Effect Of Yttrium Oxide Research Articles

Self-Propagating High Temperature Synthesis of Composite Material Based on Zirconium and Chromum Oxide

Ceramic composite materials based on stabilized zirconium oxide were obtained by self-propagating high-temperature synthesis. Yttrium oxide was used as a stabilizing additive. The work studied the effect of the content of yttrium oxide additive on the temperature and combustion rate of the materials studied. Also, based on the results of X-ray phase analysis and scanning electron microscopy, the effect of yttrium oxide on the phase composition and microstructure of the synthesized materials was studied.

Effect of yttrium oxide on microstructure and mechanical properties of functionally graded magnesium matrix composites

Over the last decade, there has been a steady increase in the amount of magnesium scrap sourced from manufacturing processes due to the rapidly growing market for magnesium alloys in various industries. As a result, the reuse of magnesium becomes extremely beneficial for cost reduction, natural resource preservation, and environmental protection, as it gives scrap magnesium a new lease on life. The reuse of AZ91 magnesium alloy chips for producing functionally graded composites reinforced with yttrium oxide (Y2O3) to enhance microstructure and mechanical properties was investigated in this paper. The manufacturing method for this study involves: (1) collecting and cleaning magnesium chips, (2) pre-mixing them with Y2O3 particles, (3) melting and blending the compositions using a stir casting method, and (4) finally pouring it into a centrifugal casting to produce the functionally graded composite. The microstructure of the AZ91 matrix was examined, and it indicated a well-distributed gradient of Y2O3 particles with little agglomeration. The estimated concentration of particles (which ranged from 40.35% to 32.1% area) closely matched the experimental data (which ranged from 43% ± 1.5% to 28% ± 1.5% area). The study also revealed that particle concentration had a substantial influence on the mechanical properties, with the outer zone outperforming both the middle and inner zones. In the outer zone, the gradient composite had a hardness of 106.89 ± 1.25 HV, a tensile strength of 197.39 ± 2 MPa, and a compressive strength of 335.29 ± 5 MPa. Furthermore, the findings demonstrated the feasibility of employing chip waste to make graded composites, providing a feasible technique for reusing magnesium chips created during machining procedures. This research sheds new light on the use of magnesium chips as a matrix material in the casting of functionally graded composites.

Effect of Yttrium Oxide in Hydroxyapatite Biocomposite Materials: Electrical and Antimicrobial Evaluation

Synthesis and characterization of biocomposite materials of hydroxyapatite (HA) and yttrium oxide (Y2O3) were investigated. HA nanoparticles powder was obtained from mussel shells via a wet chemical precipitation routine. HA powder was doped with 1 and 2 wt% of Y2O3. For microstructural examination, X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), and scanning electron microscopy (SEM) coupled with energy dispersive X-rays (EDX) were used. In addition, the dielectric and electrical properties and antimicrobial activities were investigated. XRD patterns reveal the crystallization of the oxyapatite. The peak intensities of pristine HA are inferior compared to the yttrium containing HA composites, thus suggesting that the addition of yttrium promotes the crystallization of HA due to the variance in their ionic radii. FT-IR shows a variation in the phosphate wavenumber, indicating the integration of yttrium into the HA matrix. SEM reveals nanorod- or worm-like crystals arose in clusters. With increasing Y2O3, from 1 to 2 wt%, the DC conductivity reduces from 16 to 9.3 nS/cm, which confirms that high amounts of Y3+ substitute Ca2+ in the HA matrix. In the high-frequency range, the AC conductivity linearly increases with increasing frequency following the universal power law. Further, antimicrobial activity results showed that the addition of yttrium in HA improves the antimicrobial effects against pathogenic bacteria and fungi. Additional research is needed to investigate the doping concentration of yttrium ions, and an anticipated property could be comprehended for several forthcoming biomedical applications.

Effect of Yttrium Oxide on Mechanical and Physical Properties of Fe–10%Cu Composite

Iron-based composites have found a lot of industrial applications such as bearings, camshafts, connecting rods, pulleys, various valves, oil pump gears and many other applications in the automotive and other industries due to their low cost, availability, and high strength. The present study aims to prepare Fe-10 vol.% Cu - (0 – 5) wt.% nano Y2O3 composites by powder metallurgy technique and studying their physical and mechanical properties. The powders were mixed into ball mill for 30 minutes, followed by room temperature uniaxial compaction at 700 MPa for 3 minutes. The green specimens were sintered at 1000 oC for 1 hour. The results of the present study showed that nano yttrium oxide has significant effects on both physical and mechanical properties of Fe-10%Cu composite. The bulk density was increased by 0.92% and the true porosity was decreased by 6.4% on increasing the nano oxide content from 0% to 3% respectively. Vickers microhardness was increased by 5.9% on increasing Y2O3 up to 1% followed by gradual decrease on further increase above 1%. Wear rate was decreased by 21% on increasing the nano oxide content from 0% to 3%. On the other hand, the compressive strength was decreased by 47% on increasing Y2O3 up to 5%.

The effect of yttrium oxide in hydroxyapatite/aluminum oxide hybrid biocomposite materials: Phase, mechanical and morphological evaluation

AbstractThis study presents the fabrication and characterization of composite materials of hydroxyapatite and aluminum oxide. Hydroxyapatite powder was obtained from bovine bones via conventional calcination routine. Although hydroxyapatite shows great biocompatibility with the human body, its applications are limited to non‐load bearing areas. For this purpose, fine powders of hydroxyapatite/alumina were admixed with 1 and 5 wt.% yittria. Powder‐compacts were sintered by two‐step sintering route by increasing temperature to 1550 °C for 2 h and then sintering at 1450 °C for 4 h. The effect of increasing yittria content on sintering behavior and mechanical properties was investigated in biocomposite hybrid materials.

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.

Yttrium oxide passivation of porous silicon nanostructures for improved photoluminescence and optoelectronic properties

This paper reports on the effect of yttrium oxide as a novel treatment to improve the photoluminescence (PL) intensity and stability of porous silicon (PS). Yttrium oxide (Y2O3) was incorporated into the PS layers by impregnation method using a saturated aqueous solution. The penetration of yttrium into the PS microstructure was examined using the Energy dispersive X-ray spectrometry (EDS) and the backscattered electron detector (BED-C) for composition imaging and analysis. The morphology of the front surface was studied using a field emission scanning electron microscope. The deposited yttrium oxide onto the PS layers was thermally activated to passivate efficiently the silicon dangling bonds, and prevent the PS from huge oxidation. The PL peak intensity of impregnated PS was increased noticeably compared to the as-prepared untreated PS. Unlike the as-prepared PS photoluminescence dependence with aging, the yttrium-passivated PS layers PL peak shows no shifts during aging allowing a high stability. Furthermore, we obtained a significant improvement of the effective minority carrier lifetime (τeff) after a short anneal at 600 °C, while increasing the temperature reduces noticeably the passivation properties. The improved surface passivation experienced after the thermal annealing can be ascribed to yttrium diffusion into the PS layer, with a resulting redistribution of yttrium oxide and subsequent passivation of silicon dangling bonds in the sub-interface region, this was confirmed by EDS analysis. The internal quantum efficiency measurements were performed to study the optoelectronic properties of the processed monocrystalline silicon substrates.

Influence of Y on microstructures and mechanical properties of high strength steel weld metal

A comprehensive investigation is conducted into the effect of yttrium oxide on microstructures of weld metal deposits and mechanical properties of high strength steel electrode measured in the Ni–Cr–Mo–V alloy system. The results demonstrate a gradual decrease of the content of proeutectoid ferrites and a gradual increase of acicular ferrites, as the content of yttrium oxide increases from 0% to 0.02%. However, as the content of yttrium oxide surpasses 0.02%, the content of acicular ferrites reduces significantly. Meanwhile, the toughness under low-temperature impact increases and then decreases, as the content of yttrium varies from 0% to 0.03%, reaching the maximum of 102J at the field of 0.02%. However, the strength fails to change significantly. The results also indicate that the cold cracking sensitivity is lower when the content of yttrium oxide is 0.02%, but the values would increase as the content of yttrium oxide fluctuates.

Effect of Yttrium Oxide on the Viscosity and Crystallization of Borosilicate Glass at High Temperature

Effect of Y2O3 on the viscosity and Crystallization of of borosilicate glass at high temperature was investigated at high temperature. Melt viscosity as a function of temperature was determined by using a rotating spindle viscometer. Liquidus temperature was determined by the Gradient Furnace Method. The results show that the viscosity decreased as a function of Y2O3 content. The activation energy of glass without Y2O3 is about 110.3 kJ·mol-1 and the activation energy increases with the Y2O3 addition up to the 2 wt%. At 2 wt% Y2O3, the specimen shows the maximum activation energy value of 112.6 kJ·mol-1. As Y2O3 content increase, the activation energy decreases. The fiber-forming temperature of glass without Y2O3 is about 1342 oC and the fiber-forming temperature increases with the Y2O3 addition up to the 2 wt%. At 2 wt% Y2O3, the sample shows the maximum activation energy value of 1370 °C. When Y2O3 content increase, the fiber-forming temperature decreases. The liquidus temperature of glass decreases from 1313 °C to 1023 °C when Y2O3 content increases from 0 wt% to 6 wt%. The difference between the fiber-forming and the liquidus temperatures of glass increases from 30 oC to 336 °C when Y2O3 content increases from 0 wt% to 6 wt%.

Effect of the percentage of yttrium oxide on the phase composition of annealed samples of Y z Ba5Cu7O y and Y z Ba3Cu5O y composition

The phase composition of YzBa5Cu7Oy (1) and YzBa3Cu5Oy (2) samples with a variable percentage of yttrium up to the stoichiometric composition of the YnBamCum + nOy series is investigated by X-ray phase and elemental analyses, electron diffraction, and high resolution imaging in a transmission electron microscope at a temperature of 930°C in the crystallization field of a matrix oxide (Ba: Cu) of 5: 6 composition on the phase diagram of the BaO-CuOx system at P(O2) = 21 kPa. The substantial effect of yttrium oxide’s presence on the phase composition of both objects is found, providing evidence of a complex ionic equilibrium within the melt. The fine-domain oxide structure of the YBa2Cu3O6 tetragonal form, which is due to the coexistence of oxides of an YnBamCum+nOy homologous series of (Y: Ba: Cu) 235, 123, and 257 composition is revealed. The domain size for these phases is 20–50 A. The domains are joined coherently along axis c.

Effect of yttrium oxide on the formation of the phase composition and porous structure of titanium dioxide

The formation of the structure of TiO2 (anatase) doped with 1–5 mol % Y2O3 is reported. The dopant changes the anatase structure from regular to nanocrystalline. The nanocruystalline structure consists of incoherently intergrown 5- to 7-nm anatase crystallites (500°C) separated by interblock boundaries accommodating yttrium ions. The formation of the nanocrystalline anatase structure stabilizes small anatase crystallites and raises the anatase-to-rutile phase transition temperature above 900°C. Owing to this structure, the developed specific surface area and fine porous texture of yttrium oxide-doped titanium dioxide survive up to higher temperatures than those of undoped titanium dioxide.

Corrosion and protection characteristics of phosphate coatings: effect of yttrium oxide as additive

The corrosion and protection characteristics of phosphate coatings formed in a phosphating solution containing mainly ZnO, H3PO4 and NaF, using Y2O3 as an additive, were investigated through SEM, polarisation curves and EIS diagrams. The results show that the corrosion protection of phosphate coatings has been improved when Y2O3 is added to the phosphating solution, making the free corrosion potential shift to the positive direction and causing the corrosion current to decrease. The protection ability of phosphate coatings depends mainly on their barrier performance. The phosphate coatings formed in the phosphating solution with 10 and 20 mg L–1 Y2O3 have finer crystal structures and smaller porosity; therefore, they exhibit better corrosion resistance and adhesion properties than those without Y2O3 and with 40 mg L–1 Y2O3.

The effect of yttrium oxide on the sintering behavior and hardness of tungsten

In this study, the relative density and hardness of Y2O3 dispersed tungsten alloy were investigated as functions of the Y2O3 content and sintering temperature. The sintering temperature and the amount of the second phase were varied from 1800 to 2500°C and 0 to 2.0 weight pct, respectively. The relative density of the alloys is higher than that of pure tungsten in the range from 2000 to 2500°C, whereas the density is lower at 1800°C. As the Y2O3 content increases, the sintered density increases at a given temperature. The transition temperature (Ttr), where the relative density of the alloys exceeds that of pure tungsten, is reduced with increased Y2O3 particle content. In order to examine the effect of the second phase on the mechanical property, the hardness of pure tungsten and the alloys are measured. The hardness is mainly dependent upon the relative density of the alloys, rather than the amount of the second phase and tungsten grain size. The relationship between hardness and density is discussed according to the plasticity theory of porous materials.

The Effect of Yttrium Oxide on the Microstructure and Properties of Ceramics Based on Lanthanum Hexaaluminate Synthesized by the Sol–Gel Method

The effect of a sintering aid, yttrium oxide, on the properties of ceramic materials based on lanthanum hexaaluminate synthesized by a sol–gel method is studied. The synthesis of a sol of ternary oxide composition conducted via hydrolysis of a mixed salt solution leads to the formation of particles with a “nucleus – shell”-type structure. The synthesis of lanthanum hexaaluminate with the participation of these particles proceeds at 1000 – 1100°C, and the sintering of ceramic at 1400 – 1500°C. Ceramic based on yttrium-containing lanthanum hexaaluminate exhibits improved strength properties.

Preparation and properties of Y 2O 3 containing zirconia–mullite composites derived from sillimanite beach sand

Mullite–zirconia composites with 2–6 mol% yttrium oxide have been prepared from Indian coastal sillimanite beach sand, zirconia and alumina. All raw materials have been attrition milled and then isostatically pressed followed by sintering in the range of 1500–1600 °C with a 2-h soaking period. Then the sintered materials have been characterised in terms of bulk density, linear shrinkage, hot modulus of rupture, X-ray diffraction, infra red spectroscopy and microstructural features. The effect of yttrium oxide with change of sintering temperature for different properties have been discussed.