High Oxidation Resistance Research Articles

Practical High‐Voltage Lithium Metal Batteries Enabled by the In‐Situ Fabrication of Main‐Chain Fluorinated Polymer Electrolytes

Polymer electrolytes are crucial for advancing safe, high‐energy‐density lithium batteries. Therefore, such electrolytes must possess stability with high‐voltage cathodes and lithium metal, ensuring efficient interfacial contact and high room‐temperature ionic conductivity. In this study, we present a novel main‐chain fluorinated polymer electrolyte, FEOP, synthesized through cationic ring‐opening polymerization. FEOP integrates high oxidative resistance of polytetrafluoroethylene with lithium metal compatibility of polyether, achieving an oxidation potential of up to 5.6 V and an anion‐involved solvation structure. The exceptional stability enables NCM811 cells to deliver an impressive cycling life of 2000 cycles at 1 C up to 4.5 V. Furthermore, at ultra‐high cut‐off voltages of 4.7 and 4.9 V, both NCM811 and LNMO cells demonstrate stable cycling over 700 cycles, marking the longest lifespan for polymer‐based batteries under these challenging conditions. Moreover, 4.7 V solid‐state lithium metal pouch cells incorporating FEOP exhibit an energy density of 405.3 Wh kg−1 and maintain stable cycling over 70 cycles, while successfully passing industry‐standard nail penetration tests. Moreover, FEOP demonstrate excellent compatibility with ultra‐high‐loading electrode (70 mg cm−2), achieving an exceptional areal capacity of 16.2 mAh cm−2. These results provide a solid foundation for designing practical electrolytes that enable next‐generation high‐energy‐density and high‐safety solid‐state batteries.

Practical High‐Voltage Lithium Metal Batteries Enabled by the In‐Situ Fabrication of Main‐Chain Fluorinated Polymer Electrolytes

Polymer electrolytes are crucial for advancing safe, high‐energy‐density lithium batteries. Therefore, such electrolytes must possess stability with high‐voltage cathodes and lithium metal, ensuring efficient interfacial contact and high room‐temperature ionic conductivity. In this study, we present a novel main‐chain fluorinated polymer electrolyte, FEOP, synthesized through cationic ring‐opening polymerization. FEOP integrates high oxidative resistance of polytetrafluoroethylene with lithium metal compatibility of polyether, achieving an oxidation potential of up to 5.6 V and an anion‐involved solvation structure. The exceptional stability enables NCM811 cells to deliver an impressive cycling life of 2000 cycles at 1 C up to 4.5 V. Furthermore, at ultra‐high cut‐off voltages of 4.7 and 4.9 V, both NCM811 and LNMO cells demonstrate stable cycling over 700 cycles, marking the longest lifespan for polymer‐based batteries under these challenging conditions. Moreover, 4.7 V solid‐state lithium metal pouch cells incorporating FEOP exhibit an energy density of 405.3 Wh kg−1 and maintain stable cycling over 70 cycles, while successfully passing industry‐standard nail penetration tests. Moreover, FEOP demonstrate excellent compatibility with ultra‐high‐loading electrode (70 mg cm−2), achieving an exceptional areal capacity of 16.2 mAh cm−2. These results provide a solid foundation for designing practical electrolytes that enable next‐generation high‐energy‐density and high‐safety solid‐state batteries.

Oxidation Behavior of Vanadium in Annealed AlCrVY(O)N Thin Films Characterized by X‐ray Absorption Spectroscopy

Great efforts are being made to optimize tool coatings for use at elevated process temperatures. The reason for this is to enable machining with minimized lubrication quantities. During operation, temperatures between 300 and 1000 °C can occur depending on the material and tool design. Thus to enable the machining of high‐strength materials, the tool coatings must be optimized with regard to their temperature resistance, which is also significantly affected by their oxidation properties. AlCrVY(O)N thin films are potential candidates for such coating applications as the addition of V to AlCrN favors the formation of so‐called Magnéli phases at high temperatures, that is, V oxides with varying stoichiometry, to reduce friction. X‐ray absorption spectroscopy is applied to characterize the oxidation behavior of V in the thin films prepared in a combined dcMS/HiPIMS process for as‐deposited AlCrVY(O)N thin films and after thermal treatment in the ambient atmosphere. The V average oxidation state is determined by analyzing the pre‐edge feature at the V K‐edge. Systematic changes in preoxidation, a high oxidation resistance below 800 °C, and promoted V oxidation for higher preoxidized coatings above 800 °C are found.

Laser Cladding Performance and Process Parameter Optimization for Fe90 Alloy

Fe90 alloy has a high weld hardness, good toughness, and high oxidation resistance, and is often used as a cladding material to repair the surfaces of 42CrMo steel structures of large shearer picks. The influence of the laser cladding processing parameters on the microstructure, properties, and formation mechanism of Fe90 alloy layers on the surface of 42CrMo steel was studied. Simulations were conducted to investigate how these processing parameters affect the temperature field and internal stress of the cladding layer. A complex nonlinear relationship between variables and residual stresses in the laser cladding layers obtained by additive manufacturing was fitted. An optimization model for residual stress in the cladding layer was established and an improved genetic algorithm was used for optimization, which resulted in a 15.88% reduction in residual stress. The results show that optimizing the processing parameters increased the amount of Ni-Cr-Fe solid solution in the cladding layer, enhancing its strength and corrosion resistance. The amount of residual stresses rose with increases in laser power, but at higher powers, increasing the scanning speed and spot diameter reduced stresses. At lower powers, the amount of residual stresses initially increased and then decreased with the scanning speed, with more significant changes occurring with larger spot diameters. Analyzing temperature and residual stress changes allowed us to improve the cladding layer quality, providing a theoretical basis for laser cladding on 42CrMo.

Enhanced chemical stability and H+/V4+ selectivity of microporous sulfonated polyimide via a triptycene-based crosslinker

Long durability of sulfonated polyimide in vanadium redox flow battery (VRFB) is urgently required to be solved. Herein, we synthesize a triptycene-based crosslinker and use it as chemical crosslinking point to modify a linear sulfonated polyimide for promoting its antioxidative stability. The novel triptycene-based cross-linked sulfonated polyimide (TCSPI-X) membranes featuring covalently crosslinked network display lower water uptake and swelling ratio than the commercial perfluorinated ionomer membrane (Nafion 117) membrane. More importantly, unnoticeable proton conductivity loss is appeared. We speculate this is because of the covalently crosslinking structure provides stable proton transportation channels, and the formation of micropores induced by rigid triptycene unit decrease proton migration resistance. In which, the TCSPI-5 (with 5 % molar triptycene unit) exhibit higher voltage efficiency as compared with the pristine membrane TCSPI-0. Combined with the excellent vanadium ions resistance, the TCSPI-5 reaches energy efficiency of 78 % at the current density of 140 mA cm−2. In addition, TCSPI-5 also shows high oxidation resistance even under strong acid and pentavalent vanadium ions (V5+) conditions. The above results suggest the potential of TCSPI-X membranes in VRFB application.

Excellent Performance of Mesoporous Carbon with High Crystallinity for Lithium Air Battery Cathode

1.IntroductionLithium-air batteries (Li-airs) have four times higher energy density by weight than current lithium-ion batteries because Li-air avail oxygen from outside of batteries. Therefore, Li-airs are expected as next generation batteries 1). Furthermore, specific capacity of cathode depends on specific pore volume of carbon materials in the cathode 2).On the other hand, a lifespan of Li-air is lower than conventional lithium-ion batteries because carbon materials in cathode is decomposed by lithium peroxide generated in discharge process.Therefore, carbon material with high oxidation resistance have been investigated for the cathode 3).In this study, mesoporous carbon materials “MPC” which have high specific pore volume and oxidation resistance were synthesized to be applied to cathode in Li-air. Furthermore, we investigated the relationship between an oxidation resistance of MPC and a cycle performance of the cathode in Li-air.2.ExperimentalMesoporous carbons were prepared by using the MgO template method 4). Phenol resin as carbon source was mixed with MgO. The mixture was heat-treated at 900 °C in N2 atmosphere to obtain carbon-MgO composite. The composite was rinsed by 1 mol L-1 H2SO4aq to remove the MgO from the carbon-MgO composite. Obtained MPC resulting from cleaning process (MPC-1) were heat treated at 1600, 1800, 2100, and 2400 °C (MPC-2, 3, 4, and 5). BET specific surface area (BET SSA), mesopore diameter, and pore volume of samples were calculated by BET and BJH methods with nitrogen adsorption measurements.Electrochemical performance of cathode in Li-air was measured under following conditions. Charge-discharge test was performed in a pure oxygen atmosphere at a current density of 0.4 mA cm-2 between 2.0 and 4.8 V until the specific capacity of cathode decreases to 3.2 mAh cm-2.3.Results and DiscussionCharacteristics of MPC-1, 2, 3, 4, 5 and Ketjen Black (reference sample) were represented in Table 1. BET SSA and total pore volume of MPC gradually decreased with heat treatment temperature up to 2100 °C, and it drastically decreased at 2400 °C. BET SSA and total pore volume of Ketjen Black decrease significantly due to a shrinkage of micropores and the other pores on the carbon by heat-treatment above 1600 °C. It is considered that MPC heat treated above 1600 °C have high BET SSA and total pore volume because 3D-structure of MPC derived from MgO template method mitigated the shrinkage of pores by heat-treatment. MPC-1 exhibit specific capacity comparable to Ketjen Black at 1st discharge process.MPC-1 has poor cycle performance despite having a large first discharge capacity. On the other hand, MPC-2 – 4 performed lower specific capacity and better cycle performance with heat temperature. From the results, there are obvious correlation among specific capacity, cycle performance, surface area and pore volume. MPC-5 exhibits the lowest specific capacity and cycle performance among MPC. It would come from decreasing of BET SSA and total pore volume by heat treatment at 2400 °C. Figure 1 shows the XRD patterns of MPC and Ketjen Black. A peak attributed to (002) of graphite was observed around 26° on the patterns of MPC-3 and 4. This result indicates that crystallinity of MPC was increased by heat-treatment above 1800 °C. Contrastly, there are no peak observed on the pattern of MPC-5. The result shows crystal structure of MPC is collapsed when heat treated at 2400 °C. From the results, it is turned out that crystallinity increasing of MPC would prevent degradation of cathode in Li-air during charge-discharge cycles.In this study, MPC-3 was the material with both high specific surface area and high crystallinity.Reference1) A.Kondri, M. Esmaeilirad, A. M. Harzandi, SCIENCE,379, 6631, 499-505, (2023).2) C. Tran, X. Q. Yang, and D. Qu, J. Power Sources, 195, 2057 (2010).3) Bae Y, Yun YS, Lim H-D, et al., Chem Mater.;28, 22: 8160-8169 (2016).4)T. Morishita, T. Tsumura, M. Toyoda, et al. Carbon 48, 10, 2690-2707 (2010). Figure 1

(Digital Presentation) Electrochemical Synthesis of Chromium Carbide Coatings on the Surface of Carbon Fibres in NaCl-KCl-CrCl3-Cr Melt and Study of Their Electrocatalytic Properties

Composite materials based on carbides of refractory metals are of exceptional interest in various fields of application. They have unique characteristics such as high hardness, catalytic activity [1,2], etc. They are widely used in industry due to their high corrosion and oxidation resistance at high temperatures. Chromium carbide can be produced in various ways, for example, the most common method of production is physical deposition from the gas phase (PVD coating). Other synthesis methods are not so popular, but they are also widely known (electron beam surfacing, plasma arc welding, etc.). These methods have both advantages and disadvantages. Refractory metal carbide coatings obtained by electrochemical methods in molten salts have a number of advantages, such as the possibility of obtaining homogeneous coatings on products with complex shape, low porosity of coatings, high adhesion to the substrate.Coatings of refractory metal carbides on a developed surface can also be used as electrocatalytic systems in reducing and oxidizing reactions. At the same time, the advantage of using electrocatalysis is the possibility of carrying out various reactions in a wide range of conditions from an extremely reducing environment to an extremely oxidizing one, the ability to control the route of the reaction by precisely adjusting the potential. Unlike common catalysis, electrocatalytic reactions do not leave reagents in the form of oxides, hydroxides or salts in the products. In electrochemical processes, an electron acts as a reducing agent, therefore high purity products are formed.The purpose of this study was the electrochemical synthesis of chromium carbide in molten salts on a substrate made of carbon fibres Carbopon-B-22, as well as the study of electrocatalytic properties of the obtained composites.To precipitate chromium onto a carbon substrate, a non-pressure transfer method in a molten equimolar mixture of NaCl and KCl containing 20 wt.% CrCl3, which is in contact with metallic chromium, was used. The synthesis of chromium carbides was carried out at temperatures of 1123 and 1223 K for 8-16 hours.To study the kinetics of the electrocatalytic decomposition of hydrogen peroxide on the surface of carbon fiber–synthesized chromium carbides, a method based on measuring the volume of the released oxygen gas was used [3,4]. The initial carbon fiber Carbopon-B-22 was used as the cathode, and a carbon fiber electrode with Cr3C2 and Cr7C3 chromium carbides coatings was used as the anode.In this study, two integral methods were used to determine the order of the hydrogen peroxide decomposition reaction: the substitution method (calculation of reaction rate constants according to equations for different reaction orders) and graphical (plotting of various concentration dependences on time and determining the linear dependence of one of them). The reaction rate constant was determined by the slope tangent of the straight line in the corresponding coordinates.The activation energy of the process was calculated based on experimental data obtained at different temperatures.References Stulov Yu., Dolmatov V., Dubrovskiy A. and Kuznetsov S. Electrochemical synthesis of functional coatings and nanomaterials in molten salts and their application // 2023. V. 13. 352.Dolmatov V.S., Kuznetsov S.A. Synthesis of Refractory Metal Carbides on Carbon Fibers in Molten Salts and Their Electrocatalytic Properties // Journal of The Electrochemical Society. V. 168. 122501.D. G. Miklashov, V. S. Dolmatov and S. A. Kuznetsov The currentless synthesis of tantalum and niobium carbide coatings on the carbon fibers and their electrocatalytic activity for the hydrogen peroxide decomposition reaction J. Phys.: Conf. Ser. 1281 012054.Yang G., Chen F., Yang Z. Electrocatalytic Oxidation of Hydrogen Peroxide Based on the Shuttlelike Nano-CuO-Modified Electrode // Inter. J. Electrochem. – 2011. – № 2012. – P. 1-6.

Development of Graphene Reinforced Composite Materials for Turbine Blades - A Review

The study highlights recent advancements in high-performance materials for turbine blades used in gas turbines and jet engines. Key research areas focus on developing materials that can withstand high temperatures (1400°C–1600°C) while resisting oxidation and corrosion, essential for enhancing efficiency and reducing emissions. Inefficiencies arise from the use of coatings and complex cooling systems, increasing the demand for materials with higher temperature tolerance. Weight reduction is another critical area of improvement, particularly in aviation applications. This paper reviews advancements in Intermetallic alloys, Metal Matrix Composites (MMCs), and Ceramic Matrix Composites (CMCs), with a specific focus on graphene composites due to their outstanding mechanical strength at elevated temperatures, lightweight composition, and high oxidative resistance. Additionally, the study explores recent developments in graphene-reinforced composites and Mo-Si-B-based alloys as potential alternatives to Ni-based super alloys, offering promising results for sustaining higher operating temperatures and enhanced performance under high-stress conditions.

Reusable SERS Platform of Femtosecond Laser Processed Substrate for Detection of Malachite Green.

This study presents the development of highly efficient Surface-Enhanced Raman Scattering (SERS) substrates through femtosecond (fs) laser processing of crystalline silicon (Si), resulting in mountain-like microstructures. These microstructures, when decorated with gold nanoparticles (Au NPs), exhibit remarkable SERS performance due to the creation of concentrated hotspots. The enhanced Raman signals originate from the excitation of localized surface plasmon resonance (LSPR) of the Au NPs and the multi-scale rough morphology of the Si substrates. Finite-element method simulations confirm the electromagnetic field enhancement in narrow gaps, supporting the experimental observations. The fabricated substrates show high uniformity, oxidation resistance, long-term stability, and exceptional reproducibility, making them ideal for molecular detection, especially in food safety applications. A remarkable enhancement factor (EF) of 1010 is attained in the detection of Malachite Green (MG), boasting a limit of detection (LoD) as low as 10-14 M. This underscores the immense potential of this technique for achieving highly sensitive and dependable SERS-based sensing capabilities.

Si modified aluminide coatings on a Ni-base superalloy prepared using Al-Si plasma irradiation: Growth mechanism and oxidation behavior

The growth mechanism and high temperature oxidation behavior of Si-modified aluminide coatings prepared on a Ni-base single crystal superalloy DD98M using vacuum plasma irradiation were investigated. The growth of the coatings under plasma irradiation was much faster than thermal diffusion-controlled process. The coatings comprised an aluminide outer zone, where Si existed as solid-solute, and an inter-diffusion zone where silicide particles precipitated in aluminide matrix. The crystalline structures of the aluminides were found dependent on the irradiation power. β-NiAl was formed at higher irradiation power while δ-Ni2Al3 was formed at lower irradiation power. The β-NiAl coatings had higher oxidation resistance than the δ-Ni2Al3 ones usually, with an exception of one β coating which was prepared at the highest substrate bias which underwent severe internal oxidation. The presence of numerous voids in the oxide scale of Ni2Al3 may be related to the large number of Kirkendall voids present in the as-prepared coating.

Heterogeneous multilayered delamination of thermally grown oxide accelerating spallation of thermal barrier coatings

Long lifetime of thermal barrier coatings (TBCs) is limited by the localized thermally grown oxide (TGO) accumulation. Herein, the heterogeneous multilayered delamination mechanism of TGO is revealed. TGO cracking preferentially occurs at the peak of bond coat due to mismatch and extends toward the flank region under TGO growth. The thinner sublayer after first delamination is mainly attributed to loss of ceramic constraint. The delamination accumulation increases the YSZ crack driving force and provides a fast propagation channel for YSZ crack to pass through TGO. These results provide a guidance for the development of advanced TBC with higher oxidation resistance.

Spinodally reinforced W-Cr fusion armour

Here, we introduce a discontinuous spinodal reinforcement strategy in the novel candidate plasma facing material (PFM) of tungsten-chromium alloys. Thermal ageing of a W-34wt%Cr alloy at 1250 °C causes nano-scale lamellae 200–600 nm to form heterogeneously from grain boundaries, which progressively grow into the matrix fully, then coarsen to 1–2 µm after 100 h. The dual-phase microstructure confers exceptional high temperature compressive strength, maintaining 900 MPa at 1000 °C - double that of polycrystalline tungsten. Further, the chromium alloying promotes a dense oxide scale that confers a 2 orders of magnitude improvement in resistance against oxidation at 1000 °C compared to W, which is an important consideration for PFMs under loss of vacuum accident conditions. The dual-phase W-Cr alloy concept's combination of high strength and oxidation resistance represents a new scalable alternative to tungsten, with wide scope for further alloying and process optimisation.

Synthesis and evaluation of thermal and optical properites of Fe2AlB2 phase alloy for thermal control in space applications

Ternary laminated Fe2AlB2 alloy holds its significance in displaying high strength, damage tolerance, oxidation and radiation cracking resistance. It is synthesized through a pressureless sintering route from elemental powders. Synthesis of Fe2AlB2 is studied from two different molar ratios (2/1/2 and 2/1.5/2) and three different sintering temperatures (1100°C, 1150 °C and 1200 °C). Phase analysis is carried out through an x-ray diffractometer and scanning electron microscopy (SEM). In addition, thermal decomposition, thermal conductivity and absorbance spectra are examined. Fe2AlB2 begins to decompose at 1169 °C into borides and aluminides. Thermal conductivity and diffusivity of Fe2AlB2 decreases with increase in temperature. Lower solar reflectivity and high thermal emittance of Fe2AlB2 implies the thermal control and optical behavior that can be expected for extreme space environments.

High temperature oxidation mitigation efficacy of Al2O3 and Ni-20Cr ceramic coating on boiler steel application

The primary reason of degradation and failure of many products used for high temperature applications are oxidation. Protective coatings are employed to increase the component resistance to oxidation. In the present research work, Al2O3 and Ni-20Cr were applied as coatings on SAE431 steel using a detonation gun spraying technique. At 800 °C in air with 50 cycles of heating and cooling, the oxidation behavior of uncoated and coated SAE-431 boiler steel was analyzed. Ni-20Cr coating on SAE431 boiler steel exhibits approximately 25.44 % higher oxidation resistance and the Al2O3 coating on SAE431 boiler steel exhibits approximately 32.22 % higher oxidation resistance compared to uncoated SAE431 boiler steel. After oxidation at 800 °C, the SAE431 boiler steel coated with Ni-20Cr displays prominent peaks of the Cr2O3 and Ni phases, with some minor phase of NiO. The NiO phase is observed to be less intense than Cr2O3 and Ni phases. After oxidation at 800 °C, Al2O3 coated SAE431 boiler steel exhibited strong peaks of ƞ-Al2O3 and δ-Al2O3 phases. The X-ray diffraction investigation also reveals the existence of the α-Al2O3 phase. According to our findings, based on weight change data, Ni-20Cr and Al2O3 coated boiler steel provided higher oxidation resistance than the uncoated SAE431boiler steels. The enhancement in the oxidation resistance of boiler steel can be attributed to the formation of nickel, chromium and aluminum oxide inert layer which is evident from the XRD patterns also. Exploration throughout global survey has been already done and it was found that not much work has been done on the high-temperature behavior of Ni-20Cr and Al2O3 coatings. The data obtained from the study will be helpful in examining the viability of using these coatings on boiler tubes.

Preparation and erosion resistance of SiC-based ceramic-PCM sensible-latent heat composite heat storage materials

Alloy phase change materials (PCM) are key materials in latent heat storage systems for solar thermal power generation, however, their application is limited by the high corrosion and oxidation problems of alloys. To reduce the erosion problem of alloy PCM, SiC-based ceramic encapsulated flake graphite (EG) modified Al-Cu28-Si6 alloy was used to successfully prepare composite PCM with high compatibility and oxidation resistance. Adopting static erosion test method, the composite PCM was subjected to 50 thermal cycles (25–1000 °C holding time of 10 h was recorded as 1 cycle). The results showed that SiC-based ceramics have excellent corrosion resistance to composite PCM with 10 wt% EG added, which due to the excellent reticulation and encapsulation of EG. Based on the Young-Laplace equation and the contact angle, the erosion resistance mechanism of silicon carbide ceramic alloys has been revealed. SiC-based ceramic-PCM sensible heat-latent heat composite heat storage material was expected to be used for high-temperature heat storage in solar thermal power generation.

Developing advanced CrSi coatings for combatting surface degradation of N-type (Zr,Ti)Ni(Sn,Sb) and P-type (Zr,Ti)Co(Sn,Sb) half Heusler thermoelectric materials

In this study, advanced oxidation-protective CrSi coatings were developed and deposited on N-type (Zr,Ti)Ni(Sn,Sb) and P-type (Zr,Ti)Co(Sn,Sb) thermoelectric (TE) materials using an environmentally friendly closed field unbalanced magnetron sputtering PVD system. The oxidation behaviour of the CrSi-coated and uncoated samples was evaluated through static oxidation tests at 500 °C and 600 °C for 10h and 50 h, respectively. In addition, the samples were exposed to cyclic oxidation tests between 25 °C and 500 °C for 10, 30 and 50 cycles, with each cycle consisting of 1h of oxidation at 500 °C, to examine the coating ability to withstand thermal shock, which is involved in the service of TE devices. The surface morphology, cross-section layer structure, elemental distribution and phase constitution were analysed using scanning electron microscopy (SEM), energy dispersive spectroscopy (EDX) and X-ray diffraction (XRD). The mass gain after the oxidation tests was measured and calculated for each sample to study the oxidation kinetics. The uncoated samples exhibited a considerable amount of oxidation, leading to change in the surface morphologies, and the formation of alternated layers including oxide products (Zr(Ti)O2, SnO2) and Ni3Sn4 compound for the N-type and (Zr(Ti)O2, SnO2, Sb2O4) and CoSb compound for the P-type material, after static and cyclic oxidation tests. The experimental work in this study has, for the first time, demonstrated that the CrSi coatings developed with very high thermal stability and oxidation resistance can effectively protect both the N-type and P-type materials from oxidation and sublimation even during cyclic oxidation tests. The strong affinity of Cr and Si to oxygen can trap oxygen, retard its inward diffusion and thus protect the TE material substrate from oxidation. This finding could pave the way towards the further development of long-life high-performance TE generators and devices, thus contributing to the net zero target.

Research progress of highly wear‐resistant and oxidation‐resistant polymer acetabular cup prosthesis

AbstractThe polymer‐based acetabular cup prosthesis, a vital component of hip replacement surgery, significantly contributes to the recovery of patients afflicted with osteoarthritic conditions. Nevertheless, the current clinical usage of polymer acetabular cup prostheses commonly encounters the challenge of balancing wear resistance and oxidation resistance, significantly impacting both their lifespan and patients′ quality of life. Consequently, researchers have persistently enhanced the attributes of polymer acetabular cup prosthetic materials. These enhancements, including irradiation and filler modifications, are intended to concurrently bolster both the wear and oxidation resistance of the prosthesis materials. This comprehensive approach aims to address wear‐associated clinical complications like osteolysis and oxidative brittleness, ultimately extending their in vivo service life. For this reason, this paper retrospectively discusses the progress of research on the modification of polymer acetabular cup prosthesis materials for high wear and oxidation resistance and explores potential design methods for optimising artificial acetabular cup materials, with a view to providing new ideas for extending the service life of artificial joint implants.

Preparation of high-performance water-based ink from acrylic-modified rosin resin

This study focuses on the preparation of a water-based ink binder using acrylic-modified rosin polyethylene glycol ester (ROPEGE). This binder is characterized by a low acid value (12.23 mg NaOH/g), low viscosity (5.40 mPa s), high fixed content (92.40 %), and excellent printability. Compared to reported water-based inks, the inks derived in this study exhibit higher fixed content (resulting in lower VOC emissions), low acid value (indicating high oxidation resistance), and low viscosity (enhancing print quality). The individual effects of emulsifier type, emulsifier content, initiator type, initiator content, acrylic acid content, and dispersant content are analyzed as single factors. The optimal formulation is achieved by selecting specific components: emulsifier PEG-400 (40 wt%/ROPEGE), initiator potassium persulfate (10 wt%/ROPEGE), functional monomer acrylic acid (10 wt% of ROPEGE), and wetting and dispersing agent OT-75 (10 wt%/ROPEGE). The enhancement of the water-based ink formulation is accomplished through the use of acrylic-modified rosin resin (AMRR) as the binder, dimethyl silicone oil as the defoamer, and malachite green as the pigment.

Fundamental structural study of hexagonal boron nitride (h-BN) and boron nitride nanotube (BNNT) at low and high temperatures

The molecular structure stability at low and high temperature is important for an industrial application. The boron nitride-based materials, such as hexagonal boron nitride (h-BN) and boron nitride nanotubes (BNNTs), have been interested due to their high oxidation resistance and thermal stability. In this study, ex-situ and in-situ characterization techniques (e.g., Raman spectroscopy, X-ray Diffraction (XRD), and Fourier-transform infrared spectroscopy (FTIR)) were applied to investigate the structural change of BNNT and h-BN at high (up to 800 °C) and low (down to -50 °C) temperatures. The Raman spectroscopy results showed that at high temperatures (800 °C), h-BN exhibited a significant red shift under both inert and oxidizing conditions, while BNNT showed no peak shift, indicating its more stable structural resistance compared to h-BN. Both h-BN and BNNT showed no peak shift after cooling to low temperatures (-50 °C). Stability of h-BN and BNNT up to a high temperature of 800 °C was revealed from the thermogravimetric analysis (TGA) and FTIR spectroscopy results. The FTIR results also indicate that under oxidizing conditions, heating h-BN results in the formation of more hydroxyl groups compared to BNNT. The in-situ XRD results showed a greater magnitude of lower 2θ shift with increasing temperatures for h-BN compared to BNNT. Additionally, there was a more significant increase in FWHM values with respect to temperatures for h-BN than BNNT regardless of the sample under inert or oxidizing conditions. The characterization results from this study indicate that BN-based materials, especially BNNT, are suitable candidates for high temperature chemical reaction applications.

A comparative study on the structure and properties of TiAlSiN coatings deposited by FCVA and HiPIMS

The TiAlSiN coating has garnered significant interest due to its exceptional hardness, high oxidation resistance temperature, robust film-substrate bond strength, excellent wear resistance, and superior thermal stability. The energetic ion beam technology has emerged as a potent method for fabricating thin films. In this study, TiAlSiN films were deposited utilizing magnetic filtered cathode vacuum arc (FCVA) and high power pulsed magnetron sputtering (HiPIMS), and their respective structures and properties were meticulously investigated and contrasted. Upon comparative analysis, it was observed that the elemental composition of the FCVA films underwent a pronounced change with the same. Depending on the desired film thickness, the deposition rate of the FCVA system was found to be superior over the same duration. The crystallographic structure of the films fabricated by both systems predominantly featured an fcc-(Ti,Al)N phase. Notably, at an N2 flow rate of 40 sccm, the film deposited via HiPIMS demonstrated remarkable hardness (27.04 GPa), an elevated H/E* ratio (0.103), and superior wear resistance (7.24×10−6 mm3/N∙m). The films produced by these two deposition methods exhibited discernible differences and clear trends in hardness, adhesion strength, and tribological properties. This research provides a valuable reference for selecting the most appropriate deposition process and parameters based on the desired attributes of the coatings.