Al2O3 Ceramic Particles Research Articles

Evaluation of Micro Hardness of Magnesium Alloy Coated with ZnO and Al2O3

Magnesium and its alloys have wide range of application in automobile and aircraft industries because of their excellent mechanical properties i.e. high strength to weight ratio, availability and good castability etc. However, some challenges occur in using magnesium in aquas service applications, due to its highly reactive nature and low tribological properties such as low wear and corrosion resistance. In this work an experimental study has been done on uncoated and ceramic coated AZ91 alloy to compare hardness and wear properties of both. The coating was applied on varying weight percentage of ZnO and Al2O3ceramic particles. The effect of presence of ceramic particles on the surface of substrate was studied using scanning electron microscope. Micro Vickers hardness test and wear tests were conducted on the samples, and it was found that coating of ceramic particles made the surface harder and wear resistant as compared to the uncoated Mg alloy. Contribution of Al2O3 particles plays an importantrole in increasing the hardness and wear resistance of coated surface. A decrease of 84% in coefficient of friction, increase in wear resistance by 99% and increase in micro hardness by 92% was reported for Al2O3 coated sample as compared to the uncoated surface.

Enhancing mechanical and corrosion properties of GO and Al2O3 reinforced Cu composite coatings

Despite their significant functions and properties, the performance characteristics of Al2O3 ceramic particles and graphene oxide (GO) within hybrid copper composite coatings have been seldom investigated. This study successfully fabricated a Cu-GO- Al2O3 composite coating featuring fine particulate spherical network-like structures on St37 low carbon steel using an ultrasonic-electroless coating method. The effects of Al2O3-decorated graphene oxide hybrid reinforcement on the texture and nanomechanical properties of the copper matrix were examined. The tribological performance of the Cu-GO- Al2O3 composite coating under dry sliding conditions was evaluated, and the wear mechanism was investigated in detail. Results demonstrate that the Cu-GO- Al2O3 composite coating effectively reduces the wear rate and friction of the GO/ Al2O3 hybrid reinforced composite coating. Potentiodynamic polarization tests indicated that the Cu-GO- Al2O3 composite coating exhibits higher corrosion resistance compared to the copper matrix. The enhanced mechanical, tribological, and corrosion properties of the Cu-GO- Al2O3 composite coating are primarily attributed to: (i) the fine particulate spherical network-like structure; (ii) the synergistic effect of the GO and ceramic particle hybrid with a decorated structure; (iii) the formation of graphene oxide/ Al2O3 nanorolls in tribofilms and the excellent self-lubrication properties of graphene oxide. The Cu-GO- Al2O3 composite coating significantly improves the frictional and electrochemical properties of the copper matrix, offering new perspectives for next-generation electrical contacts and nanoelectromechanical systems.

Repairing Al7075 surface using cold spray technology with different metal/ceramic powders

Cold spray process is essentially a coating technique as well as used in repair applications. This method is a low-temperature solid-state process. In this study, the damaged surface of Al7075 was repaired by low pressure cold spray method with Ni-Zn-Al2O3, Al-Zn-Al2O3, Al-Al2O3, Ni-Al2O3, and Zn-Al2O3 metal/ceramic feedstock powders. Microstructure examination, microhardness measurements, tribological experiments, and tensile tests were conducted on the repaired samples and compared with Al7075. The repaired regions exhibited a composite microstructure characterized by the presence of Al2O3 ceramic particles with high hardness dispersed within a metal matrix composed of Al, Ni, Zn, Ni-Zn, and Al-Zn. This composite structure was attributed to the interlocking mechanism of cold spray. The highest hardness value was measured in the repaired area using Ni-Al2O3, which is approximately 1.28 times higher than that of Al7075 alloy. According to the dry sliding test, the wear performance of all repaired specimens was superior to that of Al7075. The wear resistance of samples repaired with Ni-Al2O3 and Ni-Zn-Al2O3 increased approximately 7.1 and 5.8 times, respectively, compared to Al7075. The specimens repaired with Ni-Zn-Al2O3 feedstock powder showed the most similar results in tensile and yield strength values to Al7075 to the tensile test.

Effects of Al2O3 and Cr2O3 on the microstructure and properties of Mo alloys prepared via vacuum sintering

The dilemma of strength and ductility of Mo alloy at ultra-high temperature (above 1300 °C) limits its application in space reactors and other high-temperature environments. Single oxide enhancement has been unable to meet these use requirements. In this research, a strategy of synergistic reinforcement of Mo alloys with nanosized Al2O3 and Cr2O3 ceramic particles was proposed. A 300−400 nm Mo alloy powder was prepared by liquid‒solid doping, and in situ self-generated nanosized oxides were obtained. The grain size of vacuum sintered Mo alloy was very fine, at only 5.3 μm, which was one tenth of the particle size of commercial Mo alloy. Al2O3 and Cr2O3 particles were distributed in the grains of the Mo matrix, which effectively prevented the growth of Mo grains during vacuum sintering and reinforced the Mo alloy. The maximum flow stress of the Mo–Al2O3–Cr2O3 alloy reached 367 MPa at 1000 °C/1 s−1, which was better than that of the single-oxide reinforcement. The ultimate tensile strength (UTS) of the Mo–Al2O3–Cr2O3 alloy was 862 MPa, which was twice that of pure Mo. The preparation process is simple and available for industrial production. Synergistic strengthening of multiple oxides will be the best strategy for strengthening refractory alloys in the future.

Microstructure and high-temperature oxidation resistance of in-situ Al2O3 reinforced AlCrFeTiV high-entropy alloy with boron microalloying

In this study, the effect of boron (B) on the microstructure and high-temperature oxidation resistance of AlCrFeTiV high-entropy alloy (HEA) coatings were investigated via laser cladding on Ti-6Al-4 V. The study findings indicate that AlCrFeTiVBx (x=0, 0.5, and 1 at%) HEAs coatings mostly comprise BCC solid solution phase, TiO2 and Al2O3 ceramic particles, which formed by oxygen (O) in the air reacts with Titanium (Ti) and Aluminum (Al) of coatings. Besides, the introduction of minor B should effectively reduce the formation of TiO2. Increasing the B content, significantly promoted the high-temperature oxidation resistance of HEAs coatings at 900 °C for 50 h. When x = 1, the coating exhibits the best high-temperature oxidation resistance. Furthermore, the oxidation mechanism of the coating was studied using first-principles calculations, and further investigation was utilized on the charge transfer of oxygen adsorbed on the BCC (1 0 0) surface.

Impact-abrasive wear property of ZrO2 toughened Al2O3 ceramic particles reinforced high manganese steel matrix composites

ZrO2-toughened Al2O3 (ZTA) ceramic particle–reinforced high manganese steel (HMS) matrix composites are a promising class of wear-resistant structural materials for various purposes such as mining. In this study, millimeter-scale ZTA/HMS composites were prepared by cast infiltration method. Using SEM, EPMA, TEM, nanoindentation, a microhardness tester, and an impact-abrasive wear machine, the microscopic characteristics of interfacial layers, work-hardening behaviors, impact-abrasive wear properties, and wear failure mechanism were investigated. The results show a smooth and continuous interfacial layer between ZTA and the matrix. This layer is dominated by an amorphous structure, and the hardness and modulus of the interfacial layer reached 6 and 200 GPa, respectively. The relative wear resistance of the composites under impact (energies of 2–5 J) was between 2.17 and 0.59, and the depth of the work-hardening layer amounted to 0.95–2.95 mm. The wear failure mechanism of the composites was as follows: at a low impact energy (2 J), micro-cutting, grooving, fatigue spalling, and wedge formation occurred. When the impact energy was increased to 5 J, the wear mechanism of the composites was dominated by the breaking and shedding of the ZTA particles. This study has practical importance because it is based on the problems and needs of composites in actual production.

Study on the mechanism of the effect of biomass ash on the erosion and adhesion behavior of Al2O3 ceramic particles

Biomass coupled with photothermal gasification technology is a new type of technology using heat carriers to transfer the solar energy to supply heat, and directs the solar energy absorbed by the heat carrier to provide a continuous heat source for biomass gasification. To investigate the erosion and adhesion mechanism of cornstalk ash (CSA) on heat carriers (Al2O3 ceramic spheres) during heat transfer, ash fusion temperature analyzer (AFTA) and FactSage thermodynamics software were used to analyze the effect of alumina addition over CSA sintering from the perspective of melting point, high-temperature heating stage coupled with optical microscope system (HTSOM) was used to observe of the adhesion behavior of CSA on the surface of ceramic spheres, X-ray diffractometry (XRD) and Laser-induced breakdown spectroscopy (LIBS) as well as SEM-EDS (Scanning electron microscope - Energy dispersive spectrometer) were used to detect the mineral evolution from both matter and elements. The results showed that the sintering stage (FT-DT) of CSA extended by adding more than 5 wt% of Al2O3 to CSA. Furthermore, it was found that as the temperature increased, Al-containing minerals such as pyroxene and chalcocite were formed, which indicated the CSA began to erode the heat carrier by mineral evolution on the surface of ceramic spheres. At high temperatures (>1200 ℃), CSA completely melted to form a liquid phase that wrapped around the surface of the ceramic spheres, which played a role in insulation layer during the cooling process to reduce the cooling rate of the surface of the ceramic sphere, resulting in more evident slagging problem. At the same time, the K and Ca element in the CSA was captured by ceramic spheres. The mineral transformation between the ceramic spheres and CSA was simulated by FactSage thermodynamic software, and it was found that the addition of Al2O3 resulted in the increase of the ash melting temperature and the formation of Al-containing mineral matters such as nepheline and augite.

Water-based dual polymer ceramic-coated composite separator for high-energy-density lithium secondary batteries

A simple, eco-friendly, and effective additive-free technique for stabilizing a coating slurry, using alumina (Al2O3) inorganic particles and aqueous dual polymers—sodium carboxymethyl cellulose (CMC) and polyvinyl alcohol (PVA) is developed. The slurry preparation process is optimized by determining the polymer binders (CMC/PVA) content in the ceramic slurry and studying the interaction between the polymer binders and Al2O3 ceramic particles by changing the mixing order of the slurry components. CMC effectively controls the viscosity of the slurry to maintain a stable slurry dispersion. In contrast, PVA significantly influences the formation of a uniform ceramic coating layer on the polyethylene (PE) separator. This results in a synergistic effect to produce an optimal ceramic-coated composite separator (CCS). Compared to the bare PE separators, the prepared Al2O3 CCSs display improved physical properties, such as high adhesion strength of the ceramic coating layer, thermal stability, electrolyte wettability, and increased ionic conductivity. Moreover, the CCSs exhibit enhanced electrochemical performance. Half cells (LiMn2O4/Li metal) comprising CCSs retained 96.5% (144.8 mAh g−1) of the initial discharge capacity even after 200 cycles, while bare PE separators lose their capacity rapidly after 150 cycles, retaining only 22.62% (33.5 mAh g−1) at the 200th cycle.

Ultrasonic vibration effect in the development of Al/CCLW/alumina metal matrix composite to enhance mechanical properties

This study represents the enhancement in mechanical, metallurgical, and thermal properties of composite synthesized by ultrasonic vibration effect. Collagen powder in the form of Cr2O3 was derived from chrome-containing leather waste (CCLW). Collagen powder and Al2O3 ceramic particles have been used to reinforce the development of an AA6061 aluminum alloy-based composite. Results showed that the composite developed under the ultrasonic vibration process showed better results by adding only 7.5% reinforcement particles (3.75% collagen + 3.75% Al2O3) to the matrix material as compared to the composite developed by the stir casting technique. The tensile strength and hardness were improved by about 40.41% and 44.27%, respectively when the composite was developed under the ultrasonic vibration effect. The compressive strength of composite material developed under the ultrasonic vibration effect was also improved by about 13.80% concerning the base material.

Implantation of tantalum ions into a dielectric coating synthesized by electron-beam evaporation of aluminum oxide ceramic in the forevacuum pressure range

We describe our investigations of the electrophysical properties, phase composition and structure of Al2O3 ceramic particles in coatings formed by electron-beam evaporation of alumina ceramic and modified by implantation of tantalum ions. The ceramic coatings were synthesized in a helium atmosphere in the forevacuum pressure range of 1–10 Pa, at characteristic temperatures of beam target and substrate about 2500 and 250 Celsius, respectively, at a deposition rate of 500 nm/min. Ion implantation was performed using a metal ion source based on a vacuum arc discharge, at pressure of order 10−4 Pa; the mean tantalum ion energy was 90 keV and the implantation doses investigated were 1 × 1016, 5 × 1016, and 1 × 1017 ion/cm2. The original and modified ceramic coating samples were studied using a transmission electron microscopy technique. Measurements of the surface resistivity showed that the treatment of coatings by high-energy tantalum ion implantation leads to increase in specific resistance and decrease in sheet resistance.

Micromechanical damage analysis of Al-Al2O3 composites via cold-spray additive manufacturing

3D micro-scale finite element (FE) models were developed to analyze the stress-state-dependent initiation and growth of failure of cold-sprayed additively manufactured (CSAM) Al-Al2O3 composites. Informed by experimental particle size distributions and porosity measurements, representative volume elements (RVEs) were generated by Digimat. Stress-state-dependent constitutive models for the Al matrix and Al2O3 ceramic particles were implemented by VUMAT subroutines in ABAQUS/Explicit FE solver. For the first time in the literature on metal–ceramic composites, the microscale failure mechanisms involving matrix ductile failure, particle cracking, and matrix/particle debonding were all quantified based on the crack volume fraction, the fraction of cracked particles, and the fraction of fully debonded interfacial nodes, respectively. The FE model was quantitatively and qualitatively validated by the experimental data for Al-46 wt% Al2O3 under quasi-static uniaxial compression. The validated model was used to investigate the effect of the particle content and size on the material behavior subjected to different stress states. The results revealed that the failure mechanisms are activated in a specified order across different stress states: I. matrix/particle debonding, II. particle cracking, and III. matrix ductile failure. The material ductility observed under compression/shear vanishes under tension due to the earlier activation of debonding and the faster growth (∼ 10 times) of the particle cracking mechanism. Additionally, it was shown that the particle size minimally affects the material strength and flow stress under shear which is likely related to the low load transfer effect through the interfaces. The novelty of this work stems from the provision of a better understanding of the stress-state-dependent evolution of failure mechanisms through a systematic quantification framework whose outcomes have implications for the design of better-performing Al-Al2O3 composites via control of the evolution of failure mechanisms and developing micromechanism-based constitutive models for CSAM metal–ceramic materials.

Influence of polyvinyl alcohol coated porous Al2O3 ceramic waste particles on cement properties in geothermal applications

To improve the low strength of the existing geothermal temporary sealing cement (GTSC) and figure out the influence of PACW on cement performances in geothermal applications, the hard porous Al2O3 ceramic waste (PACW) was introduced into oil well cement. The water-soluble PVA was coated on PACW particles to wrap the porous ceramic at relatively low temperature for geothermal drilling, and dissolve in water at ≥ 90 ℃ for hot water flow. The compressive strength, hydrates, pore structures and interface transition zone of cement with raw or modified PACW were tested. The results showed that 10% raw and modified PACW enhanced the compressive strength of oil well cement by 57.69% and 60.31% respectively, during the 90 ℃ water immersing. For the cement containing 10% raw and modified PACW, thermal weight loss related to degradation of hydrates and CH increased, meso pores fraction rose to 52.73% and 51.93 % respectively, and the deeper etch pits on surfaces of the mineral suggested the promoting effect of PACW on cement hydration. The promoted cement hydration and formed hydrates with their filling effect contributed to the cement strength enhancement. As the thermal weight loss attributed to AFm increased after immersion, the thermodynamic parameters of the possible transformation reaction of AFt to AFm were calculated. The standard molar Gibbs free energy change of the reactions are negative, and microstructure images showed that the PACW surface was covered by lots of flaky AFm crisscrossed with large hexagonal AFt crystals, proving that the alumina in PACW participated in and promoted the transformation of AFt to AFm. In addition to reservoir protection, simplifying construction procedures and reducing the time cost of geothermal development, the high-strength GTSC will further strengthen the hole wall and reduce the risk of borehole collapse.

Incorporation of Al2O3 and ZrO2 ceramics to AZ31 magnesium alloys composite coating using micro-arc oxidation method

In this research, a composite coating with Al2O3 and ZrO2 particles have been applied on AZ31 magnesium alloy by micro-arc oxidation (MAO) technique. The alkaline electrolyte included a constant based composition and different composition of the Al2O3 and ZrO2 additives. Microstructure observations reveal that the surface pores of composite coating reduced during addition of ZrO2 and Al2O3 ceramic particles. The hardness of coating increased from about 380 for non-added to 620 MPa for Al2O3+ZrO2 added coating and wear rate reduced about 8 times. Wettability of the coating increased by incorporation of Al2O3 and/or ZrO2 particles while, Al2O3 is more effective than ZrO2. Addition of the ceramic particles enhanced the hydrophilicity properties of surface in wettability test and a contact angle of 43° was obtained for coating including Al2O3+ZrO2. The antibacterial properties of MAO coatings showed that S. aureus bacterium is more sensitive to the zirconia and alumina particle than S. typhimurium bacterium after 24 h of incubation.

Effect of strength and toughness of ceramic particles on impact abrasive wear resistance of iron matrix composites

The wear resistance of ceramic particle reinforced metal matrix composites is closely related to the properties of ceramic particles. In this study, three kinds of ceramic particle (with 30 % volume fraction) reinforced iron matrix composites (Al2O3/Fe45, ZTA(Zirconia toughened alumina ceramic particles)/Fe45 and ZrO2/Fe45) were prepared by powder metallurgy method. The mechanical properties, impact abrasive wear resistance and impact abrasive wear mechanism of the composites were studied, and the phase transformation of ceramic particles in the composites was analyzed. The results show that the elastic modulus and hardness of ZTA/Fe45 composite are between Al2O3/Fe45 and ZrO2/Fe45, which are 248.5 GPa and 13.3 GPa, respectively. The ZTA/Fe45 composites exhibit a better impact wear resistance than the other two composites. The impact abrasive wear resistance of the three kinds of composites is positively correlated with the product value of fracture toughness and hardness (H·KIC) of ceramic particles. The wear mechanism of the Fe45 matrix of the composite is micro-furrow and plastic deformation. The brittle fracture and spalling of Al2O3 ceramic particles occur after impact abrasive wear, forming spalling pits and accelerating the wear of Al2O3/Fe45 composites. ZrO2 ceramic particles lead to easy removal from the Fe45 matrix due to lower hardness after impact abrasive wear. ZTA ceramic particles protruded from the surface of the Fe45 matrix after impact abrasive wear. On the surface of ZTA particle, the irregular protuberant steps morphology are formed by SiO2 abrasive impact and tangential wear. The ZTA and ZrO2 ceramic particles in the worn surfaces of the composites undergo t-ZrO2 to m-ZrO2 phase transformation during the impact wear, and the t→m phase transformation content is related to the impact energy. The amount of phase transition increases with the increase of impact energy, When the impact energy is higher than 2J, the amount of phase transition tends to be stable. Under the same impact energy, the amount of t→m phase transition in ZrO2 particles is much lower than that in ZTA. The t→m phase transformation increases the toughness of ZTA particle，improving the impact abrasive wear resistance of ZTA/Fe45 composite.

Investigation of moisture vapor permeability and thermal comfort properties of ceramic embedded fabrics for protective clothing

This study examined the water and moisture vapor permeable and thermal wear comfort of different ceramic imbedded fabrics for workwear protective clothing, and the results are discussed in terms of the thermal radiation and the emissivity characteristics of these fabrics. The water and moisture vapor permeable and thermal wear comfort properties of the ceramic-imbedded fabrics incorporating aluminum oxide (Al2O3)/graphite, zinc oxide (ZnO)/zirconium carbide (ZrC) and ZnO/antimony tin oxide (ATO) were superior to those of the regular polyethylene terephthalate (PET) fabrics due to the greater heat emission of the ceramic-imbedded fabrics. Of three ceramic imbedded fabrics, ZnO/ATO-imbedded fabric exhibited poorer water absorbing and drying properties than those of the Al2O3/graphite and ZnO/ZrC ceramic-imbedded fabrics. The heat retention rate and breathability were also inferior to those of the Al2O3/graphite and ZnO/ZrC ceramic-imbedded fabrics, which were due to the lower far-infrared (FIR) emissivity of the ZnO/ATO-imbedded fabrics. Summarizing the water and moisture vapor permeable and thermal wear comfort properties with heat release characteristics of the different ceramic imbedded PET fabrics, Al2O3 and ZrC ceramic particles imparted a good wear comfort characteristics with superior heat release property, whereas, the ZnO and ATO ceramic particles imbedded fabrics exhibited inferior water and moisture vapor permeable and thermal wear comfort due to the lower heat release of ZnO particles and the heat shielding effect of ATO particles, which is supposed to impart an uncomfortable feeling while wearing workwear protective clothing in cold/dry environments in cold weather regions. These findings suggest that ZnO and ATO particles need to be mixed with ZrC and Al2O3 particles in the yarns to enhance wear comfort of workwear protective clothing.

Fabrication of Multiscale-Alumina Particles Reinforced Copper Matrix Composites with High-Energy Ball Milling and Hot Pressing

Cu-Al2O3 composite materials combining the good electrical of copper matrix and the high hardness of Al2O3 ceramic particles show great performance in electronics, electrical sliding contacts fields. However, the relationship of a dilemma between strength and ductility has become a limitation for the development of copper matrix composites. The previous works indicated that fine grain powders can improve interfacial bonding between the copper matrix and Al2O3 particles to further enhance strength while maintaining ductility. In the present work, the multiscale-alumina particles reinforced copper matrix composites were successfully fabricated by mixing high-energy ball milling and consolidation of hot-press sintering. SEM and TEM were used to observe the powder morphology and microstructure of Cu-Al2O3 composites. The results show that the reinforcing phase Al2O3 particles are uniformly dispersed in the copper matrix, which improves interfacial bonding between the copper matrix and Al2O3 particles. Especially, the micro Al2O3 particles play an important role in achieving an excellent tradeoff of strength and ductility in the Cu-Al2O3 composite. In addition, the microhardness of Cu-Al2O3 composites can be greatly improved by using the high-energy ball milling and hot-press sintering process. The research idea of this paper can provide a reference for other composite materials that need to improve mechanical properties.

Microstructure and Mechanical Properties of Novel Lightweight TaNbVTi-Based Refractory High Entropy Alloys.

A series of novel lightweight TaNbVTi-based refractory high entropy alloys (RHEA) were fabricated through ball-milling and spark plasma sintering (SPS). The reinforced phase of TiO precipitates were in-situ formed due to the introduction of Al2O3 ceramic particles. The RHEA with 15% Al2O3 exhibits a high compressive yield strength (1837 MPa) and a low density (7.75 g/cm3) with an adequate ductility retention. The yield strength and density are 32% higher and 15% lower, respectively, compared to the RHEA without Al2O3 addition. The specific yield strength (237 MPa cm3/g) of the RHEAs is much higher than that of other reported RHEAs, and is mainly ascribed to the introduction of high volume fraction of Al2O3 additives, resulting in solid solution strengthening and precipitation strengthening. Meanwhile, the ductile matrix is responsible for the good compressive plasticity.

Fabrication and wear property of NiCo coated ZrO2–Al2O3 ceramic particles reinforced high manganese steel-based composites

In this work, the nickel-cobalt layer was used as a medium to improve the interfacial bonding of ZrO2–Al2O3 particles (ZTAP) reinforced high manganese steel-based composites. The nickel-cobalt layers on the surface of ZTAP ceramics are prepared by electroless deposition in the sulfate solutions. The formation mechanism, morphology evolution and elemental composition of the NiCo coating were investigated by varying the plating temperature, plating time and sulfate concentration. The NiCo grain size increases, and the coating thickness increases and then decreases with CoSiO4 concentration. A dense and uniform nickel-cobalt coating could be obtained after plating with 25 g/L CoSiO4 at 80 °C for 10 h. NiCo coated ZTAP ceramics reinforced high manganese steel matrix composites were fabricated using non-pressure casting infiltration. The results showed that NiCo improves the bonding property of composites causing a tighter and cleaner interface compared with severe defects of cracks, delaminations and holes on the interface of composites without NiCo coating. The effects of NiCo coating on tribological properties of the composites were clarified by the three-body abrasive wear. The superior interfacial bonding of composites assisted with NiCo coating exhibited excellent abrasive wear resistance, which increases by 230%.

The effect of multi-arc ion plating NiCr coating on interface characterization of ZrO2–Al2O3 ceramics reinforced iron-based composites

The ZrO2–Al2O3 (ZTA) ceramic particles reinforced iron matrix composite was a novel wear-resistance material because of their excellent toughness and hardness. However, the poor interfacial bonding property restricted the application of ZTAP/Fe composites in the harsh service condition. A continuous and uniform Ni80Cr20 coating on the ZTA ceramic surface was successfully prepared by multi-arc ion plating. The influence of NiCr coating on the interfacial character of ZTAP/Fe composites was investigated. The interface characteristics and phase constitutions of ZTAP/Fe composites were also analyzed by electron probe microanalysis (EPMA) and transmission electron microscopy (TEM). The results showed that the Ni80Cr20 coating can significantly improve the interfacial layer bonding of composites without visible defects. The diffusion of Ni and Cr and the formation of a continuous transition layer ensure the metallurgical bonding between ZTA ceramic and iron matrix. The composite N1 acquired better wear resistance than that of composite N2 without Ni80Cr20 coating, and the relative wear resistance was 1.98 times at the 55 N applied load. The interface of composite N1 was closely bonded with a transition layer, which may prevent the ceramic particles peeling off from the iron matrix during the wear process.

Developing eco‐friendly ceramic composite separator with competitive electrochemical properties using water‐based polymer binder for lithium‐ion batteries

The ceramic composite separators used in lithium-ion batteries (LIBs) are conventionally fabricated using a polymeric binder dissolved in an organic solvent, which can have adverse effects on the environment as well as the human body. Additionally, there are limited processes available for the fabrication of these separators owing to the requirement for carbon neutrality, which has attracted considerable attention worldwide to mitigate climate change. To address these issues, we propose an eco-friendly ceramic composite separator with outstanding adhesive strength and low interfacial resistance between the polyethylene (PE) separator and the aqueous polymeric binder with ceramic particles. To fabricate the proposed separator, the hydrophobic surface of the PE separator is preferentially modified into the hydrophilic surface by benzoyl peroxide (BPO) treatment. Following this, the water-soluble binder, that is, polyacrylic acid (PAA), with Al2O3 ceramic particles is coated on the surface of the pre-treated PE separator. The resultant PE separator with the hydrophilic surface and the water-based polymeric coating layer strongly adhere because of the formation of hydrogen bonds between the PAA and functional groups on the BPO pre-treated PE surface; these results in superior adhesive strength, and it reduces the interfacial resistance related with lithium-ion mobility through the separator. Consequently, the LIB half-cell employing the proposed separator displays superior rate performance and outstanding capacity retention.