productivity in less time in order to remain competitive. Among all the different cutting processes, the turning process is one of the most applied and fundamental metal removal operations in the real manufacturing environment. This work examines the impact of machining factors like speed, depth of cut & feed on roughness and MRR of AISI D3 steel which have a hardness value of 60 HRC with coated carbide inserts. At high speed and feed rate optimum MRR was achieved and opposite to that at low feed and depth of cut optimum surface roughness was obtained. Taguchi L9 (3)3 OA has been applied for experimental design. ANOVA analysis is performed just after DOE to identify the significant factor which influences MRR and surface roughness. Among the three machining factors, depth of cut and speed has more influencing effect on roughness and the feed influences MRR. Effort was made to find optimum solution to minimize the roughness and maximize the MRR by Taguchi and ANOVA technique.

Highly Ordered Polymer Nanostructures via Solvent On-Film Annealing for Surface-Enhanced Raman Scattering.

Surface-enhanced Raman scattering (SERS) has been a useful sensing technique, in which inelastic light scattering can be significantly enhanced by absorbing molecules onto rough metal surfaces or nanoparticles. Although many methods have been developed to prepare SERS substrates, it is still highly desirable and challenging to design SERS substrates, especially with highly ordered and controlled three-dimensional (3D) structures. In this work, we develop novel SERS substrates with regular volcano-shaped polymer structures using the versatile solvent on-film annealing method. Polystyrene (PS) nanospheres are first synthesized by surfactant-free emulsion polymerization and assembled on poly(methyl methacrylate) (PMMA) films. After annealing in acetic acid vapors, PMMA chains are selectively swollen and wet the surfaces of the PS nanospheres. By selectively removing the PS nanospheres using cyclohexane, volcano-shaped PMMA films can be obtained. Compared with flat PMMA films with water contact angles of ∼74°, volcano-shaped PMMA films exhibit higher water contact angles of ∼110° due to the sharp features and rough surfaces. The volcano-shaped PMMA films are then coated with gold nanoparticles (AuNPs) as SERS substrates. Using rhodamine 6G as the probe molecules, the SERS results show that the Raman signals of the volcano-shaped PMMA/AuNP hybrid substrates are much higher than those of the pristine PMMA films and PMMA films with AuNPs. For the volcano-shaped PMMA/AuNP hybrid substrates using 400 nm PS nanospheres, a high enhancement factor (EF) value of ∼1.12 × 105 with a detection limit of 10-8 M is obtained in a short integration time of 1 s. A linear calibration line with an R2 value of 0.918 is also established, demonstrating the ability to determine the concentrations of the analytes. This work offers significant insight into developing novel SERS substrates, which is crucial for improving the detection limits of analytes.

Guiding and routing surface plasmons with transformation-invariant metamaterials

Rough metallic surfaces cause severe scattering to surface plasmon polaritons (SPPs), thereby limiting SPP transmission efficiency. Here, we propose a general scheme to design ultracompact plasmonic routers that can confine and guide SPPs on an arbitrarily shaped rough surface. Our strategy makes use of recently proposed transformation-invariant metamaterials (TIMs). To illustrate the advantages of this approach, we perform finite-element simulations, showing that the performance of the designed surface wave router is robust against the change in thickness. As a result, a λ/6 thick TIM layer can significantly suppress scattering from arbitrarily shaped metallic bumps or crevices. We also give a blueprint to implement such ultracompact surface wave routers based on periodic metal/epsilon-near-zero material stackings.

Optimization of surface roughness by design of experiment techniques during CNC milling machining

This paper explores a novel methodology for the improvement of machining boundaries of processing process with different reactions, in light of Taguchi symmetrical exhibit (OA). Trials were directed on titanium combination test examples with uncoated carbide tool. In this research paper, an effort has been made to optimize the cutting parameters in CNC milling operation through various software so that better output response can be obtained. The DOE and the Taguchi method have been used in this experimental work to obtain optimum results for the output responses such as metal removal rate and surface roughness. The analyses were planned and performed utilizing the Taguchi L9 symmetrical exhibit technique. The outcome is examined using analysis of variance (ANOVA). The optimized results are speed = 1200 rpm, feed rate = 7 mm/min, depth of cut = 4 mm and tool diameter = 10 mm produces the optimum value of surface roughness Ra = 0.73 µm. The aftereffects of this review show that the Taguchi strategy can decide the advanced qualities of boundaries in CNC processing.

Nonparametric reconstruction of the statistical properties of penetrable, isotropic randomly rough surfaces from in-plane, co-polarized light scattering data: Application to computer-generated and experimental scattering data

An approach is introduced for the non-parametric reconstruction of the statistical properties of penetrable, isotropic randomly rough surfaces from in-plane, co-polarized light scattering data. Starting from expressions within the Kirchhoff approximation for the light scattered diffusely by a two-dimensional randomly rough surface, an analytic expression for the normalized surface height correlation function is obtained as an integral over the in-plane and co-polarized scattering data with the introduction of only a couple of additional approximations. The inversion approach consists of two main steps. In the first step the surface roughness is estimated. Next, this value is used to obtain the functional form of the surface height correlation function without initially assuming any particular form for this function (non-parametric inversion). The input data used in validating this inversion approach consist of in-plane and co-polarized scattering data obtained for different forms of the correlation function by either computer simulations or by experiments for two-dimensional randomly rough dielectric or metallic surfaces. Good agreement was obtained between the correlation function and surface roughness obtained during the reconstruction and the corresponding quantities assumed when generating the input scattering data; this was the case for both dielectric and metallic surfaces, for both p- and s-polarized light, and for different polar angles of incidence. The proposed inversion approach provides an accurate, efficient, robust and contact-less method based on in-plane and co-polarized scattering data for the non-parametric characterization of the statistical properties of isotropic two-dimensional randomly rough dielectric and metallic surface.

Optimization of process parameters of aluminium 2024 – T3 joints bonded using modified epoxy resin

Joining similar and dissimilar materials using polymer bonds is common practice being followed in various sectors. The strength of these polymer bonded joints depends on process parameters like adherend thickness; adhesive layer thickness, overlap, geometric configuration of joints, materials used and surface roughness of the sheet metal. The main aim of present experimental work is to optimize process parameters of Aluminium 2024-T3 joints bonded using Epoxy resin modified with rubber powder. Three variability levels were considered for each factor selected for the present experimental work. Bondline thickness was the most significant parameter followed by surface roughness, adherend thickness and the overlap.

Development of Methodology for Characterization of Surface Roughness of Solid Metallic Surfaces Using Oil Slippage Method

Abstract The study employed the phenomenon of friction between liquid droplets and solid metallic surfaces in surface roughness analysis of engineering materials. Five samples of mild steel plate were prepared to different degrees of surface roughness by facing operation. The sample surfaces were analysed to determine the roughness parameters (mean roughness, root mean square roughness, roughness skewness, and roughness kurtosis) and friction coefficient of the surfaces. Oil droplet sliding velocity was determined using the oil slippage test. The friction coefficient of the surfaces increased with increasing roughness parameter which varied from 26.334 µm at friction coefficient = 0.63 to 13.153 µm at friction coefficient = 0.46. The results from oil slippage test showed that the sliding velocity of the oil drop decreased as the friction coefficient of samples increased. At an inclination angle of 30°, sliding velocity varied from 0.51 cm/s at friction coefficient = 0.63 to 0.92 cm/s at friction coefficient = 0.46. Some of the samples exhibited a deviation in the trend of relationship between friction coefficient and sliding velocity which resulted from the variation in peak height of roughness between the sample surfaces. Oil slippage method predicts the surface behaviours of materials based on their surface parameters.

Peening Techniques for Surface Modification: Processes, Properties, and Applications.

Surface modification methods have been applied to metals and alloys to change the surface integrity, obtain superior mechanical properties, and improve service life irrespective of the field of application. In this review paper, current state-of-the-art of peening techniques are demonstrated. More specifically, classical and advanced shot peening (SP), ultrasonic impact peening (UIP), and laser shock peening (LSP) have been discussed. The effect of these techniques on mechanical properties, such as hardness, wear resistance, fatigue life, surface roughness, and corrosion resistance of various metals and alloys, are discussed. This study also reports the comparisons, advantages, challenges, and potential applications of these processes.

Influence of Molding Conditions on Bonding Strength of Thermoset Molding Compound and Metal Interface and Material Filling Behavior into the Roughened Metal Surface by Laser

Influence of Molding Conditions on Bonding Strength of Thermoset Molding Compound and Metal Interface and Material Filling Behavior into the Roughened Metal Surface by Laser

Dual flat-spherical indentation for extracting elastic–plastic properties from rough metallic surfaces

In this work, a dual flat-spherical indentation (DFSI) technique is developed for evaluating elastic–plastic properties from rough metallic surfaces. Since indentations on rough metallic surface produce dissimilar load–displacement (P-h) curves for the same material, finite element (FE) analyses and experiments demonstrate that DFSI method, in which rough surface is flattened by flat indenter before spherical indentation, extracts reproducible P-h curves from the flattened rough surface. Optimized indentation parameters are obtained by investigating the effects of surface roughness, flat indenter diameter, indentation depth on P-h curves. This allows to employ conventional spherical indentation (SI) method for property evaluation from DFSI P-h curves. The results are in good agreement with those from ideal smooth surface, and for rough surfaces (Ra = 0~20μm) common in engineering practice, the applicability of DFSI method is verified.

Topometry of metal surfaces using reflection of polarized light

The present work proposes an optical polarization based reflection technique for determining surface roughness of metal surfaces. A linearly polarized light beam is used to illuminate the sample surface and two intensity data frames are recorded with specific orientations of an analyzer. An algorithm is developed to combine the pair of intensity data frames captured with this simple setup. Assuming that the refractive index of the sample is known and constant throughout the sample, the phase difference between the transverse electric and transverse magnetic components of the light reflected from the surface preserve the information about surface roughness in terms of local angular tilts, which is subsequently converted to axial deviations about the nominal surface.

Effect of grit-blasting on the fracture toughness of hybrid titanium-thermoplastic composite joints

The aim of this study was to determine the effect of the metal surface roughness on the mechanical performance of titanium-unidirectional C/PEKK composite joints. Various surface morphologies were obtained by grit-blasting the titanium surface using different blasting pressures. Subsequently, test coupons were manufactured by co-consolidating titanium-unidirectional C/PEKK in an autoclave. Topographical characterization of the titanium surface and evaluation of interfacial fracture toughness were carried out, in order to correlate joint mechanical performance to titanium's roughness parameters. Furthermore, crack surface analysis was conducted, by means of optical microscopy, to identify and quantify the failure mechanisms driving joint mechanical performance. Results show that rougher surfaces significantly improve the fracture toughness of the hybrid interface. For titanium surfaces with an average roughness exceeding 2.5 μm, the interfacial fracture toughness was found to be comparable to the interlaminar fracture toughness typically measured for thermoplastic composite laminates.

Exposure to the oral environment enhances the corrosion of metal orthodontic appliances caused by fluoride-containing products: Cytotoxicity, metal ion release, and surface roughness

This study aimed to evaluate the metal ion release, cytotoxicity, and surface roughness of clinically used metal orthodontic appliances after immersion in different fluoride product solutions compared with those of new appliances. Used fixed appliances were debonded from 36 patients after their treatment was done. New appliances were as-received. Each used and new group comprised 36 sets of 20 brackets and 4 tubes that were divided into 3 groups by archwire type; stainless steel, nickel-titanium, and beta-titanium. The samples in each group were divided into 3 subgroups and immersed in solutions of fluoride toothpaste, 1.23% acidulated phosphate fluoride, or artificial saliva without fluoride as a control group. The immersion times were estimated from the recommended time for using each fluoride product for 3months. The samples were then immersed in Dulbecco's Modified Eagle's Medium for 7days. The cytotoxicity test was evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay using primary gingival fibroblasts. Chromium, nickel, and iron ion release were detected using inductively coupled plasma mass spectroscopy. The surface roughness of the brackets and wires was measured by a scanning electron microscope and a noncontact optical 3-dimensional surface characterization and roughness measuring device. The data were analyzed using the paired t test and 2-way analysis of variance. Used brackets demonstrated a significantly higher ion release, surface roughness, and cytotoxicity than the new brackets. Acidulated phosphate fluoride significantly increased the ion release and surface roughness; however, it significantly decreased cell viability, especially in the titanium molybdenum subgroup. Used brackets were significantly prone to further corrosion. Acidulated phosphate fluoride gel should not be used in orthodontic patients with fixed metal appliances.

Sustainable Machining of Hastelloy in EDM Using Nanoparticle-Infused Biodegradable Dielectric Fluid

Electrical discharge machining (EDM) is the unconventional machining technique used extensively for machining difficult-to-machine materials with lower material removal rate and poor surface roughness. To overcome these drawbacks, synthetic dielectric fluid is replaced with nanoparticle-infused biodegradable dielectric fluid in the machining of Hastelloy material. This paper focusses on the machining performances of Hastelloy in EDM using various concentrations of 0.5, 1 and 1.5 wt% of nano-zirconia dispersed in biodegradable canola oil methyl ester as the dielectric medium, and these characteristics were compared with those of the synthetic dielectric medium. Based on the D-optimal design coupled with cuckoo search algorithm, machining was carried out with various dielectric fluids and their influences on the metal removal rate, surface roughness, surface morphology and surface topography in EDM studied. The results proved that the canola oil methyl ester containing 0.5 wt% of nano-zirconia (C-0.5) had provided good surface finish, better surface topography, smooth surface morphology and high metal removal rate in comparison with the other dielectric fluids used in this study.

Optimization of Machining Parameters for Turning of Aluminium Alloy-2011 using Taguchi Method

Aluminium composites are among the most normally used lightweight metallic materials as they offer different various fascinating mechanical and warm properties. They are reasonably easy to shape metals, especially in material ejection structures, for instance, machining. Aluminium composites have physical properties for good machinability, as far as (cutting apparatus life-more prominent efficiency - low explicit cutting powers.) they have high solidarity to weight proportion. Subsequently, the aluminium composite 2011 is utilized in assembling of Appliance parts and automotive trim, Fasteners and fittings cylinders and funnels. Machining activity on Al alloy 2011 are performed and cutting parameters for example feed rate, depth of cut and shaft speed have been improved for metal removal rate (MRR) and surface roughness by utilizing Taguchi method. CNC lathe machine is utilized for turning activity so as to decide metal removal rate (MRR). The primary target of the present research is to explore the impact of procedure parameters on the presentation of by and large machining procedure and on surface unpleasantness in turning activity utilizing CNC machining of Aluminium composite [Al compound 2011].

A DISCRETE ELEMENT FORMALISM FOR MODELLING WEAR PARTICLE FORMATION IN CONTACT BETWEEN SLIDING METALS

The paper describes an advanced discrete-element based mechanical model, which allows modelling contact interaction of ductile materials with taking into account fracture and surface adhesion by the cold welding mechanism. The model describes these competitive processes from a unified standpoint and uses plastic work of deformation as a criterion of both local fracture and chemical bonding of surfaces in contact spots. Using this model, we carried out a preliminary study of the formation of wear particles and wedges during the friction of rough metal surfaces and the influence of the type of forming third body (interfacial) elements on the dynamics of the friction coefficient. The qualitative difference of friction dynamics in the areas of the contact zone characterized by different degrees of mechanical confinement is shown.

The impact of surface morphology on the erosion of metallic surfaces – Modelling with the 3D Monte-Carlo code ERO2.0

• The micro-scale model for simulation of the surface roughness effect on the erosion of PFCs and transport of sputtered material implemented previously into the 3D Monte-Carlo code ERO2.0 was applied for modelling of sputtering and deposition in the JET-ILW divertor conditions (smooth Tile 5 and rough Tile 6). • Micro-scale simulations have been conducted using two different assumptions: with and without tracing of incident plasma/impurity ions near the rough surface. Tracing of incident ions near the surface forms more realistic shadowing patterns than the case when this pattern is calculated based on magnetic field lines. • Simulations without tracing of incident ions have shown that surface roughness leads to a reduction of the effective sputtering yield by up to 50% depending on surface parameters. • Simulations including tracing of incident ions near the surface have confirmed decrease of the net erosion from the rough surface of the Tile 6 in comparison to the smoother surface of the Tile 5 by up to 50%. The roughness of metallic surfaces has a vital impact on the erosion of plasma-facing materials. Roughness determines the effective sputtering yield Y eff of the facing material. The angular/energy distribution of sputtered particles, and the spatial erosion and deposition distribution. The model for simulation the effect of the surface roughness was earlier implemented into the 3D Monte-Carlo code ERO2.0 and validated using results of ion beam experiments and experiments in the linear plasma device PSI-2. In the present study the developed ERO2.0 surface morphology model was applied to the JET-ILW tungsten (W) divertor consisting of smooth bulk W and W-coated CFC components. Influence of the surface roughness on the W erosion as well as on the transport of sputtered material in conditions of inclined magnetic field was investigated. Simulation results are in a good agreement with existing experimental findings.

Optimization of Parameters for Nitronic-60 on Wire-Cut Electrical Discharge Machining using Zinc-Coated Wire

The objectives of this work are to research the effective parameters of pulse ON time; pulse OFF time; voltage & wire feed whereas machined on Nitronic-60 exploitation wire-cut discharge machining exploitation zinc-coated wire. During this work, metal removal rate, surface roughness, and kerfwidth are taken as output parameters. The experimental results planned an optimum combination of parameters that provide the utmost material removal rate, minimum surface roughness, and kerf dimension. Finally, confirmation experiments were disbursed to spot the effectiveness of the planned technique. Multivariate analysis and ANOVA are performed exploitation Response Surface Linear Model.