Y2O3 Particles Research Articles

Enhancement of the photocatalytic efficiency of ZnO utilizing luminescent Y2O3 particles

Abstract This study explored the superior photocatalytic performance of the nanoscale zinc oxide-yttrium oxide (ZnO-Y2O3) based composite over ZnO nanoparticles (NPs). We investigated this by following the photocatalytic degradation efficiency of methylene blue (MB). The sol–gel synthesized Y2O3 and ZnO NPs were characterized by x-ray diffraction (XRD) and scanning electron microscopy (SEM) techniques. The spectral behaviour and photocatalytic efficiency of the proposed composite were investigated by UV–vis spectrophotometry, steady-state and time-resolved photoluminescence (PL) measurements, respectively. The results indicated the successful formation of Y2O3 and ZnO nanoparticles with desirable structural properties. The photocatalytic degradation efficiency of the MB solution was evaluated for different concentrations of the counterparts of the ZnO-Y2O3 composite. In particular, the ZnO-5Y2O3-based composite showed superior photocatalytic activity after 150 min of UV irradiation, achieving 98.4% degradation of the MB solution compared to the 77% degradation achieved by pure ZnO. Although Y2O3 alone does not exhibit photocatalytic activity, its combination with ZnO significantly enhances the photocatalytic performance of ZnO. This improvement was attributed to the luminescence properties of Y2O3. By elucidating this unique mechanism, the performance of photocatalytic materials can be significantly enhanced. In our study, the improvement of the photodegradation rate constant (kapp) of ZnO from 0.009 min−1 to 0.0242 min−1 demonstrated the promising photocatalytic efficiency of the ZnO-5Y2O3 based composite, opening up exciting possibilities for further applications in environmental remediation and other fields.

Effect of rare earth yttrium and the deformation process on the thermal deformation behavior and microstructure of pure titanium for cathode rolls

This study explores the challenges associated with microstructural refinement and homogenization control for large titanium cathode rolls utilized in electrolytic copper foil production. An innovative deformation control strategy was developed by incorporating yttrium microalloying within the β→α dual-phase region to refine the hot-deformed microstructure of pure titanium. Gleeble thermal simulation tests were performed to assess the impact of rare earth Y, deformation temperatures (700–900 °C), and interpass cooling rates (5 °C/s, 25 °C/s, and 50 °C/s) on the hot deformation behavior and microstructural evolution of pure titanium. The results reveal that Y2O3 particles generated by the addition of rare earth Y enhance dynamic recrystallization through the particle-stimulated nucleation (PSN) mechanism, effectively pinning grain boundaries and impeding recrystallized grain growth. Increased interpass cooling rates lead to finer grains and higher stored energy. The mechanism for grain refinement during dual-phase deformation is described as follows: β-phase nonrecrystallization temperature deformation → rapid cooling control → α-phase recrystallization deformation control, energy storage, strain-induced dynamic phase transformation (SIDT, α→β), and dynamic recrystallization (DRX). Under experimental conditions of β-phase region deformation at 980 °C → inter-pass cooling rate of 50 °C/s → α-phase region deformation at 750 °C, the addition of rare earth yttrium achieved the most effective grain refinement, reducing the average grain size to 2.56 μm.

Laser powder bed fusion in-situ alloying of W-Y alloy: Microstructure, mechanical properties and cracking suppression

The microcracks caused by impurity oxygen are recognized as one of the main challenges in additive manufacturing of tungsten. In this study, yttrium was incorporated into the tungsten matrix to suppress crack formation, and W-Y alloys with minimal cracks were successfully obtained by laser powder bed fusion (LPBF). It is found that during the LPBF process, yttrium combines with impurity oxygen to generate intergranular and intragranular precipitated particles in situ, which effectively suppress cracking behavior due to impurity oxygen. Furthermore, these intracrystalline nanoprecipitate are cubic Y2O3 particles that have formed a semi-coherent interface with the tungsten matrix. These dispersed particles significantly improved the mechanical properties of W-Y alloy. The results offer a corresponding strategy for crack suppression of tungsten alloys in laser additive manufacturing processes, and would provide a benificial additive manufacturing strategy to other refractory alloys.

Effect of Er2O3 and Y2O3 on microstructure and mechanical properties of Ti2AlNb alloy

Rare earth oxides can significantly refine the microstructure of the cast alloys and improve their mechanical properties. In this study, Er2O3 and Y2O3 particles were chosen to add into the Ti2AlNb-based alloy with vacuum non-consumable arc melting method. For the Er2O3 particles, it has obvious dissolution and re-precipitation characteristics during melting. While for the Y2O3 particles, they are more stable, and aggregated and grew up during melting. These two kinds of Er2O3 or Y2O3 both have obvious refinement effects on the B2 grains due to their heterogeneous nucleation. Specially, adding Er2O3 particles can promote the decomposition of the B2 and α2 phases and the increases of the O-phase content. But adding the Y2O3 particles can inhibits the B2 decomposition and just only promotes the α2 decomposition into the O-phase. Additionally, the TAC-Er2O3 ingot shows the worst mechanical properties at room-temperature due to its large size and grain boundary segregation of the Er2O3 reinforcements. Conversely, the TAC-Y2O3 alloy exhibits excellent strength and ductility whatever at room- and high- temperatures owing to its fine grain strengthening and effective strengthening of the second precipitated Y2O3 phases.

Impact of nano-Y2O3 on the physical, microstructure, and mechanical characteristics of Cu composite fabricated via powder metallurgy

This investigation focused on optimizing the adhesion of Y2O3 nanoparticles for uniform distribution within a copper matrix. Five samples were prepared with varying Y2O3 content (0%, 2.5%, 5%, 7.5%, and 10% by weight). To enhance bonding, a 5% nano silver coating was applied to the Y2O3 particles. The electroless deposition of copper nanoparticles onto the Y2O3 surface ensured even distribution within the matrix. The composite powders were then compressed at 700MPa and sintered at 950 °C for 140minutes. Density verification and microstructural analysis using scanning electron microscopy revealed a uniform distribution. Increasing the Y2O3 content gradually improved hardness, while wear rate measurements using a pin-on-disc method indicated a decrease with higher Y2O3 ratios. Additionally, electrical and thermal conductivity, along with the coefficient of thermal expansion, showed reductions with increasing Y2O3 content. This comprehensive approach provided valuable insights into the structural, mechanical, and conductive properties of the synthesized materials.

Microstructure evolution and degradation mechanisms of amorphous FeCrAlMoSiY coated Zr in 1200 °C steam

Herein, structural evolution and degradation mechanisms of the amorphous FeCrAlMoSiY coating during oxidation up to 16 h in 1200 °C steam was studied, using scanning electron microscopy, transmission electron microscopy, x-ray diffractometer, and Raman spectroscopy. The results revealed that no significant oxidation of the Zr substrate occurred within 12 h, which was attributed to the retarded atomic diffusion processes. These processes were achieved through the Al outward diffusion and formation of α-Al2O3 scale, along with the formation of an in-situ Zr2Si-rich diffusion barrier at the coating-substrate interface and the Y2O3 particles segregated at grain boundaries within the coating. Degradation of the coating was primarily due to the destruction of the α-Al2O3 scale by cracks caused by internal oxidation and voids accumulation. These results have implications for understanding the degradation mechanisms and achieving long-term stable protection of the coatings for Zr-based nuclear fuel claddings.

Nano Y2O3 particle enhanced IN718 nickel-based superalloy fabricated by laser powder bed fusion

In this study, 1 wt% Y2O3 nanoparticles were added into the IN718 superalloy fabricated by laser powder bed fusion (L-PBF). The results indicated a significant grain size refinement along the building direction and a substantial improvement in <100> texture. Room temperature tensile studies revealed that the addition of Y2O3 enhanced yield strength, ultimate tensile strength, and fracture elongation.

Synergistic effect of YAG particulate reinforcement on microstructural and thermo-mechanical properties of pressureless sintered MgAl2O4 spinel ceramic composites

Yttrium aluminum garnet (YAG) powders, synthesized through a partial wet chemical process, exhibit controlled morphology, high phase purity, and uniform homogeneity etc. This process involves the precipitation of aluminum ions onto Y2O3 particles. The transformation process of the Al-compound/Y2O3 precursor structure leads to the direct crystallization of pure YAG at 900 °C, passing through an intermediate stage where hexagonal YAH phase forms. A comprehensive study was conducted on the impact of preformed YAG as a reinforcing phase on the densification, mechanical, and thermo-mechanical properties of MgAl2O4-YAG composite, sintered under pressureless sintering in temperature range of 1500 °C–1600 °C. The inclusion of YAG particulate up to 5.0 wt% significantly enhances the densification, hardness, fracture toughness, flexural strength and high-temperature mechanical behavior of magnesium aluminate spinel (MAS) ceramics, however, increasing the YAG content beyond 5.0 wt% causes a reduction in these properties. The optimized addition of YAG particulate contributes to reducing the average grain size and refining the microstructure of the spinel ceramic matrix.

Synergistic effect of NiCr-Cr3C2 + Y2O3 to enhanced performance of Ti-based composite fabricated by laser cladding

The surface modification technology, which is of great significance in aerospace, energy, and other fields, is based on reinforcement. In this study, a titanium-based composite material system, formed using laser cladding and based on NiCr-Cr3C2 + Y2O3 dual additives, was investigated. TiC reinforcement particles were generated in situ through the reaction between NiCr-Cr3C2 and Ti6Al4V during the cladding process. Additionally, Ni and Cr elements provided solid solution-strengthening effects to the matrix. Meanwhile, Y2O3 particles were introduced ex-situ, effectively eliminating defects in the coating and inhibiting the dendritic growth of TiC particles. This process enhanced the dispersion-strengthening effect of TiC. The titanium-based composite material, incorporating NiCr-Cr3C2 + Y2O3, exhibited excellent tribological performance, displaying a wear rate of approximately 4.22 × 10−4 mm3·N−1·m−1.

In situ tailoring of precipitation behavior and improving mechanical properties of (Ti2AlC+Y2O3) reinforced TiAl alloy produced by directed energy deposition

A (Ti2AlC + Y2O3) synergistically reinforced Ti–48Al–2Cr–2Nb alloy was prepared by directed energy deposition with in situ tailoring of precipitate formation by induction preheating and thermal cycle. The influence of C and Y2O3 coaddition on the microstructure and high-temperature compressive properties was systematically investigated. The results indicated that Ti2AlC was formed by adding elemental C, and the Ti2AlC phase was mainly distributed in two forms: long rod-shaped Ti2AlC with a micron scale that distributed uniformly in the matrix, and lenticular Ti2AlC particles with nanometer size that distributed along the (α2/γ) lamellar interface. The Y2O3 particles were randomly distributed in the matrix. Columnar grains in vertical cross section along the building direction were completely eliminated by adding C and Y2O3. The high temperature compressive strength increased from 597 MPa to 758 MPa at 850 °C by adding C and Y2O3. Finally, the precipitation mechanism of nano-Ti2AlC was discussed in detail. This work provided a valuable reference for the preparation of high-performance TiAl alloys by in situ tailoring of the precipitates during the DED process.

Effect of dopant solubility and excess doping on the superconducting properties of doped Nb3Sn prepared by field assisted sintering technique

The present work is focused on understanding the role of Ruthenium (Ru) and Yttrium (Y) on the superconducting properties of the A15 Nb3Sn intermetallic compound. Ru and Y shows different solubility limit within the Nb3Sn matrix. Ru and Y-doped Nb3Sn superconducting alloys were prepared through mechanical alloying (MA) route followed by sintering using Field Assisted Sintering Technique (FAST). Analysis by X-ray diffraction demonstrates a significant decrement in crystallite size up to 0.5 wt% for the Ru-doped Nb3Sn followed by a significant increment when doping level reaches 1 wt% Ru. This could be the combined effect of structural disorderliness and Ru dissolution within the Nb3Sn matrix. While a significant increase in the crystallite size is observed for 0.5 wt% Y-doped Nb3Sn and no further change up to 1 wt% Y. This change could be a result of limited solubility of Y within the Nb3Sn matrix. Meanwhile, excessive Y plays an important role in the formation of additional flux pinning centers. The critical current density (Jc) shows a significant increase for all the Y-doped Nb3Sn alloys by a factor of 29 % due to the formation of Y2O3 from the residual Y, which is assumed to serve as additional flux pinning center. The Y2O3 particles was also considered as a possible cause of pinning down of grain boundaries in addition to NbO leading to grain refinement through Zener pinning. Ru-doped Nb3Sn alloys also exhibit an increase in Jc compared to pristine Nb3Sn, but only in concentrations up to 0.5 wt% Ru. At higher applied field, even 1 wt% Ru shows slight increase in Jc than pristine Nb3Sn. Y-doped samples showed superior functional properties.

Enhancing strength and ductility of Nb alloy via Y addition by vacuum electromagnetic levitation melting under oxygen carrier route

Niobium (Nb) is considered as candidate material for heat pipe in space nuclear reactors due to high melting point, low density, excellent compatibility with alkali liquid metals, irradiation resistance, workability and welding performance, but low strength restricts it's engineering application. In this work, yttrium (Y) was introduced into Nb matrix to achieve solution strengthening from Y atoms and dispersion strengthening from yttrium oxides. The latter one was realized by oxygen carrier route and vacuum electromagnetic levitation melting technique. Finally, one Nb521 (Nb-5.0 wt%W-1.7 wt%Mo-1.0 wt%Zr-0.07 wt%C) and four kinds of Nb521-xY (x = 0.1, 0.2 0.3 and 0.4 wt%) alloys were prepared. TEM characterization indicated that 80 nm Y2O3 particles were formed in Nb521-0.1Y, which exhibited the highest yield strength of 673 MPa, ultimate tensile strength of 740 MPa as well as larger elongation of 12.8%. Moreover, the solution strengthening of Y atoms and Orowan strengthening of yttrium oxides were evaluated quantitatively.

Enhanced ductility of PM Ti-Nb-Ta alloys via reducing solution oxygen by YH2 addition

To reduce the solution oxygen content in the matrix and enhance the ductility of Ti alloys prepared by powder metallurgy, YH2 was added as an additive to the Ti-Nb-Ta alloy in this work. By adding 1.5 wt%YH2, the compressive ductility increased 49 %, when the compression yield strength decreased slightly at room temperature, but the compression yield strength increased 41 % at 800°C compared with Ti-Nb-Ta without YH2 addition. With increase of YH2 content, the solution oxygen content in both α and β phases decreased significantly, while the proportion of ductile β phase increased. Addition of YH2 led to in situ formation of Y2O3 particles, reducing the solution oxygen content and changing the distribution state of oxygen. It is revealed that under a same deformation degree at 800°C, the dislocation density in the (Ti-5 Nb-15 Ta)-1.5 Y alloy sample is much higher than in the Ti-5 Nb-15 Ta alloy, which is attributed to a strong hindering effect of Y2O3 particles on dislocation movement. Thus, the strength of (Ti-5 Nb-15 Ta)-1.5 Y alloy was enhanced under high temperature. This study provided a new method for enhancing room temperature ductility and high-temperature strength of powder metallurgy Ti alloys.

Simultaneous enhancement of elevated temperature strength and ductility in additive-manufactured nickel-based superalloy via doping Y2O3 nanoparticles

In this work, we coated a layer of Y2O3 particles in Hastelloy X (HX) nickel-based superalloy powder by in situ chemical method and combined with laser powder bed fusion (LPBF) technology to develop a high-performance Y2O3-doping alloy, designated as Y-HX. The results show that the doping of Y2O3 particles prevents crack formation during the printing process and reduces solute segregation at cell and grain boundaries by increasing the viscosity of the molten pool. The doping of Y2O3 particles to the printed Y-HX alloy enhances grain boundary characteristics, transforming coarse sheet-like carbides into finely dispersed granular carbides at the boundaries during subsequent heat treatment. Additionally, doping with Y2O3 particles increases the recrystallization activation energy of the Y-HX alloy from 149.4 to 278.8 kJ mol–1. At 750 °C, the Y-HX alloy exhibits an ultimate tensile strength of 619 ± 2 MPa and an elongation of 52 % ± 2 %, along with an ultimate tensile strength of 325 ± 3 MPa and an elongation of 47 % ± 2 % at 900 °C. Our work provides a promising way to develop additive-manufactured superalloys with exceptional thermal stability and remarkable high-temperature mechanical properties.

Laser-powder bed fusion of Y2O3 nanoparticle modified CoCrNi matrix composites: Parameter optimization, microstructural evolution and strengthening mechanisms

Laser-powder bed fusion (L-PBF) delivers significant advantages in manufacturing metal matrix composites due to its micro-sized molten pool and fast cooling rate. In this work, a simple two-step process including the ultrasonic dispersion of ceramic particles and the volatilization of liquid medium by stirring was employed to synthesize Y2O3 nanoparticle modified CoCrNi matrix (Y2O3/CoCrNi) composite powders, which were subsequently processed for L-PBF to make samples. The effects of laser power (P) and hatch spacing (h) on the microstructures and mechanical properties of the L-PBF processed (L-PBFed) Y2O3/CoCrNi composites were investigated comparatively. The results confirm that the high P (350 W) and low h (60 μm) promoted the uniform dispersion of Y2O3 particles (∼50 nm) by altering the Marangoni flow, reducing the dynamic viscosity and increasing the remelting area. The L-PBFed Y2O3/CoCrNi composites under optimized condition exhibited a superior strength-ductility synergy, in which the yield strength, ultimate tensile strength and fractured strain were 647 MPa, 858 MPa and 42.2 %, respectively. It is demonstrated that a metallurgical defect-free hierarchical microstructure that involved dislocation-formed cellular structures, dispersion of Y2O3 particles and various crystallize defects (i.e. stacking faults, Lomer-Cottrell locks, and deformation twins) were responsible for the superb mechanical properties.

Assembly of Hollow Yttrium Oxide Spheres from Nano-Sized Yttrium Oxide for Advanced Passive Radiative Cooling Materials.

This study presents significant advancements in passive radiative cooling (PRC), achieved using assembled hollow yttrium oxide spherical particles (AHYOSPs). We developed PRC films with enhanced optical properties by synthesizing micro-sized hollow Y2O3 particles and integrating them into a polydimethylsiloxane (PDMS) matrix. The findings revealed that AHYOSPs achieved a remarkable solar reflectance of 73.72% and an emissivity of 91.75%, significantly outperforming nano-sized yttrium oxide (NYO) and baseline PDMS. Field tests demonstrated that the AHYOSPs maintained their lowest temperature during daylight, confirming their superior cooling efficiency. Additionally, theoretical calculations using MATLAB indicated that the cooling capacity of AHYOSPs reached 103.77 W/m2, representing a substantial improvement over NYO and robustly validating the proposed nanoparticle assembly strategy. These results highlight the potential of structurally controlled particles to revolutionize PRC technologies, thereby offering a path toward more energy-efficient and environmentally friendly cooling solutions.

Radiation Resistance of Optical Nanopowder Modified by Y2O3 Particles

Radiation Resistance of Optical Nanopowder Modified by Y2O3 Particles

A unique microstructure and its formation mechanism induced by laser cladding of Ti6Al4V alloy produced by laser powder bed fusion

A nickel based gradient laser cladding layer was successfully prepared on Ti6Al4V alloy produced by laser powder bed fusion (L-PBF). The nickel-enriched area of middle layer (NEAm) in the cladding layer had a unique structure. NEAm was composed of many large strip-like Ti2Ni grains. The sub-grain inside a single Ti2Ni grain presented a fine dendrite structure (these small dendrite units belong to the same grain, which was different from the traditional dendrite structure, so it was called "pseudo-dendrite"), the interdendrite was composed of amorphous phase or alternating β-Ti, Ti5Si3 nano-grains or mixtures of amorphous phase and the alternating structure. There were many massive TiNi and dispersed Y2O3, TiC and other fine second phase particles in the dendrite stem. Some of the Si-rich amorphous phase in the interdendrite transformed into alternating β-Ti and Ti5Si3 nano-grains. Thermodynamic calculation showed that the Gibbs free energies of amorphous phase in the top layer and NEAm were −13.353 and −33.619 kJ/mol, respectively. The glass-forming ability (GFA) values γABC* of the top layer and NEAm were 1.813 and 3.067, respectively. Obviously, the amorphous phase formation was easier in the NEAm than in the top layer, which explains the reason that although the cooling rate in the NEAm is slower than that in the top layer, the amorphous phase is only generated in the NEAm. The two-dimensional mismatch between of Y2O3 and Ti2Ni reached 15.43%, which was larger than the limit value of heterogeneous nucleation (12%), so Y2O3 in the NEAm did not play a role in heterogeneous nucleation. An unreported metastable phase was identified in a grain of Y2O3 in the NEAm. Since this phase was sensitive to electron irradiation, extremely limited photo-information was acquired. Accordingly, the Bravais lattice of the metastable phase was reconstructed; its most likely structure was simple cubic. Its lattice constant was anew phase = 3aorigin Y2O3 = 1.8369 nm, α = β = γ = 90°. Its orientational relationship with the parent-phase Y2O3 was ｛12̅1｝origin Y2O3∥｛110｝new phase，<1̅01>origin Y2O3∥<1̅10>new phase. The large increase of the phase interface, the pinning effect of the second phase, and the formation of amorphous phase significantly increased the hardness(up to 1100HV).

Microstructure and properties of oxide-reinforced FeCrAl matrix alloy manufactured by selective laser melting

In this work, nano-Y2O3 dispersed FeCrAl powders (NYD-Fe) were used to produce oxide dispersion strengthened (ODS) alloy by selective laser melting (SLM), and their microstructures and properties were investigated in detail by the kinds of characterization techniques. The results indicate that the Y2O3 particles adhered to the surface of FeCrAl powder absorb more laser, thus increasing the laser energy demand. High quality ODS deposits can be obtained at 600 mm/s and 180 W parameters. The ODS samples deposited by SLM exhibit coarse columnar grains with [001] texture. The Ti-rich nanoparticles and core-shell structured nanoparticles (Y- and O-rich core surrounded by a Ti-rich shell) are observed in ODS alloys. The precipitation formation of core-shell structured nanoparticles involves ball milling amorphization and dissolution reprecipitation. The ODS-180 alloy exhibits a higher ductility compared to FeCrAl-180 alloy, which is caused by the cellular structure with high density dislocations and the nano-sized precipitates inhibit the dislocation motion. The wear rate of the ODS-180 alloy is 51% lower than that of FeCrAl-180 alloy, which is mainly ascribed to the hardness and interface oxide layer resulting from its specific microstructural features.

Reducing reflection of down-shifting solar cells through scattering by particles

The improvement of down-shifting solar cells through reducing the reflection in short wavelength range by scattering is investigated experimentally and theoretically. Such down-shifting solar cells are fabricated by doping Y2O3 particles into down-shifting ethylene vinyl acetate films with CaAlSiN3:Eu2+ phosphors. Experimental results show that the scattering of Y2O3 particles can reduce the reflection of the down-shifting solar cells in the wavelength below 450 nm. It can be attributed to two reasons. The first is that the backscattering in the short wavelength is weaker than that in the middle and long wavelength. The second is that the scattering by Y2O3 particles allows more light reach the phosphors and increases their absorption. This means that more photons with poor spectral responses can be converted into the photons with better spectral responses. This work provides a way to realize simultaneously strengthening the down-shifting effect and suppressing the phosphor-induced reflection and can be used to further improve the down-shifting solar cells.