Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 3

Al2O3 Related Publications

3 Experimental Study on Thermomechanical Properties of New-Generation ODS Alloys

Authors: O. Khalaj, B. Mašek, H. Jirková, J. Svoboda

Abstract:

By using a combination of new technologies together with an unconventional use of different types of materials, specific mechanical properties and structures of the material can be achieved. Some possibilities are enabled by a combination of powder metallurgy in the preparation of a metal matrix with dispersed stable particles achieved by mechanical alloying and hot consolidation. This paper explains the thermomechanical properties of new generation of Oxide Dispersion Strengthened alloys (ODS) within three ranges of temperature with specified deformation profiles. The results show that the mechanical properties of new ODS alloys are significantly affected by the thermomechanical treatment.

Keywords: Alloys, Hot Forming, Al2O3, thermomechanical, ODS, Fe-Al

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2 Thermal Conductivity of Al2O3/Water-Based Nanofluids: Revisiting the Influences of pH and Surfactant

Authors: Sebastien Poncet, Nizar Bouguerra, Ahmed Khabou, Saïd Elkoun

Abstract:

The present work focuses on the preparation and the stabilization of Al2O3-water based nanofluids. Though they have been widely considered in the past, to the best of our knowledge, there is no clear consensus about a proper way to prepare and stabilize them by the appropriate surfactant. In this paper, a careful experimental investigation is performed to quantify the combined influence of pH and the surfactant on the stability of Al2O3-water based nanofluids. Two volume concentrations of nanoparticles and three nanoparticle sizes have been considered. The good preparation and stability of these nanofluids are evaluated through thermal conductivity measurements. The results show that the optimum value for the thermal conductivity is obtained mainly by controlling the pH of the mixture and surfactants are not necessary to stabilize the solution.

Keywords: Nanofluid, Stability, Dispersion, Thermal Conductivity, Preparation, surfactant, Al2O3, transient hot wire

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1 Preparation and Evaluation of New Nanocatalysts for Selective Oxidation of H2S to Sulfur

Authors: Mohammad Kazemeini, Moslem Fattahi, Mohammad Rezaee, Ali Morad Rashidi

Abstract:

Selective oxidation of H2S to elemental sulfur in a fixed bed reactor over newly synthesized alumina nanocatalysts was physio-chemically investigated and results compared with a commercial Claus catalyst. Amongst these new materials, Al2O3- supported sodium oxide prepared with wet chemical technique and Al2O3 nanocatalyst prepared with spray pyrolysis method were the most active catalysts for selective oxidation of H2S to elemental sulfur. Other prepared nanocatalysts were quickly deactivated, mainly due to the interaction with H2S and conversion into sulfides.

Keywords: H2S, Al2O3, Claus process, Spray pyrolysis method, Wet chemical technique

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