Reduced Surface Roughness Research Articles

Studying the performance of pressurized injection lubrication in drilling operations

ABSTRACT This study investigates the pressurized injection lubrication (PIL) technique for enhanced lubrication and cooling in drilling processes. Sustainable methods like Small Quantity Lubrication (SQL) and dry cutting often struggle with cooling efficiency and chip removal, particularly for hard-to-cut materials. Using flaxseed oil as the lubricant, this research compares PIL with SQL and dry cutting. Experimental results reveal that PIL reduces surface roughness by 26.8% and drilling thrust force by 10.7% compared to SQL at the highest feed rate. PIL also achieves low oil consumption (0.9 l/hr) and energy usage (<0.034 kWh), with a setup cost under 130 USD. Its design allows easy integration into existing machines, enhancing practicality. Finite Element Analysis (FEA) modeling was employed to predict thrust forces and residual stresses, with PIL showing the least residual stresses compared to SQL or dry drilling. These findings establish PIL as a cost-effective, sustainable solution for improving machining performance and addressing modern manufacturing challenges.

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.

Effect of hard anodizing and T6 heat treatment on the dry sliding wear behavior of AlSi10Mg fabricated by direct metal laser sintering

This paper investigated the influence of hard anodizing (HA) and T6 heat treatment (HT) on the dry sliding wear characteristics of the AlSi10Mg alloy fabricated via direct metal laser sintering (DMLS). Hard anodizing was conducted in a sulfuric acid bath at 40 V for 1000 s, while the heat treatment comprised solutionizing at 530 °C for 1 h, followed by artificial aging at 150 °C for 8 h. The tribological tests were performed using the ball-on-flat mode in a high-frequency linear reciprocating tribometer under applied loads of 5 N and 10 N. The results show that the microhardness of the HA specimen increased by 1.2 times compared to the as-built condition, while the hardness of the as-built specimen declined by 44% after T6 treatment. The hard-anodized samples exhibited a 30% enhancement in wear resistance attributable to the development of a persistent and uniform distribution of oxide layers leading to pore closure and reduced surface roughness. In contrast, the T6 heat treatment resulted in an increased pore size, roughness, and grain coarsening, as validated by SEM and XRD results. Adhesion, abrasion, and delamination were the predominant wear mechanisms in the as-built specimens under all loads. In contrast, the HA specimens featured abrasion and oxidative wear mechanisms under all loads, and the HT specimens exhibited delamination wear accompanied by crack propagation. The findings underscore the essential importance of post-treatment selection to improve the wear resistance and durability of DMLS-manufactured AlSi10Mg components for industrial use.

Thermally-assisted reformation of spray-printed polymer channel layer for improved transistor performance and device-to-device uniformity

Bulk and surface morphology of a channel layer needs to be controlled to obtain desirable electrical performance of organic transistors and circuits based on them. Although spray coating is widely used in industry for continuous production of thin films, the microscopically rough nature of the spray-printed films makes it challenging to apply in electronics. Herein, we demonstrate a simple, scalable, and general approach by combining solvent mixing and thermal annealing to improve surface flatness, and therefore device reproducibility, without additional apparatuses attached to the spraying tools. We find that a small amount (2–5 vol%) of a high-boiling-point solvent, which can dissolve the channel material only at an elevated temperature, reduces surface roughness and rearranges the internal microstructure of the channel layer via dissolution and re-solidification during heat treatment. Thermally-assisted reformation of the channels of representative polymers (P3HT and PDPP2T-TT) results in 1.5–2.1 times enhancement of charge-carrier mobility in organic electrochemical transistors compared to as-printed films. At the same time, the device-to-device variation is significantly reduced with about 4–5 times lower coefficient variation in electrical characteristics.

A comparative evaluation of green surfactant-assisted calcium phosphate (CaP) coatings developed through electrodeposition and biomimetic routes

This study compares the properties of green surfactant-assisted calcium phosphate (CaP) coatings developed on 316L stainless steel (316L SS) substrates using electrodeposition (ED) and biomimetic (BM) methods. The influence of biosurfactants (BS) on these coatings' properties, deposited through both processes, is also investigated. X-ray diffraction (XRD), scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDS), and Fourier-transform infrared spectroscopy (FTIR) confirm the presence of brushite and hydroxyapatite (HAp) in the ED coatings, while BM coatings show only HAp without BS and both brushite and HAp phases with BS. The SEM analysis reveals distinct morphologies, with BS-assisted coatings showing more organized structures. The presence of BS results in more uniform coatings in both ED and BM methods. Atomic force microscopy (AFM) analysis indicates that BM coatings are smoother than ED coatings, and BS further reduces surface roughness. The comprehensive evaluations through nanoindentation, scratch testing, and corrosion studies reveal that BS-assisted ED coatings exhibit superior hardness (H), elastic modulus (E), adhesion strength, and corrosion resistance. Cytocompatibility studies using the MTT assay demonstrate that all coatings support cell attachment and proliferation without cytotoxic effects, with BM coatings showing slightly better cell viability. This study highlights the potential of green surfactant-assisted CaP coatings developed using ED and BM methods, for improving the biocompatibility and other biological properties of 316L SS implants.

Suppression of melt flow instabilities by amplifying high-frequency melt waves in laser fusion cutting

High-frequency resonant melt waves locally increase the stability of melt flow and enhance cut flank quality. To amplify these waves along the melt flow, an acoustically tuned cutting nozzle, termed the cutting whistle, generates gas flow oscillations based on a resonant cavity. The nozzle cavity is designed for 6 mm thick sheets, causing the gas flow to oscillate at 15 kHz within the kerf, creating a uniform melt flow with synchronized oscillating melt waves. Performance evaluations on stainless steel sheets show that, compared to a standard conical nozzle, the cutting whistle reduces surface roughness across the entire cutting depth and prevents coarse structures near the upper sheet surface and at the bottom in burr-free cuts.

An in-depth study of the strengthening mechanism in wood scrimber prepared via roller-pressing impregnation technology

Wood scrimber, a new type of wood composite material, can replace nature high-quality wood. To improve the mechanical properties and dimensional stability of scrimber for wider applications, a negative pressure resin-absorption method called “roller-pressing impregnation” was developed to produce wood scrimber in this study. Compared to the properties of wood scrimber prepared using the cage impregnation method (CWS), roller-pressing impregnated wood scrimber (RWS) exhibited significantly reduced surface roughness and wettability. Moreover, the thickness and width swelling rate of RWS decreased by 26.15 % and 18.77 % respectively, while the modulus of rupture increased by 12.45 %. Microscopic observation demonstrated that the weak tissue (middle lamella and vessels) in the oriented wood fiber mats (OWFMs) were damaged during the roller-pressing process. Meanwhile, these cleaved cellular helped the resin be absorbed more uniformly into the vessel cavities by the negative pressure, which enhanced the strength of the resin bonding between cells and also strengthened the hardness and elastic modulus of the cell wall. Therefore, the dimensional stability and mechanical properties of the scrimber were successfully enhanced. The in-depth exploration of the mechanism behind the roller impregnation technology was expected to accelerate the accurate controlling of the wood scrimber properties for continuous production.

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.

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.

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.

Enhancement of positive bevel β-Ga2O3 trench MOS barrier Schottky diode by post-etching treatment

A β-Ga2O3 trench MOS barrier Schottky (TMBS) diode with a novel terminal structure of positive bevel mesa and arc bottom corners has been designed and realized in this work. O2 plasma, hydrogen fluoride (HF), and tetramethylammonium hydroxide (TMAH) are used for post-etching treatment of devices, respectively. Measurement results shows that the specific on-resistance of the three devices are nearly with the same value of 2.60 mΩ·cm2. The breakdown voltage of the devices with O2 plasma, HF, and TMAH treatments are 1280 V, 1440 V, and 1800 V, respectively. Moreover, it is worth nothing that devices treated with O2 plasma have a lower reverse leakage. In addition, the breakdown location of the device is determined to be at the β-Ga2O3 interface under the edge of the field plate by combining simulation and capacitance breakdown testing. AFM and XPS are used to analyze the surface properties of β-Ga2O3 after post-etching treatments. The results show that the TMAH treatments have the most significant effect on reducing surface roughness, and the O2 plasma treatments is the most effective in decreasing oxygen vacancies.

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.

Infrared on-site heating for material extrusion additive manufacturing of carbon fiber filled polyphenylene sulfide and its nano-graphene-reinforced alternatives

This study investigates the impact of infrared heating and annealing on the mechanical properties of carbon fiber-reinforced polyphenylene sulfide (CF-PPS) and graphene nanoplatelet (GNP)-reinforced CF-PPS composites in Material extrusion (MEX) additive manufacturing. GNP/CF-PPS composites are prepared by mechanically mixing CF-PPS plastic particles with GNP particles and subjecting them to infrared heating and annealing treatments during the three-dimensional (3D) printing process. Three-point bending tests assess the mechanical properties of the samples. The results reveal that the 0.03 wt.% GNP/CF-PPS sample, subjected to infrared heating followed by annealing, exhibits a 30% increase in bending strength compared to pure CF-PPS, demonstrating that the combined treatment significantly enhances mechanical performance. Microscopy observations using a Keyence VH7000 digital optical microscope and a scanning electron microscope (SEM) confirm that GNP addition and infrared irradiation lead to reduced surface roughness and fewer fracture cross-sectional pores. The interlayer bonding improves notably, indicating enhanced internal density and structural stability. Furthermore, differential scanning calorimetry analysis shows a 20% increase in crystallinity for heat-treated samples, contributing to better interlaminar bonding and reduced temperature gradients during printing. Finite element simulations using MATLAB and ABAQUS software corroborate these findings, demonstrating that infrared heating proves more effective than varying GNP content alone in reducing deformation, residual stress, and temperature differences during the MEX process. These results provide valuable insights into improving the mechanical properties and stability of MEX-manufactured large-dimensional composite materials through optimized thermal management.

Optimisation of laser surface ablation of alumina/GO coating on AZ31D magnesium alloy using Cuckoo Search Algorithm method

ABSTRACT Graphene oxide (GO) and alumina (Al2O3) work in concert to give magnesium alloys advantageous surface qualities and protection from adverse environments. This paper aims to investigate the effect of laser surface treatment on plasma sprayed alumina-graphene oxide (GO) coating on AZ31D magnesium alloy. Key ablation quality responses; HAZ width, surface roughness and ablation rate were correlated with laser parameters using the Response Surface Methodology and optimised using the metaheuristic Cuckoo Search Algorithm Method. Laser power significantly influenced all ablation characteristics of the composite coating. The addition of 1.5 wt% GO in the alumina coating caused a significant reduction in HAZ width (43.32%), surface roughness (25.11%) and ablation rate (76.58%) when treated with optimal combinations of laser power (8 W), scanning speed (950 mm/s) and frequency (78.2 kHz). The surface quality was characterised by smooth textures, and resolidified splats along with deep pits when ablated with lower and intermediate power whereas surfaces ablated with higher power showed debonded splats with peripheral surface destruction. While a prominent 2D peak at 16 W confirmed the presence of GO layers during high-power laser contacts, the ID/IG ratio below unity across all specimens indicated minimal defect concentrations.

Experimental investigations on ultrasonic elliptical vibration turning of SiCp/Al composites

ABSTRACT This study identifies key factors affecting SiCp/Al surface formation in ultrasonic elliptical vibration assisted turning (UEVT) and conventional turning (CT) by scratch tests, end face cutting experiments and theoretical analysis. It also evaluates cutting parameters’ effects on deformation of SiCp/Al. Experimental findings underscore theimportance of vibration effect and removal rate. At lower cutting speeds, the ironing effect results in a dense morphology during UEVT that is advantageous for enhancing both surface quality and microhardness. The high removal speed increases the particle-tool interaction, promotes the generation and propagation of cracks indeformation zone. Specifically, at a reasonable cutting speed (200 mm/min), the utilization of vibration results in a 59% reduction in surface roughness and a commendable enhancement in microhardness, coupled with a significant suppression of tool wear. The results of this study are expected to provide positive theoretical recommendations for improving the machinability of SiCp/Al in UEVT.

Characterization of the Tensile Properties and Nanoscale Phase Structures of Modified Asphalts and Their Aging Behavior.

This study focuses on exploring tensile properties and nanoscale phase structures of different modified asphalts, and their aging behavior. For this, one virgin asphalt and three modified asphalts, namely, 4% SBS-modified asphalt, 2% SBS and 20% crumb rubber (CR) composite asphalt, and 4% SBS and 2%TiO2 composite asphalt, were prepared and investigated using the force-ductility test and atomic force microscopy (AFM). Also, detailed experiments of short-term (STA) and long-term (LTA) aging were conducted to obtain aged asphalt specimens. The results showed that a ductile fracture was found for the three modified asphalts. However, for the activation energy, SBS asphalt and SBS&TiO2 asphalt were 2.87 times and 3.31 times that of SBS&CR asphalt, respectively. This demonstrates that the activation of the SBS polymer phase requires more energy during the stretching process when the rubber powder is not present. SBS&CR asphalt and SBS&TiO2 asphalt showed better tensile properties and aging resistance in terms of the quantitative results of tensile property indicators, indicated by a larger value of fracture ductility, tensile compliance, and the toughness ratio under the same aging condition. According to the AFM results, SBS modifier had little effect on the phase structure of virgin asphalt, while TiO2 modifier increased the number of bee phases and made their distribution more uniform, indicating the formation of a more stable phase structure system. This may contribute to its better tensile properties and aging resistance. Moreover, TiO2 molecules inhibited the aggregation behavior of polar molecules during the aging process, which led to a reduction in surface roughness. By comparison, the effect of aging on the phase structure of SBS&CR asphalt was more significant among the three modified asphalts. This result can be attributed to the interaction between rubber powder particles and asphalt.

Tribological performance of TiO2 nanoparticle-oil-water emulsion in the hot rolling process

This study aims to evaluate the lubrication performance of a nano-TiO2 oil-in-water (O/W) emulsion during the hot rolling process. A series of O/W emulsions with varying concentrations of TiO2 nanoparticles (0.05, 0.1, 0.3, and 0.5 wt.%) were synthesized. Tribological tests were conducted under a load of 70 N for 10 minutes to determine the optimal concentration based on anti-frictional properties. The O/W nano-emulsion optimized with a 0.1 wt.% concentration of TiO2 applied in the hot rolling process of IS 2062 E250 grade steel. This application resulted in a reduction of rolling force (RF) and surface roughness, suggesting its potential as an alternative lubricant. The results indicated superior antifriction performance at a TiO2 concentration of 0.1 wt.%, leading to a 15% reduction in RF. Additionally, the use of the nano-emulsion contributed to a significant reduction in oxide scale formation. Surface roughness measurements of the rolled samples revealed a 19% decrease, with a roughness value of 2.125 µm, compared to samples rolled with a nano-free O/W emulsion. These findings suggest that nano-TiO2 O/W emulsions could serve as an effective alternative to conventional O/W emulsions in future industrial metalworking applications.

Elucidating the microstructural and optoelectronic properties evolution of sputtered Al-doped MZO thin films

This study involves the deposition of magnesium-doped zinc oxide (MZO) thin films through radio frequency (RF) magnetron sputtering, followed by annealing at temperatures of 350 °C, 450 °C, and 550 °C. Since there is no significant impact of annealing temperatures on MZO thin films, MZO and aluminium-doped zinc oxide (AZO) were co-sputtered to deposit Al-doped MZO (AMZO) thin films. The grown AMZO films were subsequently annealed at 350 °C, 450 °C and 550 °C to regulate their microstructural and optoelectronic characteristics. The X-ray diffraction (XRD) analysis revealed that AMZO films exhibited a predominant (0 0 2) orientation with a single intense diffraction peak, showcasing a wurtzite structure. The field emission scanning electron microscopy (FESEM) presented an increment in grain size for MZO and AMZO films from 31.3 to 64.7 nm and 57.0–64.8 nm, respectively. Furthermore, the atomic force microscopy (AFM) analysis demonstrated a substantial reduction in surface roughness from 1.67 to 1.58 nm for AMZO films annealed at 550 °C compared to MZO films. Notably, the optical band gap changed from 3.64 to 3.32 eV, which was influenced by both the Al content and annealing temperature. The carrier concentration for as deposited and annealed MZO films remained in the orders of 1014 cm−3, whereas AMZO and AMZO films annealed at 550 °C exhibited higher carrier concentrations, in the orders of 1016 cm−3 and 1020 cm−3, respectively. Remarkably, low resistivity (2.10 × 10−2 Ω cm) was observed for AMZO films annealed at 550 °C. Based on these findings, AMZO films exhibited prospect as a buffer layer for CdTe thin films solar cell applications.