Material Surface Research Articles

Rapid carbonate precipitation induced by carbamate coating: A new approach to form impermeable thin barrier and its mechanism

Various coating strategies have been explored in the past to prevent the ingress of aggressive substances into concrete. However, either the durability or performance is still far from satisfaction. Here, carbamate solutions were prepared by pre-absorbing CO2 into amino acid salts (AASs) to carbonize the surface of cementitious materials. The high concentration of carbonate ions provided by the carbamate induced rapid surface carbonation, resulting in the formation of an AAS-CaCO3 composite barrier with a thickness of 2–3 μm and possessing high micromechanical properties. Additionally, it was observed that the barrier's effectiveness depends on the molecular structures of the amino acids employed. Coatings formed by arginine-based carbamates demonstrated excellent performances, likely due to the highly compacted calcite particles they produced. This easy-to-operate and effective strategy has the potential to open new avenues for the development of highly durable and impermeable coating barriers for practical applications.

Modelling and Fabrication of Tri-Head Gantry Crane Model

During the manufacturing process, various raw materials and finished goods have to be handled in manufacturing industries. As the shapes and material properties of each raw material / finished good to be handled are different, it gets difficult for a single-head crane to handle diverse materials. At present forklifts and hook-headed cranes are being used for this purpose, but it requires a lot of labor and time to handle the materials and finished goods due to miscellaneous work associated with this equipment. Looking at the present day’s industrial requirements, it becomes inevitable for every manufacturing company to use the least manpower to offer competitive prices to customers without compromising the timely completion of projects. Tri head gantry crane is one of the best solutions to handle various raw materials and finished goods with the least manpower & time. The tri-headed gantry crane head consists of electromagnets to hold flat surfaces of magnetic materials, where the grab helps in holding the cylindrical, square, and rectangular materials finally if the material or a finished good is not in the shape that can be handled by using grab or magnetic heads, then we can use hook arrangement. The project involves study of various types of handling equipment being used in manufacturing industries, modeling and fabrication of tri-headed gantry crane model and testing of mechanisms of the model for handling diverse shaped materials [3].

A comprehensive study of AFM stiffness measurements on inclined surfaces: theoretical, numerical, and experimental evaluation using a Hertz approach

Atomic Force Microscopy (AFM) is a leading nanoscale technique known for its significant advantages in the analysis of soft materials and biological samples. Traditional AFM data analysis is often based on the Hertz model, which assumes perpendicular indentation of a planar sample. However, this assumption is not always valid due to the varying geometries of soft materials, whether natural, synthetic or biological. In this study, we present a new theoretical model that incorporates correction coefficients into Hertz’s model to account for cone-like and spherical probes, and to consider local tilt at the probe-sample interface. We validate our model using finite element analysis (FEA) simulations and experimental AFM measurements on tilted polyacrylamide gels. Our results highlight the need to include local tilt at the probe-sample contact to ensure accurate AFM measurements. This represents a step forward in our understanding of the elastic properties at the surface of soft materials in the broadest sense.

Experimental investigation on optimizing wire-cut EDM process parameters of hybrid MMC(AA7475/ZrO2/Gr) using artificial neural network

Abstract Wire cut Electrical discharge machining (WCEDM) is a widely used method for machining complex shapes in advanced materials like metal matrix composites (MMCs) and hybrid metal matrix composites (HMMCs). To address these challenges, this study focusses on the wire-cut EDM (WCEDM) process of a workpiece made from zirconium dioxide and graphite-reinforced aluminium alloy 7475 with a molybdenum electrode. The effects of input process variables such as peak current (IP), pulse-on-time (TON), and flushing pressure (PF) on the output response features are investigated. These output responses include material removal rate (MRR), surface roughness (SR), and wire wear ratio (WWR). To optimise the process parameters, the Taguchi design technique is used. An artificial neural network (ANN) with a feed-forward back propagation architecture is utilised to find the best fit for the optimisation challenges. ANN predicted the results with an accuracy of 97.81% for MRR, 97.95 % for SR and 95.865% for WWR. The results reveal that the WCEDM of AA7475/ZrO2/Gr with a molybdenum electrode achieved minimal WWR and SR, while maximizing the MRR.

Synthesis and antimicrobial activity of yttrium-doped cerium oxide nano-composite against wound pathogen

Abstract Nanocomposite materials have attracted considerable interest in several disciplines owing to their distinctive characteristics and possible uses. The primary objective of this study was to synthesize and characterize a nanocomposite material consisting of cerium that has been doped with yttrium. The shape, structure, and properties of the synthesized nanocomposite was characterized using various characterization techniques including ultraviolet spectrophotometry, Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), X-ray diffraction (XRD), zeta potential measurements, dynamic light scattering (DLS), and Fourier-transform infrared spectroscopy (FTIR).The antibacterial activity of the nanocomposite was assessed against a range of pathogenic bacteria including Gram-positive bacteria - Enterococcus faecalis, Staphylococcus aureus, and Gram-negative bacteria- Escherichia coli, Pseudomonas aeruginosa using standard microbiological techniques. The results indicate that the nanocomposite possesses strong antibacterial properties against a wide range of microorganisms, showcasing its potential as a highly effective antimicrobial agent for diverse applications in the biological, environmental, and industrial fields. Hemolysis is the process of red blood cell destruction, resulting in the release of hemoglobin into the surrounding fluid. In this study, 0.7:0.3M nanocomposite had showed effective biocompatibility with less than 5%. Furthermore, this particular composite remained identical in different time intervals, while other composites would normally fluctuate. Research has shown that meticulous material design and surface modification can reduce the harmful effects on red blood cells, hence improving the safety of nanocomposite for therapeutic purposes. In summary, this study offers valuable information on the creation, analysis, and assessment of nanocomposite materials with antimicrobial properties.

Taguchi optimization of Wire EDM process parameters for machining LM5 aluminium alloy.

LM5 alloy is suitable for metal castings for marine and aesthetic uses due to its admirable resistance to corrosion. In order to make intricate shapes in the LM5 alloy, this study intends to assess the impact of Wire Electric Discharge Machining process variables, like Pulse on Time (Ton), Pulse off Time (Toff), Gap Voltage (GV) and Wire Feed (WF) on responses like Material Removal Rate (MRR), Surface Roughness (SR), and Kerf Width (Kw). The LM5 aluminium alloy plate was produced through stir casting process. SEM, EDAX and XRD images confirm the LM5 Al alloy's microstructure and crystal structure. WEDM studies were conducted using design of experiments approach based on L9 orthogonal array and analysed using Taguchi's Signal to Noise Ratio (S/N) analysis. Pulse on Time has the greatest statistical effects on MRR (68.25%), SR (79.46%) and kerf (81.97%). In order to assess the surface integrity of the WEDM machined surfaces, the SEM study on the topography was conducted using the optimum surface roughness process variables: Ton 110 μs, Toff 50 μs, GV 40 V, and WF 9 m/min. SEM images show the recast layer and its thickness. The average absolute error for MRR is 1.69%, SR is 3.89% and kerf is 0.88%, based on mathematical (linear regression) models. The Taguchi's Signal to Noise ratio analysis is the most appropriate for single objective optimization of responses.

Evaluation of Hardness and Elastic Modulus of Polymer Materials Through Micro-Scratch Method: An Empirical Study

ABSTRACT A number of researchers have focused on scratch methodologies to examine the surface properties of materials. Scratch testing is primarily employed to examine tribological behavior and coating failure. This study attempts to determine the hardness (H) and elastic modulus (E) of polymeric materials via the scratch method. The research performed a progressive loading scratch test on Poly-(ether-ether ketone) (PEEK), Poly(methyl methacrylate) (PMMA), Poly-tetra-fluoro-ethylene (PTFE), polyvinyl chloride (PVC), and High-density polyethylene (HDPE). The least-squares curve fitting model was used to develop two models for assessing the H and E of materials based on indentation and scratch parameters. The H is determined by tangential force, scratch width, residual depth, and E calculated from the recovered depth and additional scratch parameters. Validation of both models indicates a maximum error of around 5%, indicating that the recently established models align well with experimental data. This study presents two robust models for assessing material surface attributes derived from a single scratch test with additional parameters.

Effect of Mechanical Damage on Tritium Permeability Resistance of FeAl/Al2O3 Coating on 316L Stainless Steel

Depositing a tritium permeation barrier on the surface of materials is a key method for reducing tritium permeability. During actual operational processes, the surface of the tritium permeation barrier may experience mechanical damage, such as spalling and scratches. The hydrogen permeability resistance of the coating will degrade due to such forms of mechanical damage. It is a significant engineering challenge to evaluate the impact of these damages on the coating’s tritium resistance. In this experiment, the mechanical damage to the FeAl/Al2O3 tritium permeation barrier on 316L stainless steel was simulated through scratching, debonding, and thermal shock. Subsequently, a hydrogen isotope gas drive permeation (GDP) test was conducted. The influence of the degree of mechanical damage on the coating’s tritium permeation behavior was assessed and discussed. The results indicate that, under the same damage mechanism, the coating’s tritium permeability resistance is positively correlated with the integrity of the coating. Additionally, the impact of scratches on the coating surface is more severe than that of other damage mechanisms.

Boundary Layers of Circumplanetary Disks around Spinning Planets. II. Global Modes with Azimuthal Magnetic Fields

The accretion of material from disks onto weakly magnetized objects invariably involves its traversal through a material surface, known as the boundary layer (BL). Our prior studies have revealed two distinct global wave modes for circumplanetary disks with BLs exhibiting opposite behaviors in spin modulation. We perform a detailed analysis of the effects of magnetic fields on these global modes, highlighting how magnetic resonances and turning points could complicate the wave dynamics. The angular momentum flux becomes positive near the BL with increasing magnetic field strength. We also examine the perturbation profile to demonstrate the amplification of magnetic fields within the BL. The dependence of growth rates on the magnetic field strength and the spin rate are systematically investigated. We find that stronger magnetic fields tend to result in lower terminal spin rates. We stress the potential possibility of the formation of angular momentum belts and pressure bumps. The implications for the spin evolution and quasiperiodic oscillations observed in compact objects are also briefly discussed. Our calculations advance the understanding of magnetohydrodynamical accretion processes and lay a foundation for observational studies and numerical simulations.

Preparation of high strength and rigidity carbon layer on SiO material surface by dynamic CVD method using gas carbon source C2H2

The main issue in the application of silicon-based negative electrode materials is the inevitable volume expansion, leading to negative electrode material fracture, which severely impacts the performance of batteries. This study employed Chemical Vapor Deposition (CVD) (C2H2@SiO), solid-phase coating method (Pitch@SiO), and liquid-phase coating method (RGFQ@SiO) to coat the surface of SiO materials with a dense amorphous carbon structure. Material property analysis revealed that C2H2@SiO has a relatively small specific surface area (1.8 m2 g−1) and surface carbon increment (2.4 %). It exhibited high reversible specific capacity (1563.4 mAh g−1), high initial Coulombic efficiency (81.45 %), and low volume expansion rate (9.3 %). Mechanical performance testing indicated that the surface carbon layer Young's modulus of C2H2@SiO was the highest (35 GPa), suggesting that using the CVD method to obtain a dense carbon layer can enhance the structural strength of the material. Based on the electrochemical-mechanical coupling theory simulation analysis of the stress during the charge-discharge process of electrode materials, the evolution of concentration and stress field during lithium insertion process was obtained, showing that the coating can further improve the electrochemical and mechanical performance of the negative electrode materials effectively. Additionally, the negative electrode sheets fabricated using sample C2H2@SiO were assembled into 18650 cylindrical batteries, exhibiting excellent cycling performance in 1000 cycles at 25 °C with a capacity retention rate of 85.7 %, along with good rate capability and high/low-temperature performance. The conclusions of this study provide certain guidance for the design and optimization of negative electrode materials for battery electrodes.

Failure mechanisms and influencing factors on orthopaedic knee implant failure – A comprehensive review

Background Total knee replacement (TKR) is an effective orthopaedic surgical procedure to confront osteoarthritis and restore bone joint mobility, relieve pain, and enhance the quality of life. The improvements in implant design and the use of high-wear resistance polyethylene bearings improve the survival of implants. Despite the advancements, the implants still failed and required revision surgery. Also, with an increase in the trend of young patients getting knee replacements, there is a possibility of a higher revision rate. Thus, understanding the failure cause, failure mechanisms and the influencing factors is pertinent. Methods A systematic review of the available literature was performed for different modes of failure. All the observations are collated and found the more predominant failure modes. Also, the data pertaining to the failure mechanisms, and the influencing factors of the failure mechanisms are collected from various literature and provided comprehensively. Results Infection (30%) becomes the primary cause of implant failure followed by loosening (20%) and instability (18%). The types of wear on knee implants are polyethylene wear, backside wear, impingement wear, and corrosive wear. The factors influencing these wear are material processing, shelf age, implant design, surface topography, and activity level. Conclusions Moderately cross-linked, and sequentially processed polyethylene has better wear resistance. Less conformal contact with minimum shelf age provides less wear at articulation and backside. A polished tibial tray with a sophisticated locking mechanism reduces the backside wear of PE, and proper design consideration could reduce impingement wear.

Investigation into micro slotting of Cu-based shape memory alloy via µ-ECM using ethylene glycol mixed aqueous NaCl electrolyte

ABSTRACT Micro-Electrochemical Machining (µECM) presents significant promise as a future micromachining process offering higher machining rates, improved precision and the ability to work with a wide range of materials. Cu-based shape memory alloys (SMAs) have exceptional properties that make them quite difficult to machine using traditional techniques. In this investigation a new electrolyte solution consisting of ethylene glycol (EG) and NaCl has been explored while attempting µECM of Cu-SMA. The Cu-based shape memory alloy used consists primarily of Cu-53.19%, Zn-41.50%, and 5.2% other elements. Four different parameter combinations selected based on pilot experiments were used for the main experimentation conducted in four sub-sets. The influence of micromachining parameters including machining voltage, electrolyte concentration and micro-tool feed rate on µECM characteristics such as material removal rate (MRR) and surface roughness (SR) during micro-slot formation has been investigated. With the identified optimum parameters, a high-quality micro-slot was successfully machined on Cu-based shape memory alloys achieving a material removal rate of 0.323 mg/min and surface roughness of 0.384 μm. The investigation demonstrated that an ethylene glycol electrolyte containing NaCl is more suitable for µECM of micro-slots offering superior surface integrity and shape accuracy compared to a water-based electrolyte.

Far-UVC light (222 nm) efficiently inactivates clinically significant antibiotic-resistant bacteria on diverse material surfaces.

This study is crucial, providing compelling evidence on Far-ultraviolet radiation C (Far-UVC) light's efficacy against clinically significant antibiotic-resistant bacteria-a pressing issue in microbiology and infection control. Our research employs antibiotic-resistant strains from clinically isolated bacteria, emphasizing real-world relevance. Simultaneously, we assess Far-UVC light (222 nm) across diverse material surfaces commonly found in clinical settings. This dual approach ensures practical applicability and broad relevance. Our comprehensive setup and rigorous methodologies unequivocally demonstrate Far-UVC light's potency in combating antibiotic-resistant bacteria. Since 222 nm far-UVC has a disinfection capability and is harmless to mammalian cells, this dual effectiveness positions Far-UVC as a secure tool for infection control, with potential applications in healthcare settings, mitigating antibiotic-resistant bacteria spread, and reducing healthcare-associated infections.

Experimental investigations of chemo-mechanical magneto-rheological finishing of Al-6061 via composite magnetic abrasive

ABSTRACT To achieve flawless soft material surfaces, defects and irregularities must be eliminated. Traditional abrasive-mixing techniques frequently produce surface flaws as a result of abrasive embrittlement, resulting in poor surface-quality. As a result, ensuring an immaculate finish is critical for these surfaces. In contrast, the chemo-mechanical magneto-rheological finishing (CMMRF) process, which employs a composite magnetic abrasive (CMA)-based smart fluid, has proven to be extremely effective at producing nano-finished surfaces. This study used a central-composite-rotatable design (CCRD) based on response surface methodology (RSM) to analyze how CMAs variables, slurry-based parameters, and polishing time affect final surface roughness (R a ) and percentage change in roughness (%∆R a ) for Al-6061. The CMMRF process resulted in a superior Al-surface finish (R a ) of 29 nm and a %∆R a of 91.23%. Statistical models predicted R a and %∆R a values, which matched experimental results. Characterization tests on the final Al-surface revealed significant reduction in initial machining scratches and valleys, resulting in a superior mirror-polished surface via CMA-based polishing.

Effect of Al content on mechanical properties and corrosion performance of novel Fe-Cr-Al alloy steels in a CO2-O2 coexistence environment

The present study involved preparing five novel Fe-Cr-Al alloy steels with varying Al content based on commercially available 3Cr steel. The effect of Al content on the mechanical properties and corrosion performance in a CO2-O2 coexistence environment was investigated in novel Fe-3Cr-(0–2.5)Al alloy steels, and the microhardness, impact, and tensile properties were measured and compared. The corrosion rate, corrosion product film, and corrosion mechanism were studied using a weight-loss method, microscopic characterization, and electrochemical tests. The results showed that the tensile and impact properties of Fe-Cr-Al alloy steels exhibited a decreasing trend with increasing Al content. No localized corrosion was observed at an Al content of 2 wt%, attributed to the formation of a dense amorphous corrosion product film on the material surface and pre-passivation. Among the alloy steels examined in this study, the 3Cr2Al alloy steel exhibited the most optimal balance between mechanical properties and corrosion resistance.

Exploring the potential of Desert Rose fibers (Adenium obesum) for the remediation of oil-contaminated sites

This work proposes the use of Fibers from the pod of Desert Rose, Adenium obesum (DRF), as an alternative for oil removal in spill scenarios and cleaning of contaminated bird feathers. The sorption capacity of biomass was evaluated through kinetics tests, which were adjusted using the Fractal Linear Driving Force (FL-LDF) model. Additionally, capture stability tests were performed to determine the oil retention capacity of the material. Furthermore, the DRF were tested in the cleaning of bird feathers, and the fibers were characterized using Optical Microscopy (OM), SEM, FTIR and TGA. The DRF demonstrated sorption efficiency, with approximately 13.01 ± 1.87 g/g, 14.59 ± 0.58 g/g and 49.12 ± 2.43 g/g, for diesel oils, 20 W50 mineral oil and petroleum, respectively. It was found that these results were achieved by combining the viscosity with the functional groups identified on the material surface, which strongly contributed to the sorption capacity. The sorption kinetics indicated a fast rate in the first minute of testing for diesel oils and 20 W50. The material was still stable, managing to retain 65 %, 83 % and 78 % and removing from the feathers a total of 82 %, 71 % and 81 % of diesel oils, 20 W50 and petroleum. The biomass presented a hollow cylindrical structure, with the presence of grooves and roughness in some regions of its surface with a thin wall, demonstrating to be an efficient and competitive oil sorbent.

STRUCTURAL, MORPHOLOGICAL AND MAGNETIC PROPERTIES OF FUNCTIONALIZED MANGANESE IRON OXIDE NANOPARTICLES FOR BIOLOGICAL APPLICATIONS

The chitosan functionalized MnFe2O4 nanoparticles were synthesized using thermal decomposition method. The morphological, structural and magnetic properties of obtained chitosan functionalized magnetic nanoparticles were studied to assess the feasibility for biomedical applications. The crystallite size of nanoparticles observed using XRD was 15nm. Functional group attachment to surface of nanoparticles was analyzed using FTIR. Particle size of nanoparticles was studied by TEM analysis and it showed that particles were roughly spherical. Thermal stability and bonding strength of ligands to the surface of material was determined using TGA. The magnetization of chitosan functionalized nanoparticles observed by VSM is 56emu/g and VSM showed no coercivity and remanence existence, stipulating the super-paramagnetic behavior. The cell viability of chitosan functionalized nanoparticles was above 85% at concentration up to the 1.0mg mL-1 on mouse fibroblast cell line i.e. L929 cell line. These studies revealed that, MnFe2O4 nanoparticles are potential materials for biomedical applications.

Biological Characterization of Ti6Al4V Additively Manufactured Surfaces: Comparison Between Ultrashort Laser Texturing and Conventional Post-Processing.

Among Additive Manufacturing (AM) technologies, Laser Powder Bed Fusion (LPBF) has made a great contribution to optimizing the production of customized implant materials. However, the design of the ideal surface topography, capable of exerting the best biological effect without drawbacks, is still a subject of study. The aim of the present study is to topographically and biologically characterize AM-produced Ti6Al4V ELI (Extra Low Interstitial)samples by comparing different surface finishing. Vertically and horizontally samples are realized by LPBF with four surface finishing conditions (as-built, corundum-sandblasted, zirconia-sandblasted, femtosecond laser textured). Bioactivity in vitro tests are performed with human osteoblasts evaluating morphology, metabolic activity, and differentiation capabilities in direct contact with surfaces. Scanning electron microscope and profilometry analysis are used to evaluate surface morphology and samples' roughness with and without cells. All tested surfaces show good biocompatibility. The influence of material surface features is evident in the early evaluation, with the most promising results of morphological study for laser texturing. Deposition orientations seem to influence metabolic activities, with XZ orientation more effective than XY. Current data provide the first positive feedback on the biocompatibility of laser texturing finishing, still poorly described in the literature, and support the future clinical development of devices produced with a combination of LPBF and different finishing treatments.

Analysis of the Creep Mechanism of Low-Alloy Steel in Terms of Plastic Deformation

AbstractAs the proportion of renewable energy sources within the energy grid increases, boiler operations increasingly rely on managing disparities in energy supply. This condition substantially curtails their operational lifespan due to frequent switching cycles. Materials exposed to prolonged stress at high temperatures in harsh environments gradually degrade and eventually fail catastrophically. Thus, understanding processes like creep is essential for accurately evaluating the condition of operational components under new operational standards in power plants. In this regard, this paper introduces an innovative methodological framework for analyzing the creep mechanism, focusing on the plastic deformation of a crucial pipeline segment, specifically an elbow composed of 14MoV6-3 steel, both before and after extensive usage periods (164,000 and 302,000 h). The study explored the development of microstrain from the material's surface employing the electron backscattered diffraction method. This analysis assessed how operational durations influence dislocation structural changes, as examined by synchrotron radiation techniques, across a material depth from 0 to 1.5 mm. Based on these observations, the extent of deformation over time was demonstrated. Furthermore, the evolution of precipitation processes was investigated through transmission electron microscopy. These tests allowed to obtain and compare information on the dislocation structure of the tested steel after service in creep conditions, of small and large volumes of material.

Evaluation of optical and mechanical properties of crown materials produced by 3D printing.

The various advantages of crown materials produced using three-dimensional (3D) printers have increased their use in restorative and prosthetic dentistry in recent years. Accordingly, their optical and mechanical properties have become more important. To evaluate the mechanical, surface and optical properties of crown materials produced with 3D printing and computer-aided design (CAD)/computer-aided manufacturing (CAM), which has recently been used frequently in the clinic. The 3-point bending test was used to evaluate the mechanical properties of 2 different crown materials produced with 3D printing (Permanent Crown and VarseoSmile Crown Plus) and a crown material produced using CAD/CAM (Vita Enamic). After the initial color and surface roughness measurements were made, the specimens were immersed in 4 different solutions. The most translucent material was VarseoSmile Crown Plus (p < 0.05). In all specimens, coffee caused the most discoloration (p < 0.05). The effects of the solutions on the roughness were mostly observed in Permanent Crown specimens (p < 0.05). Vita Enamic showed the highest statistically significant values in terms of flexural strength (p < 0.05). The stereolithographic technique among the materials produced by 3D printing can be recommended for use in restorations due to its higher flexural strength.