Yttrium Oxide Particles Research Articles

RESEARCH OF INJECTION METHODS FOR Y2O3 NANOPARTICLES INTO NICKEL- FREE STAINLESS STEEL DURING INDUCTION VACUUM REMELTING

Investigation of the possibility of obtaining an oxide-dispersed strengthening steel alloy based on 5 different ways of fine-dispersed strengthening particles Y2O3 injection into the liquid phase of steel Fe-13Cr (wt. %) in a vacuum. For this purpose, were conducted 5 series of experiments with different conditions and regimes. 2 series of 5 melts were carried out to evaluate the possibility of mechanical injection of yttrium oxide in the melt with different entry conditions. 3 series of 5 melts were conducted to evaluate the possibility of oxidation of metallic yttrium in the melt with the formation of yttrium oxide particles. Either melt residence or residual pressure in the furnace chamber was varied in different series. The results of ingot analysis on XRF, ICP-AES, and EDS showed that significant amounts of yttrium oxide were not injected. The method with oxidation of metallic yttrium in the melt from the reduction ofspecially added iron oxide with a concentration of 0.0552 ppm showed the best result.

Modification of stability properties of yttrium(III) oxide particles by simultaneous adsorption of poly(acrylic acid) and poly(ethylene glycol) for possible applications in wastewater treatment

The adsorption, electrokinetic and stability properties of yttrium(III) oxide—Y2O3 in mixed solutions of macromolecular compounds were investigated. The interfacial behavior of poly(acrylic acid)-PAA and poly(ethylene glycol)—PEG in single and binary systems was examined in the pH range 3–10. The polymers used were characterized by different ionic nature—the PAA is an anionic polymer, whereas PEG belongs to the group of non-ionic polymers. Based on the results obtained, the most probable mechanisms for the binding of PAA and PEG macromolecules on the yttrium(III) oxide surface were proposed. In addition, the analysis of adsorption and electrokinetic data enabled explanation of the obtained changes in the stability of Y2O3 suspensions without and in the presence of PAA or/and PEG, as well as determination of the specific stabilization-destabilization mechanisms of the studied systems. It was shown that yttrium(III) oxide modification by mixed adsorption layers of both polymers with different ionic character changes considerably the surface and stability properties of the examined solid suspensions.Graphical

Effects of solid–liquid doping and spark plasma sintering on the microstructure and mechanical properties of Y2O3-doped copper matrix composites

High-strength and high-conductivity copper alloys have a wide range of applications, such as an important electrical contact material. In this work, Cu–Y2O3 composite material was prepared through solid–liquid doping, calcination reduction, and spark plasma sintering. The effect of different yttrium oxide content (1, 3, and 5 wt%) on the microstructure and mechanical properties of the composite was studied. Results showed that the surface of the calcined and reduced copper powder was uniformly covered with yttrium oxide particles. After spark plasma sintering, the relative density of the blocks almost reached 100%. With the increase in yttrium oxide content, the distribution of yttrium oxide transformed from dispersion to agglomeration, and the grain size gradually decreased. There is a good bond between the copper matrix and yttrium oxide, and the particle size of yttrium oxide particles is approximately 150 nm. In terms of mechanical properties, the Cu-3wt.% Y2O3 sample obtained the best comprehensive mechanical properties with strength of 290.1 MPa, hardness of 125.7 HV, and conductivity maintained at a high level of 95% International Annealed Copper Standard (hereinafter called IACS).

Experimental Investigation of Mechanical and Tribological Characteristics of Al 2024 Matrix Composite Reinforced by Yttrium Oxide Particles

Composite materials offer distinct and unique properties that are not naturally inherited in the individual materials that make them. One of the most attractive composites to manufacture is the aluminum alloy matrix composite, because it usually combines easiness of availability, light weight, strength, and other favorable properties. In the current work, Powder Metallurgy Method (PMM) is used to prepare Al2024 matrix composites reinforced with different mixing ratios of yttrium oxide (Y2O3) particles. The tests performed on the composites include physical, mechanical, and tribological, as well as microstructure analysis via optical microscope. The results show that the experimental density slightly decreases while the porosity increases when the reinforcement ratio increases within the selected range of 0 ~ 20 wt%. Besides this, the yield strength, tensile strength, and Vickers hardness increase up to a 10 wt% Y2O3 ratio, after which they decline. Moreover, the wear results show that the composite follows the same paradigm for strength and hardness. It is concluded that this composite is ideal for application when higher strength is required from aluminum composites, as well as lighter weight up to certain values of Y2O3 ratio.

Evaluation of microhardness and wear properties of Al 6063 composite reinforced with yttrium oxide using stir casting process

PurposeThis study aims to analyse the changes in mechanical and wear performance of aluminium alloy when yttrium oxide particles are incorporated. The microstructures are studied to analyse the change in the grain structures. Worn surfaces are observed via scanning electron microscope to study the wear mechanism in detail.Design/methodology/approachStir casting is used to incorporate varying composition of yttrium particles, having an average particle size of 25 micrometer, in aluminium alloy 6063 matrix. Wear testing is carried out by DUCOM manufactured high temperature rotatory tribometer, and an indentation test is used for analysing the microhardness of the fabricated samples.FindingsMicrohardness of the material is increased with the increasing content of particulate addition. With the increasing content of reinforcement, more refined grains are produced. The load is transferred from the matrix to more rigid yttrium oxide particles. These factors contributed to escalated microhardness of the reinforced samples. Particulate addition enhanced the wear performance of the material; this might be attributed to increased microhardness and formation of an oxide layer.Originality/valueAluminium composites are finding wide applications in various industries, and there is always a requirement of material with enhanced tribological properties. Yttrium oxide particles exhibit improved mechanical properties, and their interaction with the aluminium matrix has not been studied much in the past. So, in this work, yttrium oxide incorporated aluminium matrix is studied.

Effective joining between oxide dispersion strengthened tungsten-based material (ODS-W) and TZM alloy via spark plasma sintering technology

In this work, the effective connection between oxide dispersion strengthened tungsten-based material (ODS-W) and TZM alloy has been realized via spark plasma sintering technology. The appropriate processing parameters have been investigated, and the joints were analyzed through scanning electron microscopy, microhardness measurement, X-ray diffractometry, and TEM test. Results show that, at 1500 ​°C, the interface presented good metallurgical bonding and no obvious defects, the diffusion distance between ODS-W/TZM alloy is the longest, and the mutual diffusion distance from molybdenum to tungsten is 2.2 ​μm. When yttrium oxide particles exist in the joint, the diffusion distance between them increases. The hardness of the ODS-W/TZM alloy joint can reach approximately 411 HV. The tensile strength of the joints was as high as 485 ​MPa. Transmission electron microscope photos show that when yttrium oxide particles exist at the interface, the mutual diffusion distance between tungsten and molybdenum is approximately 400 ​nm.

Homogeneous Dispersion of Yttrium Oxide Particles in Nickel-Based Superalloy by High Pressure Homogenizing and Ball Milling Method

Homogeneous Dispersion of Yttrium Oxide Particles in Nickel-Based Superalloy by High Pressure Homogenizing and Ball Milling Method

Ab initio modelling of titanium impurities in α-Fe lattice

Reduced activation ferritic-martensitic (RAFM) as well as ferritic steels strengthened by yttrium oxide are considered as candidate materials for future fusion and advanced fission reactors. Addition of Ti during the manufacturing of the oxide dispersed strengthened (ODS) leads to the formation of yttrium titanium oxide particles, which size is smaller compared to yttrium oxide particles. This improves the mechanical properties and radiation resistance of the ODS steels. DFT calculations of Ti impurities have been performed to determine the factors contributing to the formation of the nanoparticles in α-Fe (bcc-Fe) based steels. The interaction energies between TiFe-OFe, TiFe-Ooct, TiFe-TiFe, TiFe-YFe, and TiFe-VFe have been calculated. The obtained results point to the noticeable interactions of the point defects up to the second nearest neighbours for the most of the defect combinations considered and could be used in following lattice kinetic Monte Carlo (LKMC) modelling of the ODS particle formation process in ODS steels.

Possibility of using yttrium oxide powder as a strengthening phase for centrifugal casting of corrosion-resistant steels

The authors have made an analysis of necessity to improve the composition of the existing structural materials for critical purposes in the direction of creating metal matrix materials, which combine a highly plastic metal base and refractory high-strength high-modulus fillers. For iron matrix alloys, dispersed yttrium oxide (Y2O3 ) particles are preferred because of their stability at pyrometallurgical process temperatures and inertness to alloy components. The technology of obtaining new materials by introducing dispersed particles into a liquid melt during casting using a centrifugal casting machine to obtain a hollow (pipe) billet is considered. The possibility of increasing the mechanical and operational properties of metal matrix materials in comparison with monomaterial is shown. The article describes results of the thermodynamic modeling of high-temperature processes occurring in the yttrium oxide - metal matrix (melt) system. Modeling was carried out using the FactSage software package. A composition corresponding to 12Cr18Ni10Ti steel was used as the modeling composition of the matrix material. The calculations were made according to the ratio of 1 g of yttrium oxide additive per 100 g of matrix metal melt. From the simulation results it is possible to conclude that the introduced dispersed yttrium oxide powder does not interact with the alloy components, does not dissociate, and does not undergo allotropic transformations. The expediency of conducting experiments on the production of centrifugal castings using yttrium oxide as a hardening phase with the aim of a possible increase in radiation resistance is shown. Directions are indicated for developing the most effective technology for creating metallic materials based on an iron matrix dispersed-hardened by yttrium oxide.

Effect of low-density polyethylene on the luminescent properties of thulium-doped yttrium oxide obtained by the polyol technique

In the present work polyethylene is used as a support of yttrium oxide particles doped with thulium atoms and its effect on the luminescent properties is studied. Thulium-doped yttrium oxide was prepared through the polyol method, different values of thulium are explored: 0, 0.5, 1, 1.5, 2.5 and 3.5 at%, as well as different calcinating temperatures: 400, 600, 800 and 1000 °C, are explored in order to determine the synthesis conditions needed for the maximum emission intensity, whose values were 1.5 at% of thulium and 1000 °C. The synthesized powder is dispersed in low-density polyethylene and dispersed as a thin film on glass substrates. The luminescent excitation and emission spectra showed important changes attributed to the influence of the -CH2– chain vibration; in addition, the presence of the polymer had an important influence on the emission decay time: while the powder showed a single emission process with a time of 9.293 μs, the film showed a two decay process with 1.156 μs and 4.086 μs, each.

Effect of cationic, anionic and non-ionic polymeric surfactants on the stability, photo-catalytic and antimicrobial activities of yttrium oxide nanofluids

This work describes the utilization of combining the properties of yttrium oxide as a photoactive metal oxide and the properties of different kinds of charged surfactants: cationic, anionic and non-ionic polymeric types. The surface charge of surfactants was found to have a great influence on the stabilization performance of yttrium oxide particles in aqueous surfactant media, known as nanofluids, as well as on their photocatalytic and antimicrobial activities. Ionic surfactants (cetyltrimethylammonium bromide (CTAB) as a cationic surfactant and sodium dodecyl sulfate (SDS) as an anionic one) reduce the particle aggregation while the non-ionic polymeric surfactant (Polysorbate 80, Polyoxyethylene (20) sorbitan monooleate or (x)-sorbitan mono-9-octadecenoate poly(oxy-1,2-ethanediyl) (Tween 80)) enhanced the particles aggregation and formed a polymeric layer on the aggregates surface. The prepared nanofluids morphological structure and stability were studied by means of TEM, DLS and Zeta potential measurements. The prepared nanofluid systems were found to have an enhanced photo-catalytic performance for the degradation of MG dye studied under both UV and visible light irradiations and an enhanced wide spectrum antimicrobial activity against Gram positive and Gram negative bacteria as well as fungal stains.

Characterization of Y2O3 particles reinforced AA6082 aluminum matrix composites produced using friction stir processing

The effect of Yttrium oxide (Y2O3) particles on the microstructure and mechanical behaviour of AA6082 alloy composite fabricated via Friction stir process (FSP) has been investigated. Structural analysis is carried out using x-ray diffraction (XRD) and microstructural analysis is carried out using Optical Microscopy (OM) and Scanning Electron Microscope (SEM). From the analysis it is inferred that the Y2O3 particles significantly affect the microstructure, hardness, tensile and wear properties of AA6082 alloy. The observed mechanical properties are interconnected with microstructure and fractography.

Effect of Yttrium Oxide Particles on the Mechanical Properties of Polymer Matrix Composite

Polymeric composite materials have emerged as one of the best composites used in modern and advanced applications due to the important and useful properties such as lightweight, excellent thermal and electrical insulation as well as relatively good resistance. In this paper, a composite material has been manufactured with polymer matrix which is reinforced with ceramic particles and the mechanical properties have been studied. Epoxy resin Quick mast 105 has been mixed with a hardener by a ratio 3:1, then reinforced with different volume fractions of Yttrium oxides Y2O3 (0, 1.5, 3, 4.5, 6%). The composites samples are manufactured with hand lay-up molding, then the mechanical properties such as hardness, compressive strength, flexural strength and the wear rates with different loads (5, 10, 15, 20) Newton are investigated. The results showed that both hardness and compressive strength were increased by increasing the content of the reinforcement as it increased by 62% and 12% respectively, in contrast to flexural strength which decreased by increasing the Y2O3 content by 45%, the wear results showed a decrease in the wear rate by increasing the Y2O3 content up to 3% and then the wear rate is proportional with the reinforcement content and 0% recorded the highest wear rate, on the other hand by increasing the load of the wear rate test, it was found that the wear rate increased at all the ratios of reinforcement.

Effect of Yttrium Oxide Particles on the Mechanical Properties of Polymer Matrix Composite

Polymeric composite materials have emerged as one of the best composites used in modern and advanced applications due to the important and useful properties such as lightweight, excellent thermal and electrical insulation as well as relatively good resistance. In this paper, a composite material has been manufactured with polymer matrix which is reinforced with ceramic particles and the mechanical properties have been studied. Epoxy resin Quick mast 105 has been mixed with a hardener by a ratio 3:1, then reinforced with different volume fractions of Yttrium oxides Y2O3 (0, 1.5, 3, 4.5, 6%). The composites samples are manufactured with hand lay-up molding, then the mechanical properties such as hardness, compressive strength, flexural strength and the wear rates with different loads (5, 10, 15, 20) Newton are investigated. The results showed that both hardness and compressive strength were increased by increasing the content of the reinforcement as it increased by 62% and 12% respectively, in contrast to flexural strength which decreased by increasing the Y2O3 content by 45%, the wear results showed a decrease in the wear rate by increasing the Y2O3 content up to 3% and then the wear rate is proportional with the reinforcement content and 0% recorded the highest wear rate, on the other hand by increasing the load of the wear rate test, it was found that the wear rate increased at all the ratios of reinforcement.

Facile meltPEGylation of flame-made luminescent Tb3+-doped yttrium oxide particles: hemocompatibility, cellular uptake and comparison to silica.

Flame aerosol technology is a versatile method for scalable synthesis of nanoparticles. Since particles are produced and collected in a dry state, dispersibility and further functionalization could pose hurdles to their biomedical use. We report on a one-pot, scalable and robust procedure for the PEGylation of flame-made yttria and silica nanoparticles. We demonstrate improved colloidal stability, attenuated activation of blood coagulation and decreased uptake into phagocytic cells, all of which pave the way for facilitated biomedical use of flame-made oxide nanoparticles.

Crystallization behavior of the Al86Ni8Y6 metallic glass forming alloy upon rapid cooling

In this study, the crystallization behavior of Al86Ni8Y6 upon rapid cooling from the equilibrium melt is investigated and the crystalline phases that compete with the glass formation are identified. Al86Ni8Y6 is one of the best glass formers in the ternary Al-Ni-Y system. Contrary to previous studies suggesting α-Al as the primary phase upon quenching, this study reveals that glass formation is strongly restricted by the formation of the primary precipitating ternary intermetallic compound Al23Ni6Y4. The nucleation of Al23Ni6Y4 appears to be triggered by yttrium oxide particles present in the melt acting as heterogeneous nucleation sites. Once the primary phase Al23Ni6Y4 has been formed, further crystallization of the Ni and Y depleted melt occurs as α-Al. The corresponding results are shown and discussed with respect to their effects on the glass formation.

Effect of the chemical composition and the structural and phases states of materials on hydrogen retention

The results of investigation of the effect of chemical composition and structural and phase states of reactor steels and vanadium alloys on their capture and retention of hydrogen introduced into the materials in various ways are presented. It is shown that, in the case of identical conditions of hydrogen introduction, the amount of hydrogen captured by austenitic steels is substantially higher than that captured by ferritic/ martensitic steels. At the same time, the EP450 ODS ferritic/martensitic steel dispersion-strengthened with nanosized yttrium oxide particles retains a substantially higher amount of hydrogen as compared to that retained in the EP450 matrix steel. The alloying of vanadium with tungsten, zirconium, and titanium leads to an increase in the amount of retained hydrogen. The effect of titanium content on hydrogen retention is found to be nonmonotonic; the phenomenon is explained from a physical view point.

Fabrication of Fe-base superalloy powders with yttrium oxide dispersion by mechanical alloying and chemical route

The ferritic alloy powders with homogeneous dispersion of yttrium oxide nanoparticles were fabricated by polymeric additive solution route. The Fe-Cr-Al-Ti alloy powders were prepared by high energy ball milling, and yttrium oxide particles on the alloyed powder surfaces were formed by calcination of a precursor solution containing yttrium nitrate and polyvinyl alcohol. In the powder mixture calcined at 600°C, amorphous yttrium nanoparticles were formed, whereas homogeneous ferric ODS alloy powders with dispersion of Y4Al2O9 crystal nanoparticles were observed by the chelating reaction between yttrium cations and PVA in the powder mixture after calcination at 800°C. This study contributes a promising approach to fabricate ferritic ODS alloys with homogeneous dispersion of oxide nanoparticles.

Size-dependent cytotoxicity of yttrium oxide nanoparticles on primary osteoblasts in vitro

Yttrium oxide nanoparticles are an excellent host material for the rare earth metals and have high luminescence efficiency providing a potential application in photodynamic therapy and biological imaging. In this study, the effects of yttrium oxide nanoparticles with four different sizes were investigated using primary osteoblasts in vitro. The results demonstrated that the cytotoxicity generated by yttrium oxide nanoparticles depended on the particle size, and smaller particles possessed higher toxicological effects. For the purpose to elucidate the relationship between reactive oxygen species generation and cell damage, cytomembrane integrity, intracellular reactive oxygen species level, mitochondrial membrane potential, cell apoptosis rate, and activity of caspase-3 in cells were then measured. Increased reactive oxygen species level was also observed in a size-dependent way. Thus, our data demonstrated that exposure to yttrium oxide nanoparticles resulted in a size-dependent cytotoxicity in cultured primary osteoblasts, and reactive oxygen species generation should be one possible damage pathway for the toxicological effects produced by yttrium oxide particles. The results may provide useful information for more rational applications of yttrium oxide nanoparticles in the future.

Investigation of microstructure changes in ODS-EUROFER after hydrogen loading

The effect of hydrogen on the microstructure of mechanically tested ODS-EUROFER steel was investigated by means of transmission electron microscopy, thermal desorption spectroscopy, and atomistic simulations. The presence of yttrium oxide particles notably increases hydrogen uptake in ODS-EUROFER steel as compared to ODS-free EUROFER 97. Under tensile loading, hydrogen accumulation promotes the loss of cohesion at the oxide particle interfaces. First-principles molecular dynamics simulations indicate that hydrogen can be trapped at nanoparticle/matrix interface, creating OH-groups. The accumulation of hydrogen atoms at the oxide particle surface can be the reason for the observed hydrogen-induced oxide/matrix interface weakening and de-cohesion under the action of external tensile stress.