Reduction In Roughness Research Articles

Role of Rough Neutrosophic Attribute Reduction with Deep Learning-Based Enhanced Kidney Disease Diagnosis

The kidneys have an important role in keeping blood pressure, electrolyte sense, and acid-base sense of body balance to remove toxins from our body. Malfunction is responsible for irrelevant to life-threatening diseases, along with malfunction in the other functional organs. As a result, scholars worldwide have committed to finding methods for effectively diagnosing and accurately treating chronic kidney disease. As machine learning (ML) classifier is widely deployed in the healthcare field for diagnoses, also CKD is now involved in the collection of disorders that could be predicted through the ML classifier. Neutrosophic logic (NL) can be employed as a form of logic that expands classical, fuzzy, and intuitionistic fuzzy logic (IF) by integrating a third constituent: indeterminacy. It enables data handling and representation with three dissimilar membership functions: truth (T), indeterminacy (I), and false (F). The complete set is independent and may differ in the interval [0, 1], providing a convoluted strategy to handle, data incompleteness, vagueness and uncertainty. This makes NL especially relevant in complicated systems where data might be partially unknown, ambiguous, or inconsistent. This article employs a Rough Neutrosophic Attribute Reduction with Deep Learning based Enhanced Kidney Disease Diagnosis (RNSAR-DLKDD) technique. Initially, the RNSAR-DLKDD technique reduces the attributes via the RNSAR technique. Followed by, the detection and classification of kidney disease take place using long short-term memory (LSTM) model. Finally, the hyperparameter selection process is carried out via crow search algorithm (CSA). To highlight the performance of the RNSAR-DLKDD technique, a series of experiments were involved. The extensive results inferred the betterment of the RNSAR-DLKDD technique over other models

Surface modification of AISI 316L stainless steel by applying single and multilayer coatings: Study of elastic modulus and antibacterial properties.

AISI 316L stainless steel is extensively used in various fields, including medicine. In this study, in order to improve antibacterial properties, reduce elastic modulus, increase hydrophilicity and delay corrosion on the surface of AISI 316L stainless steel pieces for biomedical applications, zinc and magnesium elements were used for coating. Zn monolayer, Zn-Mg bilayer, and Zn-Mg-Zn triple coatings were deposited on AISI 316L substrates using the thermal evaporation method. Field emission scanning electron microscopy (FE-SEM) confirmed the formation of thin film coatings on the substrate. EDX analysis also indicated the presence of Zn and Mg elements in the coatings. Atomic force microscopy (AFM) results showed a reduction in the root mean square roughness in the coated specimens compared to the uncoated ones. This technique was also used to compare the force between the samples. The result of this research indicated 22.78% increase in hydrophilicity, 31.25% improvement in antibacterial properties and 86.67% reduction in elastic modulus when comparing the uncoated sample with the three-layer coated sample. X-ray diffraction (XRD) revealed the intermetallic composition of Zn and Mg. The average crystallite size, determined using Scherer's equation, was 14.61, 13.15, 13.92, and 49.60nm for the uncoated, one-layer, two-layer, and three-layer samples, respectively. Atomic absorption spectroscopy (AAS) revealed that the 24-h release of Zn2+, Mg2+, and Ni2+ ions from the samples was within the allowable range when immersed in simulated body fluid (SBF). Corrosion measurements indicated the formation of a galvanic cell due to the layers in the coated samples, and the substrate did not corrode until the coating was fully degraded.

Adaptive Control of Pressure Difference in Abrasive Flow Machining for Inner Hole with High Depth/Diameter Ratio.

To address the issue of uneven pressure distribution in the abrasive flow field within the inner hole of components with a large depth/diameter ratio, an adaptive control strategy for regulating flow field pressure difference is proposed in this paper. The strategy was based on the effects of pressure fluctuations at the abrasive flow inlet and outlet on pressure distribution patterns and pressure changes within the inner hole flow field, as derived from numerical simulations. An adaptive control fixture was also designed, enabling dynamic adjustments to the fixture gap, which significantly reduced the pressure difference in the flow field. Experimental results demonstrated that the surface texture uniformity of the inner hole was greatly improved after adaptive control. The non-uniformity in surface roughness after control was 59.1% lower compared to pre-control conditions, indicating improved machining consistency. Furthermore, the maximum reduction in surface roughness increased from 1.146 μm to 1.844 μm, and processing efficiency was notably enhanced.

Improving Surface Finish of Laser Additively Manufactured Curvilinear Surfaces Via Electropolishing and Electroless Coating

Abstract Laser-directed energy deposition (LDED) is a very useful additive manufacturing technique for repairing and manufacturing complex-shaped parts compared to traditional manufacturing techniques. However, the inadequate surface quality of the LDED fabricated components limits their direct utilization in different sectors. In addition, improving the surface finish of the curvilinear surfaces (useful for cooling channels and fuel nozzles) is also challenging. Hence, the current study focuses on surface modification of LDED fabricated SS 316L hollow cylindrical samples by combining electropolishing and electroless coating. We have performed electropolishing (two different currents, 8 A and 15 A) on the as-deposited (AD) sample with and without the application of the grinding process. The electropolishing reduced the roughness of the AD sample from 3.2 µm to 0.85 µm and 0.74 µm for 8 A and 15 A, respectively. The reduction in roughness was more at a higher current value due to the rapid anodic dissolution of the surface peaks. A further reduction in roughness was observed when grinding was performed before electropolishing. However, grinding resulted in higher material removal from the deposited surfaces and reduction in roughness was also minimal. Hence, only the electropolishing sample was selected for the next step, in which Ni-P electroless coating was performed on the surface to form a protective layer. After electroless coating, the coefficient of friction and wear-rate were reduced by 9.5% and 25.6% compared to the AD sample. Delamination and severe plastic deformation were the major wear mechanisms for the AD sample, whereas abrasion was dominant for the coated sample. The current work proposes a combined surface modification approach of electropolishing and electroless coating for the LDED processed components with curvilinear surfaces.

Optimization of sustainable polymer composites for surface metamorphosis in FDM processes

The demand for the development of sustainable manufacturing processes is enhanced by the necessity to optimize polymer composites, particularly in the context of fused deposition modeling (FDM). This research aims to enhance sustainable polymer composites to improve the surface metamorphosis during FDM processes. Various eco-friendly polymer matrices were integrated with novel composite reinforcements to evaluate their impact on surface quality, structural integrity, and the performance of FDM-printed components. Key surface features, including roughness (Ra), texture, and function, were quantified through both experimental and computational methods. The optimized composites led to a significant reduction in surface roughness, with Ra values improving by up to 45% compared to standard filaments. In addition, tensile strength was increased by 30% and flexural strength by 20% relative to unmodified polymer composites. Optimization strategies, guided by green chemistry principles and materials science, successfully enhanced surface finishes and functional properties, aligning with sustainability goals. The results demonstrate that optimized sustainable polymer composites can significantly improve the quality and performance of FDM prints, supporting more efficient and environmentally friendly manufacturing practices. This study contributes to advancing materials and processes in line with sustainability principles and surface engineering.

Evolution of the liquid/solid interface roughness in Si1-xGex layers processed by nanosecond laser annealing

Pulsed laser annealing is a relevant alternative to conventional thermal processes for future technology nodes as it enables the application of a fast and local thermal budget. Such high-energy process can lead to the formation of a liquid phase that recrystallizes upon heat dissipation, through a high velocity liquid/solid interface moving towards the surface. Here, we report on the evolution of the liquid/solid interface roughness and its influence on the crystallinity of Si1-xGex layers depending on multiple parameters (strain state, doping level, Ge content, and pulse duration). This has been conducted with a roughness quantification method based on cross-section STEM-HAADF micrographs. It has been established that the liquid/solid roughness can be decreased by: (i) a compressive strain decrease, (ii) the use of short duration laser pulses or (iii) a reduction of the initial Ge content. The Ge content and strain must correspond to suitable values for optimized MOSFET performances. Consequently, strain and pulse duration were found to be pertinent levers for liquid/solid interface roughness reduction. Increasing the amount of boron atoms in s-Si1-xGex:B/Si systems is another relevant strategy, as compressive strain decrease would then be associated with a beneficial contact resistance lowering in the source-drain regions of p-type MOSFET devices.

Insights Into the Effects and Implications of Acidic Beverages on Resin Composite Materials in Dental Restorations: An InVitro Study.

Dental composite resins are commonly used due to their excellent physical and mechanical properties. However, exposure to beverages like Coca-Cola, Apple juice, and Black coffee can negatively impact these materials. This study examined the effects of these drinks on the surface microhardness and surface roughness of Nanohybrid, Giomer, and Dual-Cure Bulk-fill resin composites. Seventy-two disc-shaped resin composite specimens were prepared and divided into four groups (n = 18) based on immersion liquid: Group 1 (Coca-Cola), Group 2 (Apple juice), Group 3 (Black coffee), and Group 4 (Distilled water). The composites were further categorized into NeoSpectra (Subgroup 1), Beautifil II (Subgroup 2), and Predicta (Subgroup 3). Specimens were immersed for 14 days, alternating 18 h in beverages and 6 h in distilled water daily. Microhardness was measured using a Vickers microhardness tester, and surface roughness was analyzed by atomic force microscopy. Data were assessed using one-way ANOVA and Tukey's post hoc test, with significance set at p < 0.05. All groups experienced significant decrease in microhardness and surface roughness. Coca-Cola led to the highest roughness and hardness reduction. Among composites, the Nanohybrid resin (NeoSpectra) showed the least alteration. NeoSpectra ST, a nanohybrid composite, demonstrated superior resistance to acidic beverages compared to Giomer and Bulk-fill composites. The study finds that out of three composite materials, nanohybrid composites are the most acid resistant which provides a suitable material for patients who consume acidic beverages more frequently. In this way, clinicians can use this information to help optimally increase the longevity of their restorations by selecting materials according to oral exposure levels of acids in their patients.

New Composite Materials Based on PVA, PVP, CS, and PDA.

In this work, new materials based on the blends of polyvinyl alcohol (PVA), polyvinyl pyrrolidone (PVP), chitosan (CS), and polydopamine (PDA) have been prepared. Fourier Transform Infrared Spectra have been conducted to verify the presence of individual components in the composite materials. EDX elemental analysis showed a clear view of the element's presence in the composite materials, with the maximum values for carbon and oxygen. Atomic force microscopy (AFM) was used to observe the surface topography and measure the surface roughness. In the case of the individual polymers, CS presented the higher value of surface roughness (Rq = 3.92 nm and Ra = 3.02 nm), and surface roughness was found to be the lowest in the case of polyvinyl pyrrolidone (PVP), and it was with values (Rq = 2.34 nm and Ra = 0.95 nm). PVA films presented the surface roughness, which was with the value (Rq = 3.38 nm and Ra = 2.11 nm). In the case of composites, surface roughness was highest for the composite based on PVA, PVP, and CS, which presented the value (Rq = 11.91 nm and Ra = 8.71 nm). After the addition of polydopamine to the polymeric composite of PVA, PVP, and CS, a reduction in the surface roughness was observed (Rq = 7.49 nm and Ra = 5.15 nm). The surface roughness for composite materials was higher than that of the individual polymers. The addition of PDA to polymeric composite (PVA/PVP/CS) led to a decrease in Young's modulus. The elongation percentage of the polymeric films based on the PVA/PVP/CS/PDA blend was higher than that of the blend without PDA (9.80% vs. 5.68% for the polymeric composite PVA/PVP/CS). The surface of polymeric films was hydrophilic. The results from the MTT assay showed that all tested specimens are non-toxic, and it was manifested by a significant increase in the viability of L929 cells compared with control cells. However, additional studies are required to check the biocompatibility of tested samples.

Reduction of surface roughness in selectively etched microchannels in lithium niobate

By post-etching annealing, the roughness of microchannels fabricated by fs laser assisted selective etching could be reduced to values of 2 nm. The influence of inscription parameters and annealing conditions on the microchannels’ roughness and the evolution of their shape with annealing temperature and time have been investigated. A functional dependence enabling the estimation of roughness values resulting from certain processing parameters was determined. The low surface roughness achieved enables the transport of fluids with very low friction factors and optical-grade surfaces for the combination of microfluidic channels with optical waveguides, allowing the acousto-optical, electro-optical, and (nonlinear) optical properties of lithium niobate to be utilized for future monolithic optofluidic devices.

Polyimide passivation‐enabled high‐work function graphene transparent electrode for organic light‐emitting diodes with enhanced reliability

AbstractChemical vapor deposition (CVD)‐gown graphene has tremendous potential as a transparent electrode for the next generation of flexible optoelectronics such as organic light‐emitting diodes (OLEDs). A semiconductor coating is critical to improve the work function but usually makes graphene rougher and more conductive, which increases leakage, and then significantly restrict device efficiency improvement and worsens reliability. Here an insulating polyimide bearing carbazole‐substituted triphenylamine units and bis(trifluoromethyl)phenyl groups (CzTPA PI/2CF3) with high thermal stability is synthesized to passivate graphene. The similar surface free energy allows the uniform coating of CzTPA PI/2CF3/N‐methylpyrrolidone on graphene. Despite of a slight decrease in conductivity, CzTPA PI/2CF3 passivation enables a substantial reduction in surface roughness and improvement in work function. By using such CzTPA PI/2CF3‐passivated graphene as anode, a flexible green OLED is demonstrated with a maximum current, power, and external quantum efficiencies of 88.4 cd A−1, 115.7 lm W−1, and 24.8%, respectively, which are among the best of the reported results. Moreover, the CzTPA PI/2CF3 passivation enhances the device reliability with extending half‐life and reducing dispersion coefficient of efficiency. The study promotes the practical use of graphene transparent electrodes for flexible optoelectronics.image

Alumina-enriched sunflower bio-oil in machining of Hastelloy C-276: a fuzzy Mamdani model-aided sustainable manufacturing paradigm

With the increasing emphasis on sustainable manufacturing practices, eco-friendly lubricants have gained significant attention to moderate the friction coefficient at the tool-work interface. In line with this, the contemporary study aimed to examine the viability of Alumina-enriched sunflower bio-oil as a metalworking fluid. Different volume fractions of Alumina nanoparticles (varying from 0 to 1 vol%) were mixed with sunflower bio-oil, and the physical properties, for instance, contact angle and dynamic viscosity, were analyzed to determine the optimal concentration of Alumina. Subsequently, machining experiments were executed on Hastelloy C-276 under various lubricating conditions, including dry cutting, compressed air, sunflower bio-oil, and 0.6 vol% Alumina-sunflower bio-oil. A comparative analysis among these lubricating mediums demonstrated that sunflower bio-oil with a 0.6 vol% Alumina concentration outperformed others, resulting in a significant reduction of surface roughness, and tool wear by 73.31%, and 82.14% respectively when compared to dry machining. Besides, the utilization of 0.6 vol% Alumina-sunflower bio-oil has demonstrated a reduction of 17.86% in total machining cost, along with reductions of 15.44% in energy consumption and carbon emissions, when compared to dry machining. Finally, a Taguchi-designed experiment consisting of sixteen trials was performed in different lubricating conditions, and a Fuzzy-Mamdani model was employed to achieve a sustainable machining environment. The sustainability assessment results indicated that a cutting speed of 75 m/min, feed of 0.05 mm/tooth, depth of cut of 0.15 mm, and the utilization of the 0.6 vol% Alumina-sunflower bio-oil resulted in the most sustainable machining environment, with the highest Multi-Performance Characteristics Index of 0.75.

Use of Pulsed Potentials for Electropolishing TA6V Parts Elaborated By Additive Manufacturing in Deep Eutectic Solvent

It is now possible to achieve complex geometries by additive manufacturing of various metals and alloys, without compromising their core mechanical and structural properties. Nevertheless, their degraded surface state remains a critical issue which constitutes a key obstacle for its broad deployment. SLM parts are characterized by their high roughness (Ra up to 40 µm), a strong texture (directly related to the manufacturing process and parameters) and to the presence of potentially detachable unmelted particles. For almost all applications, relevant finishing post-treatments must be carried-out on the surface, to improve its behavior against fatigue, ageing, corrosion and abrasion. Due to oxygen contamination of the surface, titanium and titanium alloys have the ability to form an oxide layer at its surface, called alpha case. In addition to a high hardness which makes the part difficult to machine, this layer alters the mechanical properties (such as loss of ductility, degradation of static and fatigue strength) and corrosion resistance. The degradation of the properties caused by the formation of this layer forces manufacturers to carry out additional operations such as chemical attack, machining, sandblasting, ...etc. Removal of alpha case by chemical polishing is often done with fluorine ions, which creates soluble complex with titanium leading to mass loss, with the drawbacks linked to this kind of processes.Electropolishing then becomes an interesting alternative, especially if it is carried out in an electrolyte presenting a low health hazard such as Deep Eutectic Solvent (DES). This kind of solvent, used for the first time by Abbott et al [1], are more tolerant to water and less expensive than Room Temperature Ionic Liquids. Pure metallic titanium plates were also successfully electropolished in a DES mixture made of choline chloride-propylene glycol, improving the brightness of the sample and a reduction of the roughness from a few hundreds of nanometers to about 40 nm [2]. The problem is however very different considering additively manufactured parts which show very high roughness (going up to several dozen µm), which leads to the risk of deformation of the geometry of the parts due to very long processing times. In addition, the very high natural viscosity of the electrolyte, combined with the formation of a viscous layer on its surface, creates fluid movements. Indeed, when it reaches too much thickness, the viscous layer detaches itself to flow, which has the effect of creating inhomogeneities on the removal of matter and the reduction of roughness. To overcome this problem, the use of pulsed potentials cycles, at two frequencies, was evaluated. The first one based on short pulses, already experienced on stainless steel, aims to limit the geometric deformation during long processing time [3]. The second one, based on longer pulses allow to limit the growth of the viscous layer and prevent its flow. These sequences were designed through the study of transient curves, and were applied to test pieces on RDE electrodes, leading to bright and homogeneous titanium alloy samples. This process was implemented into a 65L tank, were different parts were successfully finished.[1] A.P. Abbott; G. Capper; K.J. McKenzie; A. Glidle; K.S. Ryder; “Electropolishing of stainless steels in a choline chloride based ionic liquid: an electrochemical study with surface characterisation using SEM and atomic force microscopy” Phys. Chem. Chem. Phys., 8 (2006), pp. 4214-4221[2] A. Kityk; V. Protsenko; F. Danilov; V. Pavlik; M. Hnatko; J. Šoltýs; “Enhancement of the surface characteristics of Ti-based biomedical alloy by electropolishing in environmentally friendly deep eutectic solvent (Ethaline); Colloids and Surfaces A: Physicochemical and Engineering Aspects, 613 - (2021), pp126125[3] M. L. Doche; J-Y Hihn; E. Drynski, F. Roy; A. Boucher; Jason Rolet; J. Tardelli; “Electropolishing of 316L stainless steel parts elaborated by selective laser melting: from laboratory to pilot scale,” Procedia CIRP, vol. 108, no. C, pp. 722–727, 2022

Low-Temperature Ozone Atomic-Level Trimming on Ge Interfused Channel with Subthreshold Characterization Enhancement for Gate-All-Around Si Nsstransistors

Recently, stacked nanowire/nanosheet GAAFETs have been under intensive investigation owing to their excellent electrostatics and short-channel control, which can fulfill the requirement of the 5-nm technology node and beyond. However，GAAFETs are affected by the overall thermal budget of the integration process, and after channel release removes the SiGe stack, the presence of Ge residues on the Si channel surface increases the interfacial trap charge, leading to increased defects on the channel surface, which affects the subthreshold characteristics of the device and increases the SS. Due to the tendency to overcorrode during the channel release process and the effect of Ge diffusion, the NS surface roughness becomes larger, leading to enhanced surface scattering and resulting in a decrease in the effective mobility of the carriers, in which the surface roughness change mainly affects the surface roughness scattering and Coulomb scattering of the carriers. Conventional interface treatment methods cannot accomplish the reduction of SS and surface roughness at the same time, so in this paper, we propose a low-temperature ozone atomic-level stripping process method to thin the trench of the gate-all-around NS device. Removing Ge diffused into the trench due to the thermal budget, reducing the trench surface roughness and the surface state, and repairing the free Si and Ge bonds caused by the high thermal budget and the diffusion of Ge. Finally, the device subthreshold characteristics are optimized.In this paper, the verification is first carried out on capacitor wafers by using low temperature ozone atomic level stripping treatment on silicon wafers with simulated channel surfaces for 1/2/5 times, respectively. After O3 treatment, the interface state density is significantly reduced, the interface optimization results results are shown in Fig1. At the same time the above operation makes the thickness of the oxide layer reduce significantly, the EOT is reduced, resulting in a lower K value. So two O3 treatments are applied to the channel surface after channel release in the actual device. The result SS is reduced from 67.5 to 64.3 mV/dec for PFET and reduced from 67.8 to 64.8 mV/dec for NFET (Fig. 2), the device characteristics are significantly improved.N-type MOSCAPs were fabricated with the standard high-k/metal-gate (HK/MG) on a Si0.7Ge0.3 epitaxy layer on p-type bulk-Si (100) wafers. The process flows and key process-step techniques are shown. To reflect the channel interface issues of GAA NSFETs, the capacitors were fabricated on the epitaxy substrate with at a rapid thermal annealing (RTA) and a simulated channel release process. Firstly, 12 nm Si and 18 nm Si0.7Ge0.3 were epitaxially grown on the substrate as the channel surface, and an RTA of 850 ℃ for 75s was performed based on the general thermal budget requirement of the front-end process. Next, the SiGe layer was removed by channel release solution. Afterwards, the substrate was processed by O3 for 2 second after wet-etch SiGe 20s, and then rinsed in DHF for 20s to remove the oxidation. Figure 1

Electropolishing to Surface Finish of Hastelloy X Manufactured By Laser Powder Bed Fusion

Laser Powder Bed Fusion (LPBF) is a metal additive manufacturing technology (AM) that uses high power laser to melt powder layer by layer to create mechanical parts. LPBF several advantages, including short manufacturing time, freedom to design complex geometries and user-friendly customization. It is widely used in the manufacture of high-value parts in aerospace, automotive and biomedical industries. Due to the nature of the layer-by-layer process, partially melted powder is attached to the as-built part surface during LPBF, resulting in a significant increase in surface roughness. Furthermore, initial surface roughness of final part is different with locations since quantity of powder adhesion varies depending on building angle. Increase of surface roughness due to attached metal powder can cause out of dimensional tolerance that designed. Such dimensional inaccuracy can lead to failure or breakage of the mechanical parts. Therefore, surface post-treatment is essential to reduce surface roughness with minimizing dimensional change. Conventional mechanical and chemical treatments for surface finishing have limitations such as limited tooling range and surface damage due to the use of strong acids and long-time of processing. Electropolishing, based on electrochemical reactions, is suitable for improving the roughness of LPBF manufactured parts with complex geometries. Thickness reduction can be predicted by controlling the applied voltage and processing time. Also, surfaces in contact with the electrolyte is polished without geometric restrictions. Studies have been reported that analyze the change in surface roughness after electropolishing to improve the roughness of alloys manufactured with LPBF. However, for application to real parts, it is necessary to conduct basic research to optimize the electropolishing conditions to obtain satisfactory surface roughness with minimal thickness reduction by considering the effect of dimensional changes during electropolishing. In this study, we electropolished Hastelloy X fabricated by LPBF. Four types of electrolytes were selected for electropolishing. We measured surface roughness and thickness reduction with respect to applied voltage and processing time. With such results, optimized condition to reduce the surface roughness with minimal thickness changes are discussed. Then, these conditions were applied to LPBF specimen with different building angles. Surface roughness and weight changes were measured to compare polishing efficiency to each electrolyte.

Gold and Gold Alloys Electropolishing in Choline Chloride-Glycerol Deep Eutectic Solvents

Electropolishing is a finishing technique used to reduce the roughness of metallic surfaces while enhancing their brightness. Based on anodic dissolution, this process enables the treatment of parts with complex geometries and reduces processing time compared to conventional mechanical finishing methods.Concerning precious metals, the use of electrolytes containing cyanides and other toxic compounds reduces EP’s attractiveness from an industrial standpoint. A further challenge lies in the difficulty of dissolving alloy elements in a homogeneous way1. It often requires the adjustment of operating parameters or even of the electrolyte composition for each alloy. In addition, the underlying mechanisms that govern the process are not fully understood, making it more difficult to scale up. As a result, it has become essential to explore high-performance electrolyte solutions while complying with environmental and health safety standards.Deep Eutectic Solvents (DES) are emerging as a good alternative for the chemical2 and electrochemical3 dissolution of metals. Their advantages include an extended electrochemical window compared with aqueous electrolytes, non-toxicity, and moderate cost3,4. They have already demonstrated their effectiveness on a wide selection of metals, including silver5 and copper3, elements often present in gold alloys.This work aims to evaluate the effectiveness of choline chloride-based DESs in the electropolishing process of 18K gold alloys. Their performance will be assessed in terms of roughness reduction, brightness enhancement and color preservation, all characteristics associated with the presence of uniform dissolution. The electrochemical mechanisms involved will also be examined.(1) Rodriguez J. ; Doche M-L ; Hihn J-Y ; Electropolishing of gold and gold alloys in HCl-glycerol-ethanol electrolytes App. Surf. Sci. Adv. 21(2024) 100604 https://doi.org/10.1016/j.apsadv.2024.100604(2) Jenkin, G. R. T.; Al-Bassam, A. Z. M.; Harris, R. C.; Abbott, A. P.; Smith, D. J.; Holwell, D. A.; Chapman, R. J.; Stanley, C. J. The Application of Deep Eutectic Solvent Ionic Liquids for Environmentally-Friendly Dissolution and Recovery of Precious Metals. Miner. Eng. 2016, 87, 18–24. https://doi.org/10.1016/j.mineng.2015.09.026.(3) Lebedeva, O. Metals | Free Full-Text | Advantages of Electrochemical Polishing of Metals and Alloys in Ionic Liquids. Metals 2021. https://doi.org/10.3390/met11060959.(4) Sánchez-Ortiz, W.; Aldana-González, J.; Manh, T. L.; Romero-Romo, M.; Mejía-Caballero, I.; Ramírez-Silva, M. T.; Arce-Estrada, E. M.; Mugica-Álvarez, V.; Palomar-Pardavé, M. A Deep Eutectic Solvent as Leaching Agent and Electrolytic Bath for Silver Recovery from Spent Silver Oxide Batteries. J. Electrochem. Soc. 2021, 168 (1), 016508. https://doi.org/10.1149/1945-7111/abdb01.(5) Loftis, J. D.; Abdel-Fattah, T. M. Nanoscale Electropolishing of High-Purity Silver with a Deep Eutectic Solvent. Colloids Surf. Physicochem. Eng. Asp. 2016, 511, 113–119. https://doi.org/10.1016/j.colsurfa.2016.09.013. Figure 1

Modeling &amp; optimization of Ti6Al4V turning for sustainable shearing considering rake angle

Titanium alloys, such as Ti6Al4V, have become increasingly prevalent in aerospace and biomedical industries owing to their exceptional mechanical properties and corrosion resistance. However, the machining of these alloys presents significant challenges including high tool wear, poor surface finish, and low productivity. This study focused on enhancing the machinability of Ti6Al4V during CNC turning using the Taguchi optimization method. This approach aims to identify the optimal cutting parameters that minimize the surface roughness, flank wear, and crater wear, thereby improving the overall machining performance. This study systematically investigated the influence of various cutting parameters on machining outcomes. The experimental results demonstrate that the Taguchi method effectively determines the optimal process parameters, leading to a significant reduction in surface roughness and tool wear. These findings highlight the potential of the Taguchi optimization technique for achieving improved machinability and sustainability in the machining of Ti6Al4V.

Agricultural waste valorisation – Novel Areca catechu L. residue blended with PVA-Chitosan for removal of chromium (VI) from water – Characterization, kinetics, and isotherm studies

Arecanut, an industrial crop prevalent in tropical regions such as India, Sri Lanka, and parts of Southeast Asia, generates significant agricultural waste during processing. This study explores a waste-to-wealth approach by incorporating arecanut organic residue into Polyvinyl alcohol (PVA) - Chitosan blends via an eco-friendly continuous stirring method to develop an adsorbent film for removing chromium (VI) from water. Morphological analyses confirmed enhanced surface area, porosity, and roughness in the blended films. XRD and FTIR analyses indicated a semi-crystalline nature with a decrease in the characteristic peak intensity of PVA and chitosan, confirming the incorporation of arecanut residue. Optimal conditions identified OR-4 film, using 0.4 g of adsorbent, achieving 88.68 % removal of 173 mg/L chromium (VI) at pH 9.0, within 45 minutes at 40°C. SEM images demonstrated significant surface roughness reduction before and after adsorption, confirming chromium adsorption. Kinetic studies revealed a pseudo-second-order model and adsorption isotherms confirmed film surface heterogeneity. This research advances eco-friendly materials for water purification and offers a sustainable solution for managing agricultural residues.

Inductively Coupled Plasma Reactive Ion Etching of (−201) β‐Ga2O3 Nano‐Fins

This study reports the effect of inductively coupled plasma reactive ion etching using a BCl3/Ar gas mixture on the sidewall taper angle (STA), etch rate, and surface morphology of (−201) β‐Ga2O3 substrates, as well as (−201)‐oriented β‐Ga2O3 films on sapphire, for nano‐fins of ≈200 nm width. Various etch parameters are systematically investigated for the β‐Ga2O3 films on sapphire, revealing that the STA is lower at high plasma density when chemical component increases, and the ion scattering decreases; achieving a STA of 1.5° ± 0.7°, accompanied by an etch rate of 114 nm min−1 and a reduction in surface roughness compared to before etching. Additionally, a strong positive correlation between the STA and the crystal orientation in the β‐Ga2O3 substrates is observed at lower plasma density, while a weak correlation is found between the STA and the crystal orientation at high plasma density. This study provides valuable insights for the fabrication of β‐Ga2O3 devices.

An Experimental Investigation into the Enhancement of Surface Quality of Inconel 718 Through Axial Ultrasonic Vibration-Assisted Grinding in Dry and MQL Environments

Ultrasonic vibration-assisted grinding (UVAG) has proven to be beneficial for grinding difficult-to-machine materials. This work attempts to enhance the grinding performance of Inconel 718 through a comprehensive study of UVAG characteristics. Grinding experiments were performed in both dry and Minimum Quantity Lubrication (MQL) environments, and assessment of the grinding forces, specific energy, residual stress, and surface topography was done. A substantial reduction of both surface roughness and grinding force components was observed in UVAG compared to conventional grinding (CG). Utilizing UVAG with MQL at the maximum vibration amplitude led to a 64% reduction in tangential grinding force and a 51% decrease in roughness parameter, Ra, when compared to CG conducted in a dry environment. The high-frequency indentations of the abrasives in UVAG generated compressive residual stresses on the ground surface. Surface parameters pointed to uniform texture and SEM images showed widening of abrasive grain tracks on the workpiece surface during UVAG. The utilization of UVAG under MQL produced a synergistic impact and resulted in the lowest grinding forces, specific energy, and optimal surface quality among all the grinding conditions investigated. Overall analysis of the results indicated that the axial configuration of the vibration set-up is favorable for UVAG, and the high-frequency periodic separation-cutting characteristic of the process improves lubricating efficiency and grinding performance.

Electrophoretic deposition of bioactive glass 58S- xSi3N4 (0 < x < 20 wt.%) nanocomposite coating on AISI 316L stainless steel substrate for biomedical applications

This paper aims to investigate the biocompatibility, bioactivity and properties of bioactive glass 58S-xSi3N4 (0 < x < 20 wt.%) nanocomposite coating on AISI 316 L stainless steel substrate, applied by electrophoretic deposition method. The implications of adding Si3N4 nanoparticles up to 20 wt.% to the bioactive glass coating for the structural and biomedical properties of deposited coatings were investigated. The deposited coating samples were characterized by X-ray diffraction (XRD) analysis, field emission scanning electron microscope (FE-SEM), Fourier-transform infrared spectroscopy (FTIR), and energy dispersive X-ray spectroscopy (EDS). For the evaluation of cellular toxicity, the MTT cytotoxicity test with MG63 bone cell was performed. Bioactivity test was also conducted in simulated body fluid (SBF) up to 28 days. Results showed that increase in the Si3N4 content of composite samples is associated with a significant decrease in the average size of composite powder, inferring that Si3N4 additive has become nucleation sites during synthesis. Stereomicroscope images showed that with an increase in deposition time up to 70 min, a uniform coating can be attained. An increase in the Si3N4 content is associated with a significant reduction in surface roughness and non-uniformities of the deposited layer. The addition of Si3N4 in the composite layer slightly increases the wetting angle. The highest cellular toxicity was observed for the AISI 316 L sample at the concentration of 10 micromolar, while the lowest cellular toxicity is attributed to the BG-20 %Si3N4 sample at the concentration of 75 micromolar, exhibiting viability values similar to the control sample. Bioactivity assessment of deposited coatings indicated a remarkable improvement in the bone-forming ability of Si3N4-containing bioactive glass composite.