Increasing Y2O3 Content Research Articles

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 700 MPa and sintered at 950 °C for 140 minutes. 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.

Enhancing mechanical properties of 2024-Aluminium Alloy Matrix Composite strengthened by Y2O3 ceramic particles

The development of high-strength, low-weight composite materials has been a high-priority demand in the structural, aerospace, automotive, renewable energy, and sports equipment sectors. Micro-particle size Yttrium oxide (Y2O3) has been utilized to enhance the microstructure and mechanical characteristics of the 2024-Al alloy. The stir-casting technique is employed to prepare 2024-Al alloy and aluminum matrix composites (AMCs) with different Y2O3 weight fractions (1 %, 2 %, and 3 %). Scanning electron microscope ESM with EDS analysis and optical microscope imaging have been used to assess the development in the microstructure of AMCs. Furthermore, optical microscope images have been analyzed by using image processing software, ImageJ to evaluate development in microstructure grain size. Vickers' micro-hardness, tensile strength, elongation, and wear-resistant tests were conducted to assess the mechanical properties of AMCs. AMC image analysis results demonstrated a significant reduction in microstructure grain size. The highest reduction in grain size was recorded when adding 2 wt. % of Y2O3, which was approximately 22.5 % smaller than that of the plain alloy. Other mechanical test results demonstrated an increase in the hardness and tensile strength of AMCs compared with the plain alloy by approximately 58 % and 116 %, respectively, upon the addition of 2 wt. % of Y2O3, also tensile test shows increasing of AMCs elongation at failure point with increasing Y2O3 content, 132 % upon adding 3 wt. %. Finally, wear tests show a decrease in the AMC wear rate with an increasing Y2O3 weight fraction compared to the plain alloy.

Characterization of Al/B4C–Y2O3 hybrid composites produced by vacuum hot pressing combined with Al2O3–Y2O3 interaction

In this study, the Al/B4C/Y2O3 hybrid composites were produced by Al2O3 and Y2O3 interaction via hot pressing. Moreover, the influence of Y2O3 on the properties of Al/B4C 10 wt% was investigated. The hot pressing was performed at 600 °C with pre-oxidized aluminium powder to produce the composites. The microstructure analyses revealed that Al/B4C/Y2O3 hybrid composite production was achieved by Al2O3 and Y2O3 interaction, and the Y4Al2O9 (YAM) phase was obtained in the Al–B4C/Y2O35 % sample. The Y2O3 addition increased the porosity content of the Al/B4C structure. However, wear rate and corrosion resistance of the Al/B4C were enhanced owing to the presence of Y2O3. The wear rate of Al/B4C was reduced from 26.55·10−7 cm3/Nm to 5.68·10−7 cm3/Nm at 15 N test load. The increasing Y2O3 content and the formation of the Y4Al2O9 decreased the corrosion rate of the Al/B4C fom 0.0179 mm/year to 0.0051 mm/year. Also, corrosion damage was shifted from the matrix to the reinforcement zone in Al–B4C/Y2O35 % sample, and the aluminium was protected owing to the presence of Y2O3 and Y4Al2O9.

Effect of Y2O3 content on microstructure and corrosion behavior of ZrO2 coatings in liquid Lead-Bismuth eutectic

The microstructure and corrosion resistance of Y2O3 doped ZrO2 coatings are investigated in static liquid lead-bismuth eutectic (LBE) at 550–650 °C for 5000 h. The addition of Y2O3 facilitates the crystallization of the ZrO2 coating, and the coating is composed of c-ZrO2. The hardness and elastic modulus of the coating increase with increasing Y2O3 content. The ZrO2 coatings doped with 5 and 6 mol.% Y2O3 undergo dissolution corrosion due to stress-induced cracks and spallation during the corrosion process at 550 °C. In contrast, ZrO2 coating doped with the 4 mol.% Y2O3 maintains a dense and intact structure even after 5000 h of corrosion at 550–650 °C. Therefore, the results show that the ZrO2 coating doped with 4 mol.% Y2O3 has good corrosion resistance and can be used as a potential fuel cladding protective coating for lead-cooled faster reactor (LFR) reactor applications.

Effect of nano-Y2O3 on the microstructure and mechanical properties of Cu-10W composites prepared by spark plasma sintering

Cu-W composites with high strengths and high conductivities have diverse applications. At present, studies on Cu-W composites with low W content (<50 wt%) are scarce. In this study, Cu-10 wt% W (hereinafter referred to as Cu-10W) composites reinforced by nano-Y2O3 particles with various Y2O3 contents were prepared via ball milling and spark plasma sintering (SPS). The effects of different Y2O3 contents (1, 2 and 3 wt%) on the microstructure and mechanical properties of the composites were studied. The results show that the Y2O3 and W particles were uniformly distributed in the Cu matrix. With increasing Y2O3 content, the distribution of Y2O3 changed from dispersion to agglomeration, and the grain size gradually decreased. The hardness and compressive yield strength increased gradually. In addition, the electrical conductivity was maintained above 81.76 %IACS (as stipulated by the International Annealed Copper Standard). For the Y2O3 content of 2 wt%, the density and relative density of the composites reach the maximum values of 9.18 g/cm3 and 98.65%, respectively. At this time, the tensile strength reaches 353.8 MPa. The combination between the matrix and Y2O3 was good, and the composites showed the best comprehensive performance.

Impact of Y2O3 on the structural, linear and nonlinear optical parameters of Na2O-Fe2O3-B2O3 glass

In this work, we investigated the effect of Y2O3 additives on the microstructure and some optical features of Fe2O3 and Na2O-containing borate glasses. FTIR spectra were studied to explore the microstructure and functional units such as BO3, BO4 and nonbridging oxygen (NBO) content. The areas related to BO3 and BO4 bands were calculated from the deconvolution results. Moreover, the BO4/(BO4 +BO3) ratio, called the N4 parameter, was employed to study the microstructure changes induced by Y2O3/Na2O substitution. Moreover, we found the N4 parameter decreased with rising Y2O3 from 0 to 5 mol.%. In contrast, the area and height of the NBO-related band increased with the rise in Y2O3 from 0 to 5 mol.%. The latter two results reflect decreasing the BO4 content but increasing NBO contents in our glasses with more Y2O3 additives. This reduction in BO4 can be attributed to the higher field strength of Y3+ than the field strength of Na1+. Furthermore, the metallization criterion (MC) showed a very slight decrease from 0.403 to 0.401 with additional additives of Y2O3. Based on the obtained values of MC, the current Y2O3 containing glass samples present high nonlinear features. Further, nonlinear optical parameters showed increasing trends with increasing Y2O3 content.

Effect of Y2O3 content on the microstructural characteristics and the mechanical and thermal properties of Yb-doped SiAlON ceramics

SiAlON ceramics are primarily employed in ceramic cutting tools, which exploit their stable physical properties in high-temperature cutting environments due to their excellent mechanical properties. Here, Yb/Y-co-doped SiAlON ceramics are prepared by adding Yb and Y rare-earth (RE) ions in the RExSi12-(m+n)Alm+nOnN16-n (m = 0.4, n = 1.0) composition. Yb2O3, the RE oxide, is the main sintering additive. For REx composition design with (Yb1-y + Yy)x, Yb2O3 is replaced by Y2O3 (y = 0.00, 0.25, 0.50, 0.75, 1.00). While Yb2O3 has excellent high-temperature stability, it is limited by its microstructural characteristics, that is, the β-SiAlON morphology and limited fracture toughness due to the small cation sizes. Thus, the changes in the above properties are investigated for various Y2O3 additive contents substituting for Yb2O3. The average grain width decreases, and the equiaxed β-SiAlON grains are elongated with increasing Y2O3 content. Regarding the mechanical properties, the hardness and fracture toughness are evaluated using the indentation fracture method. The hardness decreases with increasing Y2O3 content; however, the fracture toughness exhibits a significant increase (∼53.6%) from 4.6 to 7.0 MPa⋅m1/2. Regarding crack propagation, intergranular fracture is mainly observed in the Yb/Y-co-doped SiAlON ceramics, whereas transgranular fracture is primarily observed in the Yb-single-doped SiAlON ceramic. Y2O3 substitution increases the α/β-SiAlON phase ratio, and the grain boundary phase exhibits increasing vitrification with increasing Y2O3 content. Moreover, the thermal properties of the Yb/Y-co-doped compositions are analyzed and discussed regarding intrinsic properties such as phonon scattering. The microstructural characteristics and improved fracture toughness derived from the Yb/Y-co-doped system designed in this study suggest considerable potential for the future composition design of ceramic cutting tools.

The effects of in-situ formed phases on the microstructure, mechanical properties and electrical conductivity of spark plasma sintered B4C containing Y2O3

B4Cs without additive and 5, 10 and 15 wt % Y2O3 containing B4Cs were produced by using spark plasma sintering (SPS) technique at different temperatures such as 1820, 1930 and 2030 °C and the effects of in-situ formed phases on the mechanical properties and electrical conductivity of B4C were investigated. Microstructural investigations showed that the YB4 phase was formed at 1820 °C and the YB6 phase at 1930 °C. The hardness values of B4C-YB4 composites were higher than the value of B4C sintered at 1820 °C while lower than that of sintered at 2030 °C. The fracture toughness steadily increased with increasing Y2O3 content. The electrical conductivity of B4C sintered at 2030 °C increased by ∼ 40 % with the contribution of in-situ formed YB4 phase. Compared to B4C-YB4, B4C-YB6’s hardness was higher, while its fracture toughness and electrical conductivity were lower.

Mechanical properties, translucency, and low temperature degradation (LTD) of yttria (3–6 mol%) stabilized zirconia

The mechanical properties (hardness and biaxial flexural strength), optical properties (translucency and gloss), and low temperature degradation (LTD) of 3–6 mol% yttria stabilized zirconia have been investigated. The specimens were prepared by conventional solid-state sintering at 1400 °C. The mechanical and optical properties were evaluated for sintered and polished specimens. X-ray diffractometer (XRD) and scanning electron microscope (SEM) were used, respectively, for structural and microstructural investigation. LTD was determined by XRD analysis of the samples aged in a hydrothermal autoclave at 134 °C for 5–108 h. The mechanical and optical properties are found to be microstructure sensitive. The LTD, due to tetragonal to monoclinic phase transformation, decreases with increasing Y2O3 content. The mechanical strength, translucency, and LTD are the lowest for 6 mol% Y2O3 stabilized zirconia.

Microstructure and thermal conductivity of gas-pressure-sintered Si3N4 ceramic: the effects of Y2O3 additive content

Si3N4 ceramics were sintered at 1900 °C under a nitrogen pressure of 1 MPa using Y2O3-MgO additives. The effects of Y2O3 content (0.5-4 mol%) on microstructure and thermal conductivity were systematically investigated. The increasing Y2O3 content led to increases in amount and viscosity of liquid phase during sintering, which induced a “bimodal to normal” transition in distribution of grain size, decreased Si3N4/Si3N4 contiguity and enhanced devitrification degree of intergranular phase in sintered bulks. Moreover, the decreasing Y2O3 content was found to improve the elimination efficiency of SiO2 impurity during sintering, resulting in lower lattice oxygen content in densified specimens. The microstructure had a strong effect on thermal conductivity. The samples sintered for 3 h gained an increase of thermal conductivity from 65 to 73 W·m-1 K-1 with increasing Y2O3 content, while the samples sintered for 12 h obtained a substantial increase of thermal conductivity from 87 to 132 W·m-1 K-1 with decreasing Y2O3 content.

Characteristics and local structure of hafnia-silicate-zirconate ceramic nanomixtures.

Zirconate systems having the composition 3HfO2·15SiO2·xY2O3·(82 - x)ZrO2, where x = 2, 7 and 12 mol% Y2O3, were synthesized by a sol-gel method. The analysis of X-ray diffraction data showed the presence of the t-ZrO2, m-ZrO2, m-HfO2, Y2SiO5 and Y2Si2O7 crystalline phases in a ceramic nanomixture. Spectroscopic data show that the increase of the Y2O3 content of samples determines the increase of the t-ZrO2, m-HfO2 and silicate crystalline phases. Gap energy values decrease almost linearly with increasing Y2O3 content of samples. A detailed study of XANES data does not show a significant difference with increasing Y2O3 content of the samples suggesting an appreciable stability of the hafnium ions +4 oxidation state and their microvicinity. EXAFS results show that the local structure around the Hf cation is similar to that from the monoclinic crystalline HfO2 where the Hf-O coordination number tends to 7. The bond lengths of Hf-O shells show small deviations from ∼2.12 Å and the Hf-metal paths become more structured by increasing the Y2O3 content of thesamples.

Mesoscale understanding of ionic conduction in yttria stabilized zirconia: the nanoscale percolation network and its effect on O2− ion movement**Invited paper for focus issue in Modeling and Simulation in Materials Science and Engineering (MSMSE).

Yttria-stabilized zirconia (YSZ) is widely used as a fast oxygen ion conductor in solid oxide fuel cells. Over the years several studies have probed the effect of different cation arrangements on the O2− ion hopping behavior at the atomistic scale. However, an analytical model that can predict the macroscopic ionic conductivity using both the atomic scale hopping behavior as well as the spatial arrangement of cations at the mesoscopic length scale is lacking. A novel mesoscale model is constructed as a step towards addressing this gap. First, using a kinetic Monte Carlo (KMC) model for YSZ we find evidence of a fast ion conducting percolation network being present. The tortuous network, which consists of connected regions spanning the material structure, mainly contributes to the ionic conduction as O2− ion movement in other regions is relatively slow. The topology, composition and O2− ion movement in the network are analyzed. Next, the shortest path lengths in the network are identified with the help of the Dijsktra algorithm. Finally, a diffusion model is developed that relates the atomic scale hopping rates and shortest path lengths (a mesoscale feature) to the macroscale ionic conductivity. Estimates for ionic conductivity from the diffusion model are in excellent agreement with the KMC model. Changes within the percolation network with increasing Y2O3 content can describe the maximum observed in ionic conductivity.

Influence of Y2O3 Addition on Crystallization, Thermal, Mechanical, and Electrical Properties of BaO-Al2O3-B2O3-SiO2 Glass–Ceramic for Ceramic Ball Grid Array Package

Y2O3 addition has a significant influence on the crystallization, thermal, mechanical, and electrical properties of BaO-Al2O3 -B2O3 -SiO2 (BABS) glass–ceramics. Semi-quantitative calculation based on x-ray diffraction demonstrated that with increasing Y2O3 content, both the crystallinity and the phase content of cristobalite gradually decreased. It is effective for the additive Y2O3 to inhibit the formation of cristobalite phase with a large coefficient of thermal expansion value. The flexural strength and the Young’s modulus, thus, are remarkably increased from 140 MPa to 200 MPa and 56.5 GPa to 63.7 GPa, respectively. Also, the sintering kinetics of BABS glass–ceramics with various Y2O3 were investigated using the isothermal sintering shrinkage curve at different sintering temperatures. The sintering activation energy Q sharply decreased from 99.8 kJ/mol to 81.5 kJ/mol when 0.2% Y2O3 was added, which indicated that a small amount of Y2O3 could effectively promote the sintering procedure of BABS glass–ceramics.

Effects of Y2O3 on the microstructure and mechanical properties of spark plasma sintered fine-grained W-Ni-Mn alloy

Fine-grained W-Ni-Mn-Y2O3 alloys were fabricated by mechanical alloying-assisted spark plasma sintering (SPS), and the effects of Y2O3 content on the microstructure and mechanical properties of the alloys were studied. Fine-grained 90W-6Ni-4Mn-Y2O3 alloys with uniform microstructure and excellent properties were prepared by SPS at 1150 °C. The addition of trace Y2O3 inhibited the sintering densification process and refined the W grain size. The average W grain size decreased from 5.5 μm to 2.1 μm. The fracture mode changed from W grain transgranular fracture and W–W interface fracture to W–W and W-Matrix phase interface fracture. The Rockwell hardness and bending strength of alloys initially increased and then decreased with increasing Y2O3 content. The optimum comprehensive mechanical properties (Rockwell hardness and bending strength) of the alloys were obtained at the same time when the mass fraction of Y2O3 was 0.4%.

Effect of Yttrium Oxide Impurities on the Structure and Properties of Metallic Hafnium

The influence of yttrium oxide impurity content of 0 to 0.4 wt.% on the structure and microhardness metal hafniuminvestigated. It is shown that grain size decreases and the Microhardness of hafnium increases monotonically with increasing content of impurities, while increasing Y2O3 content more than 0.3 wt.% is cracking material.

Quantification of Yttria in Stabilized Zirconia by Raman Spectroscopy

The relationship between Y2O3 content in tetragonal and cubic ZrO2 phases and the shift of the Raman band at ∼645/cm was investigated. With increasing Y2O3 content, the 645/cm Raman band position decreases to lower Raman shift values. A fit of x = Y2O3 content in wt% and y = Raman band position in per cm, was found to be valid for low Y2O3‐stabilized t‐ZrO2, t′′‐ZrO2 transition, and fully stabilized c‐ZrO2. Modeling the change in lattice parameters due to the incorporation of Y2O3 in ZrO2 as obtained from Rietveld‐refined XRD data confirms that the peculiar sigmoidal form of the band shift with Y2O3 content is mainly due to a variation of the amount of oxygen vacancies. The resultant method is highly attractive in fields of Y2O3 determination in ZrO2 materials where a fast, spatially resolved, and nondestructive analysis is required.

Effect of intermediate oxide (Y2O3) on thermal, structural and optical properties of lithium borosilicate glasses

Glass and glass ceramic samples with composition 55SiO2–30B2O3–(x)Li2O–(15−x)Y2O3, where x=0, 5, 10, 15 are prepared by conventional melt-quench technique. The structural, physical, thermal, optical, mechanical and conducting properties of these glasses are studied using X-ray diffraction (XRD), Differential Thermal Analyzer (DTA), Fourier Transform Infrared spectroscopy (FTIR), UV–visible spectroscopy and Impedance spectroscopy. Theoretical elastic moduli are calculated for the better understanding of the glass network strength. All samples, except with x=0 glass, are amorphous in nature. Two broad halos are observed in x=5 and x=10 glasses, indicating phase separation in these glasses. Optical band gap of the samples decreases with increasing Y2O3 content. The lowest band gap is observed ∼3.60eV for x=15 glass. Urbach energy increased with an increase in Y2O3 concentration. Y2O3 played different roles at different concentrations and enhanced the phase separation tendency in glass. The typical conductivity was observed ∼10−6S/cm at 620°C for x=10 glass.

Density, Electrical and Optical Properties of Yttrium-Containing Tellurium Bismuth Borate Glasses

60B2O3-30Bi2O3-(10 − x) TeO2-xY2O3 mol.% (x = 0, 0.1, 1, 2 and 5) glasses have been prepared by the conventional glass-melting technique. The influence of Y2O3 on the density, optical and electrical properties of the glass was investigated. The density decreased whereas the molar volume increased with increasing Y2O3. Optical transmission in the ultraviolet (UV) spectral region indicated that the values of direct and indirect optical band gap energies increased, which was attributed to structural changes induced by the addition of Y2O3. Urbach energy values decreased with increasing the Y2O3, which was attributed to a decrease in the broadening due to static disorder-related parts. Fourier transform infrared (FTIR) spectra revealed that the addition of Y2O3 transforms BO4 to BO3 and BiO3 to BiO6 groups. The decrease in the dc and ac electrical conductivities was attributed to the formation of [BiO6] units which leads to a decrease in acceptor levels of Bi5+ sites. The electric modulus formalism indicated that the conductivity relaxation at different frequencies was a temperature-independent dynamic process. The full width at half-maximum (FWHM) of the normalized modulus decreases with increasing Y2O3 content, suggesting that the decrease of the Y ion–ion distance increases the interaction between the Y ions.

Influence of yttrium ions on the emission transfer features of Ce3+/Yb3+ co-doped lithium silicate glasses

Optical absorption and photoluminescence spectra (PL) of the glasses possessing compositions (49−x) Li2O−x Y2O3−50 SiO2:1.0 Ce2O3/1.0Yb2O3 and (49−x) Li2O−x Y2O3−50 SiO2:(0.5 Ce2O3+0.5 Yb2O3) with x varying from 5 to 15mol% were studied. The PL spectra of Ce3+ doped glasses excited at 360nm exhibited two broad parity allowed 5d(2D)→4f(2F5/2,7/2) bands in the blue spectral region, whereas the spectra of Yb3+ doped glasses excited at 900nm exhibited a broad emission band centered at about 980nm due to 2F5/2→2F7/2 transition. A significant enhancement in the intensity of NIR emission is observed due to the sensitization with Ce3+ ions. The increase in the rate of energy transfer from Ce3+ to Yb3+ could be observed with increasing Y2O3 content. The reasons for such improvement have been discussed within a framework of structural modifications taking place in the vicinity of Yb3+ ions.

Proton Conductivity of Amorphous Hydrated Zirconia-Yttria Solid Solutions

Mechanical mixtures of zirconia xerogel with variable content of crystalline Y2O3 up to 25 mol%, were hydrothermally treated by microwave route at 110 °C for 2 hours in the presence of 0.2 M solution of (KOH+K2CO3) mineralizer. The resulting amorphous hydrated zirconia-yttria solid solutions with a maximum solubility of Y2O3 content between 20 ~ 25 mol%, showed a remarkable reduction of the surface area at the increasing Y2O3 content of the starting mixture. The as-synthesized products and the corresponding calcined powders at 400 °C were uniaxially pressed into pellets (10 x 7 x 2 ~ 4 mm, in width) at 150 MPa. Conductivities were measured at 25 °C by AC impedance method with a frequency range from 10 Hz to 1 MHz with the pellets equilibrated either under silica gel or under increasing relative humidity (RH) up to ~90 %. The effects of composition, surface area, calcination temperature and relative RH on the proton conductivity of the amorphous solid solutions are discussed.