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Characterization of Al 6061/Al2O3/SiC composites with cerium oxide: corrosion analysis and microstructural insights

Sharma Vipin Kumar, Kumar Pardeep, Kumar Dinesh, Chalisgaonkar Rupesh, Akhai Shalom

Composites Theory and Practice

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2024

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R. 24, nr 1

49--56

EN

CeO2) is incorporated, employing electrochemical analysis and scanning electron microscopy (SEM) techniques. This study investigated the impact of cerium oxide on the corrosion behavior and assessed the hydrophobic properties of the composite surface in corrosive environments using contact angle measurements. The experimental methodology comprised several key components, like the selection of specific materials, the production of hybrid composites by the stir casting technique, the analysis of corrosion using the potentiodynamic polarization method, and the characterization of surface wettability. The metallographic analysis of the composites provided insights into the impact of various reinforcements on the microstructural properties. The incorporation of cerium oxide served to mitigate agglomeration and augment grain refinement within the composites. The utilization of potentiodynamic polarization analysis revealed enhanced corrosion resistance in hybrid composites containing cerium oxide in comparison to the Al 6061 alloy. The corrosion current density exhibited a decrease as the content of CeO2 increased. The findings indicate that cerium oxide can effectively prevent corrosion in aluminum hybrid, composites. These composites show potential for use in corrosion-prone applications.

2

Synthesis and Thermal Properties of Europium-Cerium Oxide as a New Fluorite-Type Ceramic Material for Thermal Barrier Coatings Applications

Mikuśkiewicz M., Stopyra M., Moskal G.

Archives of Metallurgy and Materials

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2018

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Vol. 63, iss. 4

2089--2093

EN

In the present paper the structure and thermal properties of europium cerium oxides were investigated. The material for the research was obtained via solid state synthesis. The initial powders: ceria CeO2 and europia Eu2O3 were mixed in 1:1 mass ratio (non-stoichiometric proportion with the excess of CeO2) and milled. The sintering process was performed using high temperature vacuum press at 1350°C. Calorimetric analysis was conducted both for initial powders and milled mixture. The structure, phase composition and thermal diffusivity of obtained material were investigated in as-sintered condition. It was revealed that the obtained material was multi-phase. Non-stoichiometric phases including Ce0.5Eu0.5O1.75 with fluorite type structure and different lattice parameters were present. Thermal diffusivity decreased in the range from 25 to 900°C from 1.49 to 0.57 mm2 /s and then increased to 0.70 mm2 /s at 1400°C.

3

Wpływ nanocząstek tlenku ceru na aktywność powierzchniową surfaktantu płucnego

Kondej D., Sosnowski T. R.

Rocznik Ochrona Środowiska

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2016

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Tom 18, cz. 2

146--157

EN

In recent years there has been an intensive development of industries that use or produce materials in the nano scale. Nanomaterials contribute to the improvement of the product parameters, but when inhaled can also negatively affect the human body. The aim of the study was to investigate the effect of cerium oxide nanoparticles on the surface activity of pulmonary surfactant (PS) forming a thin film separating the inhaled air from the alveolar epithelium. Three types of cerium oxide powders were used (Sigma-Aldrich): C1 having a particle size smaller than 25 nm, C2 having a particle size smaller than 50 nm, and for comparison purposes C3 having a particle size smaller than 5 µm. Measurement of specific surface area was carried out using a Gemini 2360 surface area analyzer (Micromeritics, USA). The effect of cerium oxide nanoparticles on the surface activity of PS was studied using DeltaPi microtensiometer (Kibron Inc., Finland). Reconstituted animal surfactant preparation (Beractantum; Abbott Laboratories, France) recommended in states of deficiency of endogenous PS in newborn premature infants, was used as model PS. The tests were carried out at different particle concentrations (ranging up to 1 mg/ml) prepared with the constant concentration of the surfactant solution (1.25 mg phospholipids/ml). The study showed that in all the analyzed cases, the presence of cerium oxide particles caused an increase in surface pressure (lowering of the surface tension) at the liquid-air interface. It was found that the intensity of these changes depends on the particle size, specific surface area and the particle concentration. With the increase in concentrations of the particles in the model surfactant suspension, a greater difference in surface pressure/tension was observed with respect to the initial value. The largest increase in surface pressure (6.4 ± 1.1 mN/m) was observed in the presence of cerium oxide nanoparticles C1, which were characterized by the smallest dimensions (smaller than 25 nm) and the largest surface area (33.3 m2/g). The results show that cerium oxide nanoparticles may have an influence on the surface activity of pulmonary surfactant in vivo and adversely affect the functioning of the human respiratory system.

4

Synthesis and Thermal Properties of Cerium-Dysprosium Oxide

Mikuśkiewicz M., Stopyra M., Moskal G.

Archives of Metallurgy and Materials

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2016

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Vol. 61, iss. 2B

965--969

EN

The paper presents results of investigation on synthesis and characterization of cerium-dysprosium oxide. The input powders - dysprosium oxide Dy,sub>2O3 and cerium oxide CeO2 - were mixed so as to obtain equimolar ratio of cations, milled in alcohol and synthesized via solid state reaction process at 1350°C under 15MPa in vacuum for 2h. The microstructure, phase composition and thermal properties were analyzed. The obtained material was multiphase. Non-stoichiometric compounds were identified. Thermal diffusivity of investigated material decreased in the temperature range of 25-1000°C from 0,71 to 0,45 mm2/s.

5

Preparation and microstructural characterization of Si(100) Ce1−x Gd x O2−δ thin films prepared by pulsed laser deposition technique

Nagaraju P, Vijayakumar Y, Phase D M, Reddy V R

Materials Science Poland

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2014

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Vol. 32, No. 4

541--546

EN

Microstructural properties of Ce1−xGdxO2−δ (x = 0 to 0.3) thin films prepared by pulsed laser deposition technique were studied. The thin films were deposited on Si(100) substrate at a substrate temperature of 973 K at the oxygen partial pressure of 0.2 Pa using KrF excimer laser with energy of 220 mJ. The prepared thin films were characterized by X-ray diffraction, Raman spectroscopy and atomic force microscopy. X-ray diffraction analysis confirmed the polycrystalline nature of the thin films. Crystallite size, strain and dislocation density were calculated. The Raman studies revealed the formation of Ce–O with the systematic variation of peak intensity and full width half maxima depending on concentration of gadolinium dopant. The thickness of the films was estimated using Talystep profiler. The surface roughness was estiamted based on AFM.

6

Charakterystyka spektrofotometryczna szkieł odbarwianych cerem i neodymem.

Kokoszka J., Cholewa-Kowalska K., Łączka M.

Szkło i Ceramika

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2007

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R. 58, nr 2

38-42

PL

W pracy oceniono, przy pomocy pomiarów spektrofotometrycznych, efektywność procesu odbarwiania związkami ceru i neodymu szkieł wytopionych z piasków szklarskich o zawartościach Fe2O3 od 0,008-0,05% wag. Wykazano, że zastosowanie mieszanki Nd2O3+CeO2 nie daje pożadanego efektu odbarwiającego przy szkłach wytopionych z piasków o małej zawartości żelaza, efekt ten jest widoczny natomiast przy piaskach silnie zanieczyszczonych żelazem - klasa IV.

EN

The aim of the present paper is the estimation of the effectiveness glass decolourisation applying cerium and neodymium compounds. In glass melting process are used various types of silica sand, with concentration Fe2O3 0,008-0,05% wt. From our results it follows the combination of Nd2O3+CeO2 is very useful for glasses obtained using silica sand with Fe2O3 concentration (class IV). In the case of glass melted with other classes of sand (I-III) the decolourisation efffects are very low.