The additively manufactured definitive resins have been proposed for implant-supported restorations nowadays due to its shock absorbing capacity; however, there are limited studies evaluating the effects of different implant-supported crown and abutment materials on stress distribution in implant components and peri-implant bone. This finite element analysis (FEA) aimed to evaluate stress distribution in implant components and the peri-implant bone using different combinations of computer-aided design and computer-aided manufacturing (CAD/CAM) zirconia and three-dimensional (3D) printed ceramic filled hybrid materials for crown and CAD/CAM custom abutment. 3D models of a bone-level implant system and titanium base (Ti-base) abutments were created using standard tessellation language (STL) data. A mandibular first molar implant-supported crown was modelled with five different combinations of CAD/CAM zirconia and 3D printed ceramic filled hybrid materials for crown and CAD/CAM custom abutment. A vertical load of 600 N and an oblique load of 225 N at 45° were applied. Stress distribution in implant components and peri-implant bone were evaluated using von Mises stress (VMS) analysis. Under vertical and oblique loading, the overall von Mises stress values across all groups ranged from 102 to 214 MPa in the crown, 45–423 MPa in the CAD/CAM custom abutment, 158–225 MPa in the abutment screw, 242–580 MPa in the Ti-base abutment, 201–461 MPa in the fixture, and 122–204 MPa in the cortical bone. Under both loads, groups CAD/CAM zirconia crown paired with 3D printed ceramic filled hybrid materials abutment notably demonstrated reduced stress at the CAD/CAM custom abutment (471

Fe-based bulk metallic glasses (BMGs) have high potential to be applied in biomedical devices, automotive and aerospace, and sports equipment due to their exceptional mechanical, physical and chemical properties. However, they have low glass forming ability (GFA) and high tendency to crack during solidification, restricting its critical casting size to a few millimeters which represents the bottleneck for broader industrial-scale utilization. Metal Additive Manufacturing (MAM) is a promising strategy to fabricate BMGs with larger sizes and complex geometries, bypassing the current bottleneck. Nevertheless, the fusion-based-AM techniques such as selective laser melting (SLM) trigger crystallization of the amorphous structure due to high thermal input. Sinter-based MAM is another strategy that decouples shaping and consolidation, preventing cracking and ability to process difficult-to-print materials. Lithography MAM (LMAM) offers exceptional surface quality, dimensional accuracy, and ability to process fine powders. Hence, this research proposes a novel approach hybridizing LMAM and pressure-less sintering approach to fabricate high-precision, complex, and dense monolithic Fe-based bulk metallic glass (BMG) components, achieving maximum amorphous content and exceeding the critical casting thickness limitations. The sample achieved a relative density of 65.934

Recent years have seen rapid adoption of laser powder bed fusion (L-PBF) for fabricating biomedical implants from commercially pure titanium (CP-Ti). In this study, fluorapatite (FA, Ca10(PO4)6F2) nanopowder was mixed with CP-Ti at 1 wt.

The effects of friction stir processing (FSP) parameters—specifically, rotational speeds (RS: 1000 rpm, 1250 rpm, 1500 rpm) and traverse speeds (TS: 15 mm/min, 30 mm/min, 45 mm/min)—on the microstructure and temperature distribution of WE43 magnesium alloy have been systematically investigated. The optimal combination of RS 1250 rpm and TS 30 mm/min produced the finest microstructure with an average grain size of 4.32 μm, indicating effective dynamic recrystallization. A predictive mathematical model based on response surface methodology (RSM) was established to quantify the influence of RS and TS on grain size, RS was the dominant factor and the model showed strong fidelity (R2 ≈ 0.98, Adeq precision ≈ 17). Furthermore, temperature distribution during FSP was analyzed using both theoretical calculations and finite element simulations in Abaqus. The results revealed notable temperature gradients between different zones, particularly between the advancing and retreating sides, with RS having a stronger influence on heat generation. These findings contribute to a deeper understanding of microstructural evolution and thermal behavior in WE43 alloy during FSP, offering practical guidance for process optimization. The insights are also relevant to future applications in biomedical implants, where grain refinement and thermal control are essential for improving corrosion resistance and mechanical performance.

Biodiesel is an eco-friendly source of energy that is synthesized from plant or animal-based oils and fats. However, the commercial use of biodiesel is limited due to its drawbacks such as auto-oxidation and moisture absorption, leading to accelerated corrosion of the metallic parts and degradation of wear resistance. In this work, a novel amorphous metal coating was proposed to promote the wear and corrosion resistance under multigrade diesel engine oil (15W-40) diluted with 7% palm oil-based biodiesel (B30). The coating was performed using laser cladding technique at different scanning speeds (40 and 60 mm/s) and constant laser power 280 W. Microstructure investigation and X-ray diffraction confirmed amorphous structure and crystalline phase (FeCr). It was found that the wear rate was reduced for the coated specimens by about 90% compared to the uncoated samples. The corrosion rates decreased by 54.74% and 69.96% for scanning speeds 40 and 60 mm/s, respectively. Thanks to the reduced microstructural defects such as grain boundaries in the amorphous structure of the coating. These findings showed that amorphous metal coating provides promising solutions to increase the reliability of using biodiesel without the need for corrosion inhibitors which reduce the combustion efficiency.

This study examines the mechanical and tribological properties of FeCrMoCB amorphous coatings on AISI 52100 bearing steel using laser cladding (LC). Two samples with varying LC parameters were compared to uncoated polished steel. Analytical methods included scanning electron microscopy (SEM), X-ray diffraction (XRD), microhardness testing and tribological tests via a high-frequency reciprocating rig (HFRR) tribometer under both dry and lubricated conditions, were employed. Sample S1 exhibited a microhardness five times that of uncoated steel and a 95% reduction in wear volume loss under dry conditions. Under grease-lubricated, S1 showed a 20% reduction in the coefficient of friction and a 93% reduction in wear volume loss. Sample S2 also outperformed uncoated steel. These results highlight the significant benefits of FeCrMoCB coatings.

The development of hard coating layers emerges as a promising avenue to promote surface properties such as hardness, wear resistance, and, hence, lifetime. Metal nitrides, especially Cr-based, are among the array of available coating materials that stand out for their exceptional tribological performance and chemical stability, particularly at elevated temperatures. In this research, a promising CrNiAlSiN coating is deposited on cast iron substrates to promote the performance and durability of different components made from cast iron in wide applications such as engines parts, gears, and hydraulic components. To promote the adhesion strength, different substrate surface roughness was prepared using emery papers with four different grit sizes (#60, #240, #400, and #800) and denoted as CI-60, CI-240, CI-400 and CI-800. The hardness, wear resistance, and adhesion strength of CrNiAlSiN hard coating were evaluated. The cross-section examination of the coating layer revealed homogeneous, dense, and defect-free CrNiAlSiN coatings with approximately 11 μm thickness. It was found that the highest surface roughness (CI-60) exhibited the lowest failure load (2971.17 mN) and hardness (2272.38 ± 61.96 HV0.2), while sample CI-240 demonstrated the highest failure load (3814.19 mN) and hardness (3533.30 ± 50.73 HV0.2). Meanwhile, the lowest wear rate (0.69 × 10−9 mm3/N.m) was recorded for sample CI-60, while CI-240 recorded a wear rate of 1.07 × 10−9 mm3/N.m; however, the samples CI-400 and CI-800 recorded significant increase in wear rate 1.47 × 10−9 and 3.6 × 10−9 mm3/N.m, respectively. This implies that substrate surface roughness using emery paper has a significant impact on the adhesion strength, hardness, and wear resistance of the hard Cr-based coating.

PurposeThis paper aims to investigate the reciprocating wear resistance of laser-cladded FeCrMoCB amorphous coatings on AISI 52100 steel under both dry and grease-lubricated conditions. It aims to explore the effects of microstructural refinement and lubrication regimes on the tribological performance of the coatings.Design/methodology/approachThis paper opted for an exploratory study of nine Fe-based amorphous coatings were deposited on AISI 52100 substrates using a fiber laser cladding system, with variable process parameters guided by the Taguchi method optimization. The samples underwent tribological testing using a High-Frequency Reciprocating Rig under dry and NLGI 3 grease-lubricated conditions. Characterization techniques included Scanning Electron Microscopy, X-ray Diffraction, Energy Dispersive X-ray spectroscopy and Vickers microhardness testing.FindingsThis paper provides empirical insights about nine optimized coatings samples, particularly samples S6 and S7, exhibited significantly enhanced wear resistance. Under dry conditions, these coatings reduced the coefficient of friction (COF) by up to 30% and wear volume loss by up to 75% compared to uncoated steel. Grease lubrication further lowered COF by 24.5%-35.6% and improved wear rates by 30%-40%. The results highlight a strong correlation between refined microstructure, high amorphous content and tribological performance.Research limitations/implicationsBecause of the chosen research approach, the findings are limited to controlled laboratory conditions and specific loading scenarios. Therefore, further studies are needed to assess long-term durability under cyclic or thermal loads.Practical implicationsThis paper includes implications for the developed coatings are suitable for industrial components subjected to varying lubrication regimes, such as in bearings or gears, offering enhanced durability and reduced maintenance needs.Social implicationsThe development of high-performance, wear-resistant coatings such as laser-cladded Fe-based amorphous materials contributes to longer-lasting mechanical components, which can reduce industrial waste, lower energy consumption and support more sustainable manufacturing practices. By improving the efficiency of components in transportation and heavy machinery sectors, this research aligns with global efforts toward greener technologies and resource conservation.Originality/valueThis study provides novel comparative insights into the performance of laser-cladded Fe-based amorphous coatings under different lubrication regimes, showcasing their potential for industrial wear protection applications.Peer reviewThe peer review history for this article is available at: Link to the cited website

In optical applications requiring high light transmission, fogging on transparent substrates remains a considerable hurdle. Despite advancements in antifogging coating methods, opportunities for enhancing photocatalytic effects, surface roughness, long-term stability, and substrate adhesion persist. Doping TiO2 with scandia and zirconia emerges as a strategy to enhance these characteristics as well as the reliance on UV exposure. This study presents the fabrication of Sc2O3/ZrO2 co-doped TiO2 composite thin layer on silica glass slides by employing powder-based magnetron sputtering (PMS). The effects of dopants variation in the range of less than 1 % are investigated on the performance of antifogging. After the films' fabrication, samples are undergone steam and fog evaluation tests followed with water contact angle (WCA) measurements. Subsequently, upon an exposure to weathering condition, some selected samples are tested for SEM, UV-VIS, AFM and adhesive test, scrutinizing superhydrophilicity and durability for antifogging performance. A promising outcome emerged with (0.5 % Sc2O3, 0.5 %ZrO2) sample, boasting 98.5 % optical transparency achieving superhydrophilicity with WCA of 6.7 degrees. The sample also performs only 3 % transmittance attenuation and yet, all samples exhibit stable hydrophilicity after weathering test. Practical implications are substantial, positioning Sc2O3-ZrO2 co-doped TiO2 thin film as an attractive option for optical lenses, offering remarkable antifogging, transparency, and durability.

The search for sustainable, cost-effective and environmentally friendly corrosion inhibitors for hydrochloric acid (HCl) solution in industrial applications has garnered increasing interest in plant extracts and their refined metabolites. In this research, Cleome arabica L. (CA) extract, found in the Algerian Sahara, was considered due to its low cost compared to other studied plants and higher content of active compounds, thereby emerging as a promising candidate and offering the potential to promote a circular economy model. This study assessed the effectiveness of CA extract as a green corrosion inhibitor for AISI 1045 carbon steel in 0.5 M HCl solution and highlighted its potential to advance the field of green corrosion inhibitors. ATR-FTIR and LC-ESI-MS/MS analyses revealed the presence of significant organic compounds, including coumaric acid (74.58%), 4-methoxybenzoic acid (12.53%), and kaempferol (8.05%), which contributed to the corrosion inhibition. The inhibitory effectiveness of the CA extract was evaluated at five concentrations, ranging from 0.125 to 1 g L-1, using weight loss measurements, potentiodynamic polarization (PDP) and electrochemical impedance spectroscopy (EIS). The highest inhibition efficiency (eta = 94.45%) was observed at a CA extract concentration of 1 g L-1 after 196 hours of immersion in 0.5 M HCl. Thermodynamic analysis using the Langmuir adsorption isotherm yielded a Delta Gads value of -24.737 kJ mol-1, indicating the spontaneous adsorption of CA molecules onto the AISI 1045 surfaces, forming a protective layer, which was confirmed by SEM/EDX analysis. Density functional theory (DFT) calculations showed a significant correlation with the experimental data, confirming that CA extract is a highly efficient and environmentally friendly corrosion inhibitor.

Biodiesel and bio-lubricants became desirable options as alternative fuel and engine oil, respectively, to meet sustainability goals. However, their effects on the performance and longevity of engines are not wellestablished yet. The lubricity performance of engine oils is affected by oxidation and biodiesel dilution, potentially resulting in reduced efficiency and tribological characteristics. This research investigates the effect of oxidation on the physicochemical and tribological properties of aged pentaerythritol (PE) ester diluted with 0%, 1%, 5% and 10% palm oil biodiesel blend (B30) as well as 5% B30 + 0.2% antioxidant additive and compared to pure PE ester. The results showed that ageing and biodiesel dilution increased the kinematic and dynamic by 504.02-521.87% at 40 degree celsius and 148.25-154.44% at 100 degree celsius. Additionally, they significantly improved the coefficient of friction (from > 0.1 to less than 0.06) and the wear rate compared to unaged-undiluted PE ester. It was found that the antioxidant additive reduced the dynamic and kinematic viscosities which resulted in higher COF and wear rate compared to the aged and biodiesel diluted samples.

Due to their outstanding corrosion resistance, mechanical characteristics and low specific density, AA5083 and AA6061-T6 Al alloys are used in the aerospace, automotive and marine sectors. Joining such dissimilar Al alloys using conventional fusion welding techniques is very challenging. In contrast, laser beam welding (LBW) is a non-conventional welding technique that is promising to weld dissimilar materials. The viability of welding dissimilar AA5083 and AA6061-T6 joints using fibre laser welding are examined herein. The effect of laser power and welding speed on the morphological, microstructural, microhardness and tensile strength of the welded joints was assessed and revealed that increasing welding power resulted in deeper keyhole penetration. Microporosities were formed due to Mg evaporation and shrinkages; however, the existence of these porosities did not show significant effect on the tensile strength. The microhardness values indicate that the welds were harder than the AA6061 and AA5083 base metals. This is explained by the existence of Mg2Si phase in the AA5083-AA6061 dissimilar junction in addition to the grain size circumstances. The fracture examination showed brittle fracture pattern that is regarded to the formation of brittle intermetallic compound (IMC) phases of Mg2Si, in addition to the inter-dendritic brittle phases of other sites as they were frequently inter-granular.

Nowadays, magnesium alloys are emerging in biomedical implants for their similar properties to natural bones. However, the rapid degradation of magnesium alloys in biological media hinders successful implantation. Refinement of microstructure, as well as reinforcement particles can significantly improve the degradation rate. In this work, multi-pass friction stir processing (FSP) was proposed to synthesize WE43/nano-hydroxyapatite (nHA) surface composite, the microstructure, reinforced particle distribution, micro-hardness, corrosion behavior and in-vitro bioactivity were studied. The subsequent FSP passes of WE43 alloy and WE43/nHA composite refined the grain size which was reduced by 94.29 % and 95.92 % (2.63 and 1.88 µm, respectively) compared to base metal after three passes. This resulted in increasing the microhardness by 120 % (90.86 HV0.1) and 135 % (105.59 HV0.1) for the WE43 and WE43-nHA, respectively. It is found that increasing FSP passes improved the uniform distribution of nHA particles within the composite matrix which led to improved corrosion resistance and less degradation rate. The corrosion rate of the FSPed WE43/nHA composite after three passes was reduced by 38.2 % (4.13 mm/year) and the degradation rate was reduced by 69.7 % (2.87 mm/y). This is attributed to secondary phase (Mg24Y5 and Mg41Nd5) particle fragmentation and redistribution, as well as a homogeneous distribution of nHA. Additionally, the growing Ca-P and Mg(OH)2 layer formed on the surface represented a protective layer that reduced the degradation rate. The wettability test revealed a relatively hydrophilic surface with water contact angle of 49.1 ± 2.2° compared to 71.2 ± 2.1° for base metal. Also, biomineralization test showed that apatite layer grew after immersion 7d in simulated body fluid with atomic ratio of Ca/P 1.60 approaching the stoichiometric ratio (1.67) indicating superior bioactivity of FSPed WE43/nHA composite after three passes. These results raise that the grain refinement by FSP and introduction of nHA particles significantly improved the degradation rate and in-vitro bioactivity of WE43 alloy for biomedical applications.

As a fourth-generation biodegradable material for biomedical applications, magnesium alloys are widely used for their light weight, low modulus, and biocompatibility, but their hardness and corrosion resistance need to be improved. AZ-series Mg alloys have been studied intensively. However, they contains Al which is hazardous to human health. WE43 Mg alloy is another promising alloy that is applied in automotive and aerospace for its corrosion resistance and stability at high temperatures (up to 300 °C). But its corrosion resistance in biological fluids is still lacking and needs further improvement. Friction stir processing (FSP) is a promising surface modification technique that able to refine the microstructure significantly and improves the corrosion resistance. In this research, the effect of rotational speed and traverse speed on the macro and microstructure as well as microhardness of Mg alloy WE43, and corrosion resistance in phosphate buffer saline, has been examined and determined. Subsequently, FSP parameters were analyzed and optimized by using response surface methodology with central-composite-design, and the mathematical models were obtained. The predicted results from models were consistent with the experiments. The SEM examinations showed that FSP reduced the average grain size from 6.64 μm for BM to as low as 4.32 μm. Additionally, the highest microhardness value was 87.1 HV (increase by 15.3

Fogging of transparent surface is the condensation of water-vapor in the air into small discrete liquid drops on the surface, causing scatters of incident light and create a blurry vision. In recent technology development, coating using superhydrophobic and superhydrophilic materials characteristics have been an attractive strategy to induce antifogging property to minimize the light scattering. Inorganic materials such as TiO2, SiO2, and ZnO have been widely explored for this purpose. In this review, the fundamentals of antifogging strategies and materials choice are covered as well as the different techniques used to prepare inorganic antifogging coatings. Further, this review covers the various testing methods involved for evaluation of antifogging behavior and other related properties. Additionally, the review includes potential of applying different techniques for the purpose of industrial scale. Towards the end, the optimization and statistical analysis of antifogging coatings using computer-aided techniques are briefly described to highlight effort in this mode of study. Before ending with summary, examples of antifogging potential application are shared to appreciate its benefit.

The near equiatomic Ti-51at %Ni alloy has excellent corrosion resistance, strength, shape memory and pseudoelastic behaviour. However, it is lacking biocompatibility due to the release of hazardous Ni-ions when used as an implant. Thus, this research proposes optimizing the fabrication of multilayer Ti/TiN coating on Ti-51at %Ni alloy using magnetron sputtering. The hardness and adhesion strength are crucial properties to sustain external bearing loads and to ensure the durability of the coating. The process parameters of magnetron sputtering were optimized using Taguchi method. The analysis showed that optimum adhesion strength was obtained at 370 W, 100 degrees C, 50 V and 5 sccm with respect to DC power, substrate temperature, bias voltage and nitrogen flow, respectively. Whereas, the optimum hardness was obtained at 370 W, 150 degrees C, 75 V and 5 sccm. The confirmation test evidenced the hardness and adhesion strength improvement by 6.83 % and 10.74 %, respectively. The results of the optimized substrate surface showed a dense and compact growth of the deposited layer with the absence of cracks and pores. Finally, this research demonstrated a promising durable multilayer Ti/TiN coating on Ti-51at %Ni for biomedical applications.

This work explored the interfacial microstructure, element diffusion, mechanical properties and metallurgical bonding mechanism of 316L-AlSi10Mg multi-material parts fabricated by laser powder bed fusion (LPBF). Experimental results revealed that insufficient volumetric energy density (VED) of the laser caused lack-fusion porosity in the 316L-AlSi10Mg transition zone, while too high VED produced keyhole-induced porosity defects. Using the optimal process parameters, multi-material parts can be produced with a good interface metallurgical bonding without significant defects. The partial Fe-FCC phase in 316L stainless steel changed into the Fe-BCC structure, and this shift has also changed the preferred orientation of the grains. The intermetallic compound Al5Fe2 and AlFe phases were found in the transition zone. In addition, Al-Fe icosahedral quasicrystals with five-fold symmetry were found at the boundary of the molten pool, which was caused by an extremely high cooling rate. The tensile strength of 316L-AlSi10Mg specimens is higher than that of AlSi10Mg but lower than that of 316L. In contrast to the 316L and AlSi10Mg regions, the fracture mechanism of multi-material fusion zone exhibits a quasi-cleavage fracture mode. The Vickers microhardness of the Al-Fe interface zone was higher than that of 316L with an average value of 235.57 HV0.2 and AlSi10Mg with 124.59 HV0.2, and the interfacial maximum hardness reached 526.68 HV0.2, which was caused by the very hard intermetallic compound Al5Fe2 and AlFe. The metallurgical bonding mechanism of multi-materials was that the dissimilar metals were mixed and in-situ alloyed in the molten pool by the Marangoni convection-induced strong circular flow during LPBF processing. (c) 2023 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

Metallic glasses are a new class of metallic alloys that attract increasing attention in bone implants due to their ultrahigh wear resistance and hardness, high toughness and superior strength. However, their cytotoxicity and biocorrosion resistance are still under investigation. In this research, the cytotoxicity and biocorrosion resistance of iron-based metallic glass composite coating are explored. To approach real-life conditions, the biocorrosion resistance of the proposed coating in phosphate buffer saline (PBS) is evaluated via immersion test for 30 days followed by an electrochemical corrosion test. Then, human bone cells (MG-63) are cultured on corroded samples and the cell viability is determined using MTT assay, in addition to cell attachment examination. The results revealed the formation of a metallic glass composite layer with 78.76

The alumina nanotubular arrays (Al2O3 NTs) are a promising candidate for application in bone and dental implants for their better mechanical and chemical behavior in the human body compared to titanium. Nevertheless, the biocompatibility and antibacterial activity of Al2O3 NTs still need further improvement to meet the requirements of safe implants. In this research, Al2O3 NTs coating was proposed on Ti-6Al-4 V via magnetron sputtering pure aluminum followed by an anodization and sealing process, then heat treated for 1 h at 450 degrees C. After that, Ag2O nanoparticles (NPs) were decorated on the nanotubular walls under controlled conditions using magnetron sputtering. The findings demonstrated that the proposed Al2O3 NTs-Ag2O NPs promoted in-vitro bioactivity alongside excellent antibacterial activity against E.coli and S.aureus bacteria within 4 h and 6 h, respectively. Additionally, the cell-culture showed healthy growth of the human osteoblast cells (HOb) on the Al2O3 NTs-Ag2O NPs. The new design of coating also shows that the total cumulative Ag+released after 14 days is significantly low which is safe and provides the long-term antibacterial activity. It is illustrated that Al2O3 NTsAg2O NPs have promising biomedical properties to enhance the biofunctionality of biomedical-grade Ti-6Al-4 V implants.