The Experts below are selected from a list of 1950 Experts worldwide ranked by ideXlab platform
Aiying Wang - One of the best experts on this subject based on the ideXlab platform.
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Transforming the amorphous Ti-Al-C coatings to high-purity Ti2AlC MAX phase coatings by Prolonged Annealing at 550 °C
Materials Letters, 2020Co-Authors: Zhenyu Wang, Cuicui Wang, Aiying WangAbstract:Abstract Ti2AlC MAX phases have been considered as the promising protective coating materials in nuclear energy and other harsh environments due to their unique properties. However, high preparation temperatures of Ti2AlC coatings, generally ≥700 °C, are the main barriers to their further application on temperature-sensitive substrates. Taking the concept of surface dynamics during Prolonged Annealing at low-temperatures, herein we reported a quite facile strategy to fabricate high-purity Ti2AlC coatings by transforming amorphous Ti-Al-C coatings at 550 °C. The transformation mechanisms of Ti2AlC MAX phase were also discussed in terms of their microstructural evolutions.
Minghung Tsai - One of the best experts on this subject based on the ideXlab platform.
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on the phase constituents of four cocrfenix x y ti zr hf high entropy alloys after Prolonged Annealing
Journal of materials research and technology, 2020Co-Authors: Anchen Fan, Minghung TsaiAbstract:Abstract Despite the large amount of literature on high entropy alloys (HEAs) in recent years, reports on the equilibrium/near-equilibrium phase and microstructure of HEAs are still very limited. Here, we investigate the phase constituents of four CoCrFeNiX (X = Y, Ti, Zr, Hf) HEAs after Prolonged Annealing. It is found that the alloys typically contain two major phases – a dominating intermetallic (IM) phase and a BCC phase. The major phases in general remain unchanged regardless of Annealing temperature. Annealing at lower temperatures, however, typically leads to the formation of new minor phases. In particular, the formation of σ phase during Annealing is observed in all the alloys. Existing phase formation theories are applied to the alloys. The theories successfully predict that the present alloys do not form simple solid solution phases only. Phase-specific stability criteria also explain the prevalence of Laves and σ phases quite well.
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on the phase constituents of three cocrfenix x v nb ta high entropy alloys after Prolonged Annealing
Journal of Alloys and Compounds, 2020Co-Authors: Anchen Fan, Minghung TsaiAbstract:Abstract In this work, the phase constituents, microstructures, and phase compositions of three equimolar CoCrFeNiX (X = V, Nb, Ta) high-entropy alloys (HEAs) after Prolonged Annealing were investigated. The results show that all the alloys are composed of two major phases – a dominating intermetallic (IM) phase and an FCC phase. These major phases do not change with Annealing temperature. However, Annealing at 500–900 °C can lead to the formation of new minor phases [i.e. μ, σ, (Ni, Co)3Nb and (Ni, Co)3Ta phases]. Existing phase formation theories were applied to the alloys. It was found that simple solid solution (SSS) HEA prediction models can predict IM formation in CoCrFeNiNb and CoCrFeNiTa, but failed to do so in the case of CoCrFeNiV. This is mainly due to the IM phase type in CoCrFeNiV. On the other hand, phase-specific formation criteria successfully predicted the stability of Laves and σ phases in the alloys. The phase formation trends in the alloys were also compared and discussed.
Zhenyu Wang - One of the best experts on this subject based on the ideXlab platform.
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Transforming the amorphous Ti-Al-C coatings to high-purity Ti2AlC MAX phase coatings by Prolonged Annealing at 550 °C
Materials Letters, 2020Co-Authors: Zhenyu Wang, Cuicui Wang, Aiying WangAbstract:Abstract Ti2AlC MAX phases have been considered as the promising protective coating materials in nuclear energy and other harsh environments due to their unique properties. However, high preparation temperatures of Ti2AlC coatings, generally ≥700 °C, are the main barriers to their further application on temperature-sensitive substrates. Taking the concept of surface dynamics during Prolonged Annealing at low-temperatures, herein we reported a quite facile strategy to fabricate high-purity Ti2AlC coatings by transforming amorphous Ti-Al-C coatings at 550 °C. The transformation mechanisms of Ti2AlC MAX phase were also discussed in terms of their microstructural evolutions.
Andres Cuevas - One of the best experts on this subject based on the ideXlab platform.
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electronic passivation of silicon surfaces by thin films of atomic layer deposited gallium oxide
Applied Physics Letters, 2014Co-Authors: Thomas Allen, Andres CuevasAbstract:This paper proposes the application of gallium oxide (Ga2O3) thin films to crystalline silicon solar cells. Effective passivation of n- and p-type crystalline silicon surfaces has been achieved by the application of very thin Ga2O3 films prepared by atomic layer deposition using trimethylgallium (TMGa) and ozone (O3) as the reactants. Surface recombination velocities as low as 6.1 cm/s have been recorded with films less than 4.5 nm thick. A range of deposition parameters has been explored, with growth rates of approximately 0.2 A/cycle providing optimum passivation. The thermal activation energy for passivation of the Si-Ga2O3 interface has been found to be approximately 0.5 eV. Depassivation of the interface was observed for Prolonged Annealing at increased temperatures. The activation energy for depassivation was measured to be 1.9 eV.
Cuicui Wang - One of the best experts on this subject based on the ideXlab platform.
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Transforming the amorphous Ti-Al-C coatings to high-purity Ti2AlC MAX phase coatings by Prolonged Annealing at 550 °C
Materials Letters, 2020Co-Authors: Zhenyu Wang, Cuicui Wang, Aiying WangAbstract:Abstract Ti2AlC MAX phases have been considered as the promising protective coating materials in nuclear energy and other harsh environments due to their unique properties. However, high preparation temperatures of Ti2AlC coatings, generally ≥700 °C, are the main barriers to their further application on temperature-sensitive substrates. Taking the concept of surface dynamics during Prolonged Annealing at low-temperatures, herein we reported a quite facile strategy to fabricate high-purity Ti2AlC coatings by transforming amorphous Ti-Al-C coatings at 550 °C. The transformation mechanisms of Ti2AlC MAX phase were also discussed in terms of their microstructural evolutions.
